X3 - Ground Fault Isolation
- Key "OFF".
- Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires etc. Service as necessary.
- Install breakout box and connect PCM to breakout box.
- Key "ON", engine "OFF".
- Measure voltage between battery negative post and test pins 40 and 60 at the breakout box.
- Is each voltage less than 0.5 volt?
Yes -- Go to X4. X4 - PCM Ground Fault Isolation
No -- Service open ground circuit. Remove breakout box. Reconnect PCM. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)