NB3 - Continuous Codes 212, 222 or 218: Check IDM Circuit

Continuous Memory Diagnostic Trouble Code (DTC) 212 indicates a loss of Ignition Diagnostic Monitor (IDM) input to the Powertrain Control Module (PCM).

Possible causes:

- Open harness circuit.

- Shorted harness circuit.

- Damaged Ignition Control Module (ICM).

- Damaged PCM.

Continuous Memory DTC 222 indicates IDM input to the PCM is always low.

Possible causes:

- Open harness circuit.

- Shorted harness circuit.

- Damaged Crankshaft Position (CKP) or Camshaft Position (CMP) sensor.

- Damaged ICM.

- Damaged PCM.

- B+ low at ICM.

Continuous Memory DTC 218 indicates IDM input to the PCM is always high.

Possible causes:

- Open harness.

- B+ open at secondary coil.

- B+ low at secondary coil.

- Key "OFF", wait 10 seconds.

- Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Disconnect ICM (Pins 7-12).

- Measure resistance between test pin 4 at the breakout box and IDM pin 12 at the ICM vehicle harness connector.

- Is resistance less than 5.0 ohms?

Yes -- Go to NB4. NB4 - Check IDM Circuit For Short to Power (Excluding VREF)

No -- Service open circuit. Remove breakout box. Reconnect PCM. Clear continuous memory. Clearing Diagnostic Trouble Codes

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