Diagnostic Aids
Perform this test when directed by QUICK TEST. This test is intended to diagnose ECA, Clutch Engage/Interlock Switch, Neutral Drive/Gear Switch and following harness circuits.
- CES
- CIS
- NDS
- NGS
- SIG RTN
1) Code 67/522, 525 Or 528: System Identification - Code 67/522, 525 or 528 indicates voltage is high at test pin No. 10 (A/C input) or 30 (neutral drive) while cranking engine during KOEO SELF-TEST. Possible causes for these faults are as follows.
- A/C Circuit Shorted To Power
- Clutch Engage/Interlock Switch Circuits Open
- Faulty ECA
- Neutral Drive/Gear Switch Circuits Open
- Starter Relay Disconnected During Self-Test
8) Check Neutral Drive Input - Turn ignition off, and wait 10 seconds. Turn A/C off (if equipped). Place transmission in Neutral or Park. Disconnect and inspect ECA 60-pin connector. With breakout box installed, connect ECA. Turn ignition on, leaving engine off. Set DVOM on 20-volt scale. Measure voltage between test pin No. 30 at breakout box and chassis ground. If voltage is greater than one volt, go to next step. If voltage is less than one volt and vehicle is equipped with A/C, go to step 10). If voltage is less than one volt and vehicle is not equipped with A/C, replace ECA.
9) Check Neutral Drive Switch - Turn ignition off, and wait 10 seconds. With breakout box installed, disconnect ECA. Set DVOM on 200-ohm scale. Locate and disconnect vehicle harness connector from neutral drive switch. Measure resistance across neutral drive switch. If resistance is greater than 5 ohms, replace neutral drive switch. Remove breakout box, reconnect all components and rerun QUICK TEST. If resistance is less than 5 ohms, repair open in vehicle harness neutral drive switch circuit. Remove breakout box, reconnect all components and rerun QUICK TEST .
10) Check A/C Input - Turn A/C off. If A/C was on, rerun QUICK TEST . If Code 67, 79, 522, 525 or 528 is present, disconnect and inspect ECA 60-pin connector. With breakout box installed, disconnect ECA. Turn ignition on, leaving engine off. Set DVOM on 20-volt scale. Measure voltage between test pin No. 10 at breakout box and chassis ground. If voltage is greater than one volt, repair short to power in A/C circuit. Remove breakout box, reconnect all components and rerun QUICK TEST . If voltage is less than one volt, replace ECA. Remove breakout box, reconnect all components and rerun QUICK TEST .
11) Check A/C Input Circuit - Turn A/C on. If engine idles low, ECA is not receiving or recognizing A/C input at test pin No. 10. See Fig 2 . Turn ignition off, and wait 10 seconds. Disconnect and inspect ECA 60-pin connector. With breakout box installed, disconnect ECA. Set DVOM on 20-volt scale. Turn ignition on, leaving engine off. Turn A/C on. Measure voltage between test pins No. 10 and 40. If voltage is greater than 10.5 volts, replace ECA. Remove breakout box, reconnect all components and rerun QUICK TEST . If voltage is less than 10.5 volts, repair open in A/C circuit. Remove breakout box, reconnect all components and rerun QUICK TEST .