Diagnostic Aids

Perform this test only when instructed to. VLCM is located on left side of vehicle, behind front grille. This test is only intended to diagnose the following:

• Variable Load Control Module (VLCM).
• Powertrain Control Module (PCM).
• Wiring harness circuits associated with VLCM.

Fig 1: Identifying VLCM Connector Terminals

Fig 2: VLCM Schematic & Test Circuits

1. 1) DTC P1484: Attempt To Regenerate Code  DTC P1484 indicates an open VLCM PWR GND circuit (terminal No. 1). Possible causes are an open VLCM PWR GND circuit or faulty VLCM. Clear DTCs. Start engine, turn A/C on and wait 15 seconds. Turn A/C and ignition off. Check for continuous memory DTCs. If Continuous Memory DTC P1484 present (hard code), go to next step. If Continuous Memory DTC P1484 is not present (intermittent), go to step 4).
2. 2) Check VLCM PWR GND Circuit  Turn ignition off. Disconnect and inspect VLCM connector. Clean or repair connector as necessary. Measure resistance between negative battery terminal and terminal No. 1 (Black wire) at VLCM wiring harness connector. If resistance is less than 5 ohms, replace VLCM. Reconnect all components. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If resistance is 5 ohms or more, locate and repair open in VLCM PWR GND circuit. Reconnect all components. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST .
   NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 2) to step 4). No test procedures have been omitted.
3. 4) Check VLCM PWR GND For Intermittents  Turn ignition off. Visually check VLCM PWR GND circuit between VLCM terminal No. 1 and ground junction. Ground junction is located on left side of radiator support, near battery ground. Disconnect and inspect VLCM connector. Clear or repair connector as necessary. Connect a non-powered test light between VLCM terminals No. 1 (Black wire) and No. 15 (Red wire). Test light should be on. Observe test light for indication of fault (test light will turn off to indicate fault) while shaking and bending VLCM PWR GND circuit (Black wire) between VLCM and ground junction.

   If fault is indicated, isolate and repair open in PWR GND circuit. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST . If fault is not indicated, problem is intermittent and cannot be duplicated at this time.

   NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 4) to step 10). No test procedures have been omitted.
4. 10) DTC P1483: Attempt To Regenerate Code  DTC P1483 indicates that when cooling fan was activated, the Power-To-Cooling Fan circuit exceeded normal current draw. This could be due to a hard fault or an intermittent condition. Possible causes for this fault are:
   • Short to ground in Power-To-Cooling Fan circuit.
   • Faulty cooling fan motor.
   • Faulty VLCM.

   Clear DTCs. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Check for continuous memory DTCs. If Continuous Memory DTC P1483 is present, go to next step. If Continuous Memory DTC P1483 is not present (intermittent), go to step 14).

5. 11) Check Cooling Fan Motor  Clear continuous memory. Disconnect cooling fan motor connector. Start engine. Turn A/C on and wait 15 seconds (but no longer than 20 seconds). Turn A/C and ignition off. Check for continuous memory DTCs. If Continuous Memory DTC P1483 is present, go to next step. Ignore any other DTCs at this time. If Continuous Memory DTC P1483 is not present, replace cooling fan motor. Reconnect all connectors. Repeat QUICK TEST .
6. 12) Check For Short To Ground In Power-To-Cooling Fan Circuit  Turn ignition off. Ensure cooling fan motor connector is disconnected. Disconnect and inspect VLCM connector. Clean or repair connector if necessary. Measure resistance between Light Blue wire at cooling fan connector and negative battery terminal. If resistance is more than 10,000 ohms, replace VLCM. Reconnect all components. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST . If resistance is 10,000 ohms or less, locate and repair short to ground in Light Blue wire. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.
   NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 12) to step 14). No test procedures have been omitted.
7. 14) Check For Intermittent Short To Ground In Cooling Fan Circuit  Turn ignition off. Disconnect cooling fan motor connector. Disconnect and inspect VLCM connector. Clean or repair connector if necessary. Visually inspect Power-To-Cooling Fan circuit between terminal No. 2 (Light Blue wire) of VLCM connector and cooling fan motor connector. Repair wiring as necessary. Connect a non-powered test light between VLCM terminals No. 2 (Light Blue wire) and No. 4 (Yellow wire). Test light should be on, but not at full brightness. Observe test light for indication of fault (test light will get brighter to indicate fault) while shaking, wiggling and bending Power-To-Cooling Fan circuit (Light Blue wire) near cooling fan motor.

   Disconnect cooling fan motor connector. Test light should now be off. Again, observe test light for indication of fault (test light will turn on to indicate fault) while shaking, wiggling and bending Power-To-Cooling Fan circuit (Light Blue wire) between VLCM and cooling fan motor connector.

   If a fault is indicated, isolate fault and repair as necessary. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST . If no fault is indicated, problem is intermittent and cannot be duplicated at this time.

   NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 14) to step 20). No test procedures have been omitted.
8. 20) DTC P1483: Verify Cooling Fan Is Not Always On  Key On Engine Off (KOEO) DTC P1483 indicates an open or short to power in Power-To-Cooling Fan circuit. Possible causes for this fault are:
   • Open or short to power in Power-To-Cooling Fan circuit.
   • Open cooling fan motor ground circuit.
   • Open circuit in cooling fan.
   • Faulty VLCM.
   NOTE: Ensure cooling fan was not turning during KOEO SELF-TEST . If fan was turning, feedback voltage could be sent to VLCM through Power-To-Cooling Fan circuit, resulting in an invalid KOEO DTC P1473.

   Ensure engine is cooled off (cooling fan off). Turn A/C and defroster off. Turn ignition on. If cooling fan is on, go to step 25). If cooling fan is off, go to next step.

9. 21) Check Cooling Fan Ground Circuit  Turn ignition off. Disconnect cooling fan motor connector. Measure resistance between ground and cooling fan ground circuit at cooling fan wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in cooling fan ground circuit. Reconnect all components and repeat QUICK TEST .
10. 22) Check Power-To-Cooling Fan Circuit  Turn ignition off. Disconnect and inspect VLCM connector. Clean or repair connector as necessary. Measure resistance between Power-To-Cooling Fan circuit (Light Blue wire) at cooling fan connector and terminals No. 2 and 3 at VLCM wiring harness connector. If both readings are less than 5 ohms, go to next step. If either reading is 5 ohms or more, locate and repair open in Light Blue wire between VLCM and cooling fan connector. Reconnect all components and repeat QUICK TEST .
11. 23) Check Continuity Of Cooling Fan Circuit  Turn ignition off. Ensure cooling fan is disconnected. Measure resistance between ground circuit (Black wire) and Power-To-Cooling Fan circuit (Light Blue wire) at cooling fan motor connector. If resistance less than 10 ohms, replace VLCM. Reconnect all components, repeat QUICK TEST . If resistance 10 ohms or more, replace cooling fan motor. Reconnect all components, repeat QUICK TEST.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 23) to step 25). No test procedures have been omitted.
12. 25) Check For Short To Power  Turn ignition off. Disconnect cooling fan motor connector. Disconnect and inspect VLCM connector. Clean or repair connector as necessary. Turn ignition on. Measure voltage between ground and Power-To-Cooling Fan circuit (Light Blue wire) at cooling fan motor wiring harness connector. If voltage is less than one volt, replace VLCM. Reconnect all components and repeat QUICK TEST . If voltage is one volt or more, locate and repair short to power in Light Blue wire. Reconnect all components and repeat QUICK TEST.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 25) to step 40). No test procedures have been omitted.
13. 40) DTC P1539: Attempt To Regenerate Code  DTC P1483 indicates that when A/C was activated, the Power-To-Cooling Fan circuit exceeded normal current draw. This could be due to a hard fault or an intermittent condition. Possible causes for this fault are:
    • Short to ground in Power-To-Cooling Fan circuit.
    • Faulty A/C clutch.
    • Faulty VLCM.

    Clear DTCs. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Check for continuous memory DTCs. If Continuous Memory DTC P1483 is present, go to next step. If Continuous Memory DTC P1483 is not present (intermittent), go to step 44).

14. 41) Check A/C Clutch  Clear continuous memory. Disconnect A/C clutch connector. Start engine. Turn A/C on and wait about 15 seconds. Turn A/C and ignition off. Check for continuous memory DTCs. If Continuous Memory DTC P1539 is present, go to next step. Ignore any other DTCs at this time. If Continuous Memory DTC P1539 is not present, repair or replace A/C clutch. Reconnect all connectors. Repeat QUICK TEST .
15. 42) Check For Short To Ground In Power-To-A/C Clutch Circuit  Turn ignition off. Ensure A/C clutch connector is disconnected. Disconnect and inspect VLCM connector. Clean or repair connector as necessary. Measure resistance between POWER-TO-A/C CLUTCH circuit at A/C clutch connector and negative battery terminal. If resistance is more than 10,000 ohms, replace VLCM. Reconnect all components. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST . If resistance is 10,000 ohms or less, locate and repair short to ground in POWER-TO-A/C CLUTCH circuit. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 42) to step 44). No test procedures have been omitted.
16. 44) Check For Intermittent Short To Ground In POWER-TO-A/C CLUTCH Circuit  Turn ignition off. Disconnect A/C clutch connector. Disconnect and inspect VLCM connector. Clean or repair connector if necessary. Visually inspect POWER-TO-A/C CLUTCH circuit between VLCM connector and A/C clutch connector. Repair wiring as necessary. Connect a non-powered test light between VLCM terminals No. 4 and 18. Test light will turn on if fault is located, indicated short to ground. Observe test light for indication of fault while shaking, wiggling and bending POWER-TO-A/C CLUTCH circuit between VLCM and A/C clutch.

    If a fault is indicated, isolate fault and repair as necessary. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST . If no fault is indicated, problem is intermittent and cannot be duplicated at this time. Go to CIRCUIT TEST Z.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 44) to step 50). No test procedures have been omitted.
17. 50) DTC P1530: Attempt To Regenerate Code  DTC P1530 indicates an open or short to power in POWER-TO-A/C CLUTCH circuit. Possible causes for this fault are:
    • Open or short to power in POWER-TO-A/C CLUTCH circuit.
    • Open A/C clutch ground circuit.
    • Open circuit in A/C clutch.
    • Faulty VLCM.

    Clear DTCs. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Check for continuous memory DTCs. If Continuous Memory DTC P1530 is present, go to next step. If Continuous Memory DTC P1530 is not present (intermittent), go to step 55).

18. 51) Check For Short To Power  Turn ignition off. Disconnect A/C clutch connector. Disconnect and inspect VLCM connector. Clean or repair connector as necessary. Turn ignition on. Measure voltage between chassis ground and POWER-TO-A/C CLUTCH circuit at A/C clutch wiring harness connector. If voltage is less than one volt, go to next step. If voltage is one volt or more, locate and repair short to power in POWER-TO-A/C CLUTCH circuit. Reconnect all components. Clear PCM memory. Turn A/C off. Start engine and wait 15 seconds. Turn ignition off. Repeat QUICK TEST .
19. 52) Check Ground Circuit Continuity  Turn ignition off. Leave A/C clutch and VLCM connector disconnected. Measure resistance between POWER-TO-A/C CLUTCH circuit at A/C clutch connector and terminal No. 18 at VLCM wiring harness connector. Measure resistance between chassis ground and A/C clutch ground circuit at A/C clutch wiring harness connector. If both readings are less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit. Clear PCM memory. Turn A/C off. Start engine and wait 15 seconds. Turn ignition off. Reconnect all components and repeat QUICK TEST .
20. 53) Check Continuity Of A/C clutch Circuit  Turn ignition off. Ensure A/C clutch is disconnected. Measure resistance between circuit terminals at A/C clutch connector. If resistance is less than 10 ohms, replace VLCM. Reconnect all components and repeat QUICK TEST. If resistance is 10 ohms or more, replace A/C clutch motor. Clear PCM memory. Turn A/C off. Start engine and wait 15 seconds. Turn ignition off. Reconnect all components and repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 53) to step 55). No test procedures have been omitted.
21. 55) Check For Intermittent Short To B+ In POWER-TO-A/C CLUTCH Circuit  Turn ignition off. Visually inspect POWER-TO-A/C CLUTCH circuit between VLCM connector and A/C clutch connector. Repair wiring as necessary. Turn ignition on. A/C clutch will engage if short to power is located. Observe A/C clutch for indication of fault while shaking and bending POWER-TO-A/C CLUTCH circuit between VLCM and A/C clutch.

    If a fault is indicated, isolate fault and repair as necessary. Repeat QUICK TEST . If no fault is indicated, go to next step.

22. 56) Check For Intermittent Open Circuit  Turn ignition off. Disconnect A/C clutch connector. Disconnect and inspect VLCM connector. Clean or repair connector if necessary. Connect a non-powered test light between A/C clutch connector terminals. Connect jumper wire between battery positive terminal and terminal No. 18 of VLCM. Ensure jumper wire does not contact any other VLCM terminals. Test light should be on. Observe test light for indication of fault (test light will turn off) while shaking, wiggling and bending Power-To-A/C CLUTCH circuit and ground circuit.

    If a fault is indicated, isolate fault and repair as necessary. Reconnect all components and repeat QUICK TEST . If no fault is indicated, problem is intermittent and cannot be duplicated at this time. Go to CIRCUIT TEST Z.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 56) to step 60). No test procedures have been omitted.
23. 60) KOEO/KOER DTC P1625 &/Or DTC P1626  DTC P1625 indicates that B + to VLCM fan circuit is not detected. DTC P1626 indicates that B + to VLCM A/C circuit is not detected. Testing for both DTCs is the same. Possible causes for this fault are:
    • Open B + circuit to VLCM terminals No. 4 and 5.
    • Faulty VLCM.

    Turn ignition off. Disconnect and inspect VLCM connector. Clean or repair connector as necessary. Measure voltage between negative battery terminal and terminals No. 4 (Yellow wire) and No. 5 (Yellow wire) at VLCM wiring harness connector. If both readings are more than 10.5 volts, replace VLCM. Reconnect all components and repeat QUICK TEST . If either reading is 10.5 volts or less, check A/C clutch related fuses. If fuses are okay, locate and repair open in B + circuit. If fuses are blown, locate and repair short to ground in B + circuit. Reconnect all components and repeat QUICK TEST .

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 60) to step 65). No test procedures have been omitted.
24. 65) Continuous Memory DTC P1625 &/Or DTC P1626  Continuous Memory DTC P1625 indicates that an open B (+) supply to VLCM fan circuit has been detected. Continuous Memory DTC P1626 indicates that an open B + supply to VLCM A/C circuit has been detected. Testing for both DTCs is the same. Possible cause for this fault is an intermittent open B + circuit to VLCM terminals No. 4 and 5.

    Turn ignition off. Disconnect and inspect VLCM connector. Clean or repair connector as necessary. Connect a non-powered test light between ground and terminal No. 5 (Yellow wire) at VLCM wiring harness connector. Test light should be on. Observe test light for indication of fault (test light will turn off to indicate fault) while performing the following:

    • Shake, wiggle and bend B + circuit (Yellow wire) to VLCM terminals No. 4 and 5.
    • Lightly tap on cooling fan related fuses. Remove cooling fan related fuses and check for corrosion and damaged pins. Reinstall fuses. If a fault is indicated, isolate fault and repair as necessary. Reconnect all components and repeat QUICK TEST . If no fault is indicated, problem is intermittent and cannot be duplicated at this time.
      NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 65) to step 75). No test procedures have been omitted.

25. 75) DTC 1464: Check ACCS PID  Turn ignition off. Ensure A/C and defroster are off. Connect scan tester to DLC. Turn ignition on. Using scan tester, access ACCS PID. If ACCS is on, go to next step. If ACCS is off, indication is A/C and defrost switch were on during self-test. Turn A/C, defrost switch and all accessories off. Repeat QUICK TEST .
26. 76) ACCS PID On  Turn ignition off. Disconnect A/C cycling switch. Turn ignition on. Using scan tester, access ACCS PID. If ACCS PID does not go off, go to next step. If ACCS PID goes off, check EATC module. If module is okay, check A/C switch and repair or replace as necessary. If A/C switch is okay, repair short to power in A/C demand circuit to A/C cycling switch.
27. Check ACCS Circuit For Short To Power  Turn ignition off. Leave A/C cycling switch disconnected. Disconnect PCM wiring harness connector. Inspect wiring, and repair if damaged. Install EEC-V Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage at breakout box test pin No. 41 (ACCS) and test pins No. 51 and 103 (PWR GND). If voltage is less than one volt, replace PCM and repeat QUICK TEST . If voltage is one volt or more, repair ACCS circuit short to power and re-evaluate symptom.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 77) to step 90). No test procedures have been omitted.
28. 90) KOEO & KOER DTC P0230  For Continuous Memory DTC P0230, go to step 150). If engine will start, go to step 95). If engine will not start, go to next step.
29. 91) Check For Power To VLCM  Turn ignition off. Disconnect VLCM wiring harness connector. Measure voltage between VLCM wiring harness connector terminal No. 15 (VPWR) and negative battery terminal. If voltage is 10.5 volts or more, go to next step. If voltage less than 10.5 volts, repair open in VPWR circuit between VLCM and EEC-V power relay and repeat QUICK TEST .
30. 92) Check FP Circuit Continuity  Leave ignition off and VLCM disconnected. Disconnect PCM 104-pin connector. Inspect pins for damage and repair if necessary. Install EEC-V Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 80 (FP) at breakout box and terminal No. 12 at VLCM wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in FP circuit and repeat QUICK TEST .
31. 93) Check FP Circuit  Leave PCM and VLCM disconnected. Turn ignition on. Measure voltage between test pin No. 80 (FP) and 77 (PWR GND) at breakout box. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair FP circuit short to power and repeat QUICK TEST .
32. 94)  Turn ignition off. Leave PCM disconnected. Reconnect VLCM. Connect jumper wire between test pin No. 80 (FP) and 77 (PWR GND) at breakout box. Turn ignition on. If fuel pump operates, replace PCM and repeat QUICK TEST. If fuel pump does not operate, replace VLCM and repeat QUICK TEST .
33. 95) Check PCM For Short To Ground  Turn ignition off. Disconnect PCM. Turn ignition on. If fuel pump operates, go to next step. If fuel pump does not operate, replace PCM and repeat QUICK TEST .
34. 96) Check FP Circuit For Short To Ground  Turn ignition off. Disconnect VLCM. Disconnect PCM 104-pin connector. Inspect pins for damage and repair if necessary. Install EEC-V Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 80 (FP) and test pins No. 51, 77 (PWR GND) and 91 (SIG RTN) at breakout box. If resistance is more than 10,000 ohms, replace VLCM and repeat QUICK TEST. If resistance is 10,000 ohms or less, repair FP circuit short to ground and repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 96) to step 100). No test procedures have been omitted.
35. 100) KOEO & KOER DTC P0232  If engine will start, go to next step. If engine will not start, go to step 109). For Continuous Memory DTC P0232, go to step 155).
36. 101) Check Fuel Pump  Turn ignition on for 5 seconds. Listen for operational noise from fuel pump. If fuel pump can be heard, go to next step. If fuel pump cannot be heard, go to step 106).
37. 102) Check VLCM  Turn ignition off. Disconnect VLCM. Inspect connector for damage and repair if necessary. Turn ignition on. Listen for operational noise from fuel pump. If fuel pump operates, go to next step. If fuel pump still does not operate, replace VLCM and repeat QUICK TEST .
38. 103) Check High Speed Fuel Pump (HFP) Relay & Circuits  Turn ignition off. Leave VLCM disconnected. Disconnect HFP relay. Turn ignition on. Listen for operational noise from fuel pump. If fuel pump operates, repair circuit short to power, repeat QUICK TEST . If fuel pump does not operate, go to next step.
39. 104)  Turn ignition off. Leave VLCM and HFP relay disconnected. Measure resistance between VLCM wiring harness connector terminal No. 10 (HFP) and negative battery terminal. If resistance is 10,000 ohms or more, replace HFP relay and repeat QUICK TEST . If resistance is less than 10,000 ohms or more, repair HFP circuit short to ground and repeat QUICK TEST.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 104) to step 106). No test procedures have been omitted.
40. 106) Check FPM Circuit Continuity  Turn ignition off. Disconnect High Speed Fuel Pump (HFP) relay (located in power distribution box). Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Measure resistance between test pin No. 40 (FPM) at the breakout box and POWER-TO PUMP circuit at HFP relay wiring harness connector. See Fig 2. If resistance is less than 5 ohms, replace PCM and repeat QUICK TEST . If resistance 5 ohms or more, repair open in FPM circuit between PCM and splice to POWER-TO-PUMP circuit. Repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 106) to step 109). No test procedures have been omitted.
41. 109) Check POWER-TO-PUMP Circuit  Turn ignition off. Disconnect IFS switch. Disconnect High Speed Fuel Pump (HFP) relay. Measure resistance between POWER-TO-PUMP circuit at HFP connector and POWER-TO-PUMP circuit at IFS connector. If resistance less than 5 ohms, go to next step. If resistance 5 ohms or more, repair open in POWER-TO-PUMP circuit and repeat QUICK TEST .
42. 110)  Leave ignition off, HFP relay and IFS switch disconnected. Locate IFS switch in trunk near left hinge. Measure resistance between terminals "C" and NC of IFS switch. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, reset or replace IFS switch and repeat QUICK TEST .
43. 111)  Leave ignition off, HFP relay and IFS switch disconnected. Disconnect fuel pump. Measure resistance between POWER-TO-PUMP circuit at IFS switch connector and POWER-TO-PUMP circuit at fuel pump connector. Measure ground circuit resistance between fuel pump connector and chassis ground. If resistance is less than 5 ohms, reconnect IFS switch and go to next step. If resistance is 5 ohms or more, repair open in POWER-TO-PUMP circuit and repeat QUICK TEST .
44. 112)  Leave ignition off and fuel pump disconnected. Measure resistance between fuel pump terminals. If resistance is less than 10 ohms, fuel pump is okay and testing is complete. If resistance is 10 ohms or more, replace fuel pump and repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 112) to step 115). No test procedures have been omitted.
45. 115) KOEO & KOER DTC P0231: Attempt To Induce DTC P0230 Or P0232  DTC P0230 indicates that FPM circuit did not detect voltage when fuel pump was commanded on. For Continuous Memory DTC PO231, go to step 160). Possible causes for this fault are:
    • Open in B+ supply to VLCM (terminal No. 6).
    • POWER-TO-PUMP or FPM circuit shorted to ground.
    • Power supply fuse to HFP relay damaged.
    • Power circuit to HFP relay shorted to ground.
    • Fuel pump primary circuit fault (DTC P0230 also present).
    • Faulty fuel pump.
    • Faulty VLCM.

    If KOEO DTC P0230 is present, go to step 90). If KOEO DTC P0232 is present, go to step 100). If DTC P0230 or DTC P0232 is not present, go to next step.

46. 116) Check VLCMFPF PID To Determine If DTC Was Set By Over-Current Condition  Turn ignition off. Connect scan tester to DLC. Turn ignition on. Using scan tester, access VLCMFPF PID. If VLCMFPF PID indicates Yes, DTC was set by over-current condition. Go to step 120). If VLCMFPF PID does not indicates Yes, go to next step.
47. 117) Check For Open In B+ Circuit To VLCM  Turn ignition off. Disconnect and inspect VLCM connector. Clean or repair connector as necessary. Measure voltage between VLCM connector terminal and negative battery terminal. If voltage is more than 10.5 volts, replace VLCM and repeat QUICK TEST . If voltage is 10.5 volts or less, check related fuse. If fuse is okay, repair open in B+ circuit to VLCM.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 117) to step 120). No test procedures have been omitted.
48. 120) Check B+ Supply To HFP Relay  Turn ignition off. Check Fuse For B+ Supply To HFP Relay. If fuse is okay, go to next step. If fuse is damaged, go to step 122).
49. 121)  Leave ignition off. Disconnect HFP relay and damaged fuse. Disconnect scan tester from DLC (if applicable). Measure resistance between B+ terminal at HFP relay connector and negative battery terminal. If resistance is more than 10,000 ohms, replace fuse and reconnect HFP relay. Go to next step. If resistance is 10,000 ohms or less, repair short circuit and replace fuse. Repeat QUICK TEST .
50. 122) Check POWER-TO-PUMP & FPM Circuit To IFS Switch For Short To Ground  Leave ignition off. Disconnect IFS switch, PCM and VLCM. Disconnect scan tester from DLC (if applicable). Measure resistance between terminal No. 7 (POWER-TO-PUMP) at VLCM connector and negative battery terminal. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair POWER-TO-PUMP or FPM circuit short to ground and repeat QUICK TEST .
51. 123)  Leave ignition off, IFS switch, PCM and VLCM disconnected. Disconnect fuel pump. Measure resistance between POWER-TO-PUMP circuit at IFS switch connector and negative battery terminal. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair POWER-TO-PUMP circuit short to ground and repeat QUICK TEST .
52. 124) Check VLCM  Leave ignition off, IFS switch and fuel pump disconnected. Reconnect VLCM. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Connect jumper wire between test pin No. 80 (FP) and 77 (PWR GND) at breakout box. While measuring voltage between test pin No. 80 (FP) and 77 (PWR GND) at breakout box, turn ignition on for 2 seconds. If voltage is 8.5 volts or more for 2 seconds, check IFS switch for internal short to ground. If IFS switch is okay, replace fuel pump and repeat QUICK TEST. If voltage is not as specified, replace VLCM and repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 124) to step 130). No test procedures have been omitted.
53. 130) Check POWER-TO-PUMP Circuit Continuity  Turn ignition off. Disconnect IFS switch and VLCM. Measure resistance between terminal No. 7 (POWER-TO-PUMP) at VLCM connector and POWER-TO-PUMP circuit at IFS switch. If resistance is less than 10,000 ohms, replace VLCM and repeat QUICK TEST. If resistance is 10,000 ohms or more, repair open in POWER-TO-PUMP circuit and repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 130) to step 135). No test procedures have been omitted.
54. 135) DTC P1231: Check For B+ To HFP  Turn ignition off. Disconnect HFP relay (located in power distribution box). Measure voltage between B+ terminal at HFP relay wiring harness connector and negative battery terminal. If voltage is 10.5 volts or more, go to next step. If voltage is less than 10.5 volts, check circuit fuse. If fuse is okay, repair B+ or POWER-TO-PUMP circuit short to ground and repeat QUICK TEST .
55. 136)  Leave ignition off and HFP disconnected. Disconnect IFS switch. Measure resistance between POWER-TO-PUMP circuit at IFS switch connector and POWER-TO-PUMP circuit at HFP relay connector. If resistance less than 5 ohms, replace HFP relay and repeat QUICK TEST. If resistance is 5 ohms or more, repair open in POWER-TO-PUMP circuit between HFP relay and splice. Repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 136) to step 140). No test procedures have been omitted.
56. 140) DTC P1235 Or P01236  Turn ignition off. Disconnect HFP relay (located in power distribution box). Turn ignition on. Measure voltage between IGN START/RUN terminal at HFP relay wiring harness connector and negative battery terminal. If voltage is 10.5 volts or more, go to next step. If voltage is less than 10.5 volts, repair open in IGN START/RUN circuit and repeat QUICK TEST .
57. 141) Check Fuel Pump Relay  Turn ignition off. Leave HFP relay disconnected. Measure resistance between terminals No. 85 and 86 at HFP relay. Replace fuel pump relay if resistance is not 40-85 ohms. If resistance is okay, measure resistance between terminal No. 85 and terminals No. 30 and 87 at HFP relay. Replace fuel pump relay if resistance is not 10,000 ohms. If resistance is okay, go to next step.
    Fig 3: Fuel Pump Relay Terminals

    
58. 142) Check HFP Circuit  Leave ignition off and fuel pump relay disconnected. Disconnect VLCM connector. Inspect connector pins for damage and repair as necessary. Turn ignition on. Measure voltage between negative battery terminal and HFP terminal at HFP relay harness connector. If voltage is one volt or less, go to next step. If voltage is more than one volt, repair HFP circuit short to power and repeat QUICK TEST .
59. 143)  Leave ignition off, VLCM and HFP relay disconnected. Disconnect scan tester from DLC (if applicable). Measure resistance between negative battery terminal and HFP terminal at HFP relay harness connector. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair HFP circuit short to ground and repeat QUICK TEST .
60. 144)  Leave ignition off, VLCM and HFP relay disconnected. Measure resistance between terminal No. 10 at VLCM connector and HFP terminal at HFP relay harness connector. If resistance is less than 5 ohms, replace VLCM and repeat QUICK TEST . If resistance is 10,000 ohms or more, repair open in HFP circuit and repeat QUICK TEST.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 144) to step 150). No test procedures have been omitted.
61. 150) Continuous Memory DTC P0230  Turn ignition off. Connect scan tester to Data Link Connector. Turn ignition on and wait 5 seconds. Using scan tester, access FPF PID. Observe FPF PID for indication of fault while wiggling and bending FUEL PUMP circuit between fuel pump relay and PCM. Fault will be indicated by FPF PID is YES. Wiggle and bend FP circuit between PCM and VLCM. Wiggle and bend VPWR circuit between VLCM and EEC-V power relay. Check connectors for clean tight connection. If any faults are found, isolate and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to CIRCUIT TEST Z.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 150) to step 155). No test procedures have been omitted.
62. 155) Continuous Memory DTC P0232  Turn ignition off. Connect scan tester to Data Link Connector. Using scan tester, access FPM PID. Observe FPM PID for indication of fault while wiggling and bending POWER-TO-PUMP circuit between fuel pump, HFP relay and VLCM terminal No. 7. Fault will be indicated by FPM PID turning on. Wiggle and bend FPM circuit between PCM terminal No. 40 and POWER-TO-PUMP circuit splice. Wiggle and bend fuel pump ground circuit. Lightly tap on HFP relay. Check connectors for clean tight connection. If any faults are found, isolate and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to CIRCUIT TEST Z.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 155) to step 160). No test procedures have been omitted.
63. 160) Continuous Memory DTC P0231: Check VLCMFPF PID To Determine If DTC Was Set By Over-Current Condition  Turn ignition off. Connect scan tester to DLC. Turn ignition on. Using scan tester, access VLCMFPF PID. If VLCMFPF PID indicates Yes, DTC was set by over-current condition. Go to step 165). If VLCMFPF PID does not indicates Yes, go to next step.
64. 161) Check B+ Circuit To VLCM For Intermittent Open  Turn ignition off. Disconnect and inspect VLCM connector. Clean or repair connector if necessary. Connect a non-powered test light between negative battery terminal and terminal No. 6 at VLCM wiring harness connector. Test light should be on. Observe test light for indication of fault (test light will turn off to indicate fault) while performing the following:
    • Shake, wiggle and bend B + circuit to VLCM terminal 6 (B+).
    • Lightly tap on related fuses. Remove related fuses and check for corrosion and damaged pins.

    If a fault is indicated, isolate fault and repair as necessary. Reconnect all components and repeat QUICK TEST . If no fault is indicated, go to next step.

65. 162) Check POWER-TO-PUMP Circuit To VLCM For Intermittent Open  Leave ignition off and VLCM connector disconnected. Disconnect Inertia Fuel Shutoff (IFS) switch. Connect a DVOM between negative battery terminal and terminal No. 7 at VLCM wiring harness connector. Turn ignition on. DVOM should indicate more than 7.0 volts (pull-up voltage supplied to FPM/POWER-TO-PUMP circuits by PCM). Observe DVOM for indication of fault (voltage will drop suddenly if open circuit is located) while shaking, wiggling and bending POWER-TO-PUMP circuit between VLCM connector and FPM splice.

    If a fault is indicated, isolate fault and repair as necessary. Reconnect all components and repeat QUICK TEST . If no fault is indicated and DTC P1230 is present, go to CIRCUIT TEST Z. If no fault is indicated and DTC P1230 is not present, symptom could have been set by FP or VPWR fault without setting DTC P0230. Go to step 150).

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 162) to step 165). No test procedures have been omitted.
66. 165) Check POWER-TO-PUMP Circuit Intermittent Short To Ground  Turn ignition off. Disconnect Inertia Fuel Shutoff (IFS) switch. Using scan tester, access FPM PID. Observe FPM PID for indication of fault while wiggling and bending FPM circuit between PCM and splice. Observe FPM PID for indication of fault while wiggling and bending POWER-TO-PUMP circuit as follows:
    • Between HFP relay and VLCM.
    • Between IFS switch and VLCM.

    Fault will be indicated by FPM PID turning off. If any faults are found, isolate and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to CIRCUIT TEST Z.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 165) to step 170). No test procedures have been omitted.
67. 170) Continuous Memory DTC P1235 Or P1236: Check HFP Circuit For Short To Ground  Locate HFP relay in power distribution box. Turn ignition on while listening to HFP relay. A clicking sound will be heard at HFP relay if circuit is shorted to ground. Wiggle and bend HFP circuit between VLCM terminal No. 10 and HFP relay. Check connectors for clean tight connection. If any faults are found, isolate and repair as necessary. If no faults are found, go to next step.
68. 171) Check HFP & IGNITION START/RUN Circuit To VLCM For Intermittent Open  Turn ignition off. Disconnect VLCM connector. Clean or repair connector if necessary. Connect a DVOM between negative battery terminal and terminal No. 10 at VLCM wiring harness connector. Turn ignition on. Observe DVOM for indication of fault (voltage will drop suddenly if open circuit is located) while performing the following:
    • Shake, wiggle and bend HFP circuit between VLCM connector terminal No. 10 and HFP relay.
    • Shake, wiggle and bend IGNITION START/RUN circuit to HFP relay.

    Lightly tap on HFP relay. If a fault is indicated, isolate fault and repair as necessary. Reconnect all components and repeat QUICK TEST . If no faults located, go to next step.

69. 172) Check HFP Circuit For Intermittent Short To Power  Turn ignition off. Leave VLCM connector disconnected and DVOM connected between negative battery terminal and terminal No. 10 of VLCM wiring harness connector. Disconnect HFP relay connector. Turn ignition on. Observe DVOM for indication of fault (voltage will increase if short to power is located) while shaking, wiggling and bending HFP circuit between VLCM connector terminal No. 10 and HFP relay.

    If a fault is indicated, isolate fault and repair as necessary. Reconnect all components and repeat QUICK TEST . If no faults located, problem is intermittent and cannot be duplicated at this time.