Z158

- Disconnect the PCM from the vehicle harness.

NOTE: This erases continuous memory and sets the P1000 DTC.

- Measure the resistance from PIP jack to PWR GND jack.

- Measure the resistance from PIP jack to VPWR jack.

- Is each resistance greater than 10K ohms?

Yes -- SERVICE short in PIP circuit harness.

No -- PCM system failure. REFER to Quick Test for engine control testing. Diagnostic Subroutines (DSR) - Extracting Codes