XB4 - Check PCM Power Ground Circuits

- Key "OFF".

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

- Measure resistance between the negative battery post, and test pins 40 and 60 at the breakout box.

- Is resistance less than 5.0 ohms?

Yes -- Go to XB5. XB5 - Check Internal PCM Ground Circuits

No -- Service open PWR GND circuit. Remove breakout box, reconnect PCM. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)