Diagnostic Aids

KAPWR is interrupted when PCM or battery is disconnected. DTC P0603 or P1605 may be generated during the next PCM power-up.

Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:

Fig 1: Keep Alive Power (KAPWR) Circuit Schematic

1) DTC P0603 Or P1605: Check Battery Terminals

Inspect battery terminals for corrosion or loose connection. Service as necessary. If battery terminals are okay, go to next step.

2) Check Wiring Harness

Inspect wiring harness and connectors for damage or corrosion. Ensure wiring harness is not improperly routed too close to ignition or exhaust components. Service as necessary. If no problems are found, go to next step.

3) Check KAPWR Circuit

Turn ignition off. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Connect DVOM between test pin No. 55 (KAPWR) at breakout box and chassis ground. While observing DVOM, wiggle and bend small sections of wiring harness between PCM and dash panel. If voltage is continuously 10.5 volts or more, go to next step. If at anytime, voltage drops to less than 10.5 volts, isolate open in KAPWR circuit and repair as necessary.

4) Check For DTC P0603 & P1605

Perform KOEO ON-DEMAND SELF-TEST . If DTC P0603 or P1605 is present, replace PCM. If any other DTCs are present, service as necessary. If no DTCs are present, testing is complete. DTC P0603 or P1605 may have been due to a previous repair.