Operation CHARM: Car repair manuals for everyone.

X4 - PCM Ground Fault Isolation



- Key "OFF".

- Breakout box installed, Powertrain Control Module (PCM) connected.

- Measure resistance between test pin 46 and test pins 40 and 60 at the breakout box.

- Is each resistance less than 5.0 ohms?

Yes -- Go to X5. X5 - Check SIG RTN Circuit Continuity

No -- Replace PCM. Remove breakout box. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)