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Home >> Lincoln >> 1996 >> Mark VIII Base >> Repair and Diagnosis >> Engine Mechanical >> Engine Cooling Fan >> EEC-V Testing >> Variable Control Relay Module (VCRM) >> Diagnostic Aids
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Diagnostic Aids

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

  1. 1) Code P1484: Attempt To Regenerate Code

    Code P1484 indicates an open VCRM PWR GND circuit (terminal No. 1). Possible causes are an open VCRM PWR GND circuit or faulty VCRM. Clear codes. Start engine, turn A/C on and wait 15 seconds. Turn A/C and ignition off. Check for continuous memory codes. If Continuous Memory Code P1484 is present (hard code), go to next step. If Continuous Memory Code P1484 is not present (intermittent), go to step 4).

  2. 2) Check VCRM PWR GND Circuit

    Turn ignition off. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Check resistance between negative battery terminal and terminal No. 1 (Black wire) at VCRM wiring harness connector. If resistance is less than 5 ohms, replace VCRM. 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 greater, locate and repair open in VCRM 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 VCRM PWR GND For Intermittents

    Turn ignition off. Visually check VCRM PWR GND circuit between VCRM terminal No. 1 and ground junction. Ground junction is located on left side of radiator support, near battery ground. Disconnect and inspect VCRM connector. Clear or repair connector as necessary. Connect a non-powered test light between VCRM 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 performing the following:
    • Shake and bend VCRM PWR GND circuit (Black wire) between VCRM 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) Code P1483: Attempt To Regenerate Code

    Code 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 VCRM.

    Clear codes. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Check for continuous memory codes. If Continuous Memory Code P1483 is present, go to next step. If Continuous Memory Code 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 codes. If Continuous Memory Code P1483 is present, go to next step. Ignore any other codes at this time. If Continuous Memory Code 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 VCRM connector. Clean or repair connector as necessary. Check resistance between Light Blue wire at cooling fan connector and negative battery terminal. If resistance is greater than 10,000 ohms, replace VCRM. 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. Visually inspect Power-To-Cooling Fan circuit between terminal No. 2 (Light Blue wire) of VCRM connector and cooling fan motor connector. Repair wiring as necessary. Connect a non-powered test light between VCRM 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 performing the following:
    • Shake, wiggle and bend 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 performing the following:

    • Shake, wiggle and bend Power-To-Cooling Fan circuit (Light Blue wire) between VCRM 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) Code P1473: Verify Cooling Fan Is Not Always On Key On Engine Off (KOEO)

    Code P1473 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 VCRM.
    NOTE: Ensure cooling fan was not turning during KOEO self-test. If fan was turning, feedback voltage could be sent to VCRM through Power-To-Cooling Fan circuit, resulting in an invalid KOEO Code 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. Check 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 greater, 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 VCRM connector. Clean or repair connector as necessary. Check resistance between Power-To-Cooling Fan circuit (Light Blue wire) at cooling fan connector and terminals No. 2 and 3 at VCRM wiring harness connector. If both readings are less than 5 ohms, go to next step. If either reading is 5 ohms or greater, locate and repair open in Light Blue wire between VCRM 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. Check resistance between ground circuit (Black wire) and Power-To-Cooling Fan circuit (Light Blue wire) at cooling fan motor connector. If resistance is less than 10 ohms, replace VCRM. Reconnect all components and repeat QUICK TEST. If resistance is 10 ohms or greater, replace cooling fan motor. Reconnect all components and 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 VCRM connector. Clean or repair connector as necessary. Turn ignition on. Check 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 VCRM. Reconnect all components and repeat QUICK TEST. If voltage is one volt or greater, 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 60). No test procedures have been omitted.

  13. 60) KOEO/KOER Code P1625 &/Or Code P1626

    Code P1625 indicates that B + to VCRM fan circuit is not detected. Code P1626 indicates that B + to VCRM A/C circuit is not detected. Testing for both codes is the same. Possible causes for this fault are:
    • Open B + circuit to VCRM terminals No. 4 and 5.
    • Faulty VCRM.

    Turn ignition off. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Check voltage between negative battery terminal and terminals No. 4 (Yellow wire) and No. 5 (Yellow wire) at VCRM wiring harness connector. If both readings are greater than 10.5 volts, replace VCRM. Reconnect all components and repeat QUICK TEST. If either reading is 10.5 volts or less, check cooling fan related fuses. If fuses are okay, locate and repair open in B + circuit. If fuse is 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.

  14. 65) Continuous Memory Code P1625 &/Or Code P1626

    Continuous Memory Code P1625 indicates that an open B (+) supply to VCRM fan circuit has been detected. Continuous Memory Code P1626 indicates that an open B + supply to VCRM A/C circuit has been detected. Testing for both codes is the same. Possible cause for this fault is:
    • Intermittent open B + circuit to VCRM terminals No. 4 and 5.

    Turn ignition off. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Connect a non-powered test light between ground and terminal No. 5 (Yellow wire) at VCRM 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 VCRM 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.
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