Diagnostic Aids
Perform this test only when directed by TEST C, TEST J or TEST P. This test is intended to diagnose ECA, EEC power relay, battery voltage and following harness circuits.
- Ignition Switch
- KAPWR
- PWR GND
- SIG RTN
- VPWR
To prevent replacement of good components, be aware that following non-EEC related areas and components may be cause of problem.
- Alternator
- Battery Cables
- Ground Straps
- Ignition Switch
- Voltage Regulator
1) Battery Voltage Check - Turn ignition on, leaving engine off. Set DVOM on 20-volt scale. Measure voltage across battery terminals. If voltage is more than 10.5 volts, go to next step; if it is less than 10.5 volts, service or replace discharged battery.
2) Check Continuity Of PWR GND - Circuit Turn ignition off. Wait 10 seconds. Disconnect and inspect ECA 60-pin connector. With breakout box installed, connect ECA to breakout box. Set DVOM on 200-ohm scale. Measure resistance between test pins No. 40 and 60 at breakout box and negative battery post. If all readings are less than 5 ohms, go to next step. If any reading is more than 5 ohms, repair open in PWR GND circuit. Remove breakout box, reconnect ECA and rerun QUICK TEST .
3) Check For Open Between SIG RTN & PWR GND Circuits At ECA. - Turn ignition off, and wait 10 seconds. With breakout box installed, connect ECA. Set ohmmeter on 200-ohm scale. Measure resistance between test pin No. 46 and test pins No. 40 and 60 at breakout box. If all resistance readings are less than 5 ohms, go to next step. If any resistance reading is greater than 5 ohms, replace ECA. Remove breakout box, and rerun QUICK TEST .
4) Check Continuity Of SIG RTN Circuit - Turn ignition off. Wait 10 seconds. With breakout box installed, connect ECA. Set ohmmeter on 200-ohm scale. Measure resistance between test pin No. 46 at breakout box and SIG RTN circuit at self-test connector. If resistance is less than 5 ohms, remove breakout box, reconnect ECA and go to next step. If resistance is greater than 5 ohms, repair open in SIG RTN circuit. Remove breakout box, reconnect ECA and rerun QUICK TEST.
5) Check KAPWR Circuit Voltage At EEC Power Relay - Turn ignition off. Remove EEC power relay. Turn ignition on, leaving engine off. Set DVOM on 20-volt scale. Measure voltage between KAPWR circuit at EEC power relay harness connector and battery negative post. If voltage is greater than 10.5 volts, go to next step. If voltage is less than 10.5 volts, repair open in KAPWR circuit between EEC power relay and battery positive post. Reconnect all components, and rerun QUICK TEST .
6) Check Ignition Circuit Voltage At EEC Power Relay - Turn ignition on, leaving engine off. Remove EEC power relay. Set DVOM on 20-volt scale. Measure voltage between ignition switch circuit at EEC power relay vehicle harness connector and battery negative post. If voltage is greater than 10.5 volts, go to next step. If voltage is less than 10.5 volts, repair open in ignition switch circuits. Reconnect all components, and rerun QUICK TEST .
7) Check PWR GND Circuit Continuity - Turn ignition off, and wait 10 seconds. Disconnect ECA. Set DVOM on 200-ohm scale. Measure resistance between PWR GND circuit at EEC power relay vehicle harness connector and battery negative post. If resistance is less than 10 ohms, go to next step. If resistance is greater than 10 ohms, repair open in circuit. Reconnect ECA, and rerun QUICK TEST .
8) Check Continuity Of VPWR Circuit - Turn ignition off. With breakout box installed, connect ECA. Remove EEC power relay. Measure resistance between pins No. 37 and 57 at breakout box and VPWR circuit at EEC power relay harness connector. If all readings are less than 5 ohms, go to next step. If any reading is more than 5 ohms, repair open in VPWR circuit between EEC power relay and ECA. Remove breakout box, reconnect all components and rerun QUICK TEST .
9) Check VPWR Circuit At EEC Power Relay - Turn ignition off. With breakout box installed, connect ECA. Install EEC power relay. Turn ignition on, leaving engine off. Set DVOM on 20-volt scale. Measure voltage between test pins No. 37 and 57 and pins No. 40 and 60 at breakout box. If any reading is greater than 10.5 volts, repair open or short to ground in VPWR circuit between ECA and EEC power relay. Remove breakout box, and rerun QUICK TEST . If any reading is less than 10.5 volts, replace EEC power relay. Remove breakout box, and rerun QUICK TEST .