NA7 - Check IDM Circuit For Short to Ground

NOTE: During this check when 4-wire Heated Oxygen Sensor (HO2S) is connected to the vehicle harness on Distributor Ignition (DI) vehicles, a short to SIG RTN (Pin 46) may be indicated in conjunction with an actual PWR GND short.

- Key "OFF".

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

- Ignition Control Module (ICM) disconnected.

- Scan tool disconnected from Data Link connector.

- Ignition coil disconnected on non-Computer Control Dwell (CCD) vehicles.

- Measure resistance between test pin 4 and test pins 20, 40, 46 and 60 at the breakout box.

- Is each resistance above 10,000 ohms?

Yes -- Reconnect Scan Tool. Go to NA8. NA8 - Check ICM

No -- Remove breakout box. Service short to ground in Ignition Diagnostic Monitor (IDM) circuit. Reconnect all components. Clear continuous memory. Clearing Diagnostic Trouble Codes

Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)