Codes P1350/P1361, Ic Circuit: Notes

When engine is cranking, Ignition Control Module (ICM) sends a spark reference and a fuel control signal to PCM. At start of crank, ICM controls ignition timing (module mode). PCM sends a 5 volts signal on by-pass circuit to switch timing to PCM control when the second fuel control pulse is recognized by PCM. Code P1350 will set at start-up is an open is present in ignition control circuit. Code P1361 will set if an open in Ignition Control (IC) circuit, or an open or grounded by-pass circuit is present during time when engine is started. Engine may be started but will run on module mode timing.

Code P1350 will set when the following conditions are present.

• IC circuit opens during engine run mode.

Code P1361 will set when the following conditions are present.

• IC circuit grounded during start-up.

Or 

• PCM not commanding IC mode (open or grounded by-pass circuit) when engine is started.

When Codes P1350/P1361 are set, PCM will remove 5 volts bypass signal causing engine to run on module mode timing. PCM will illuminate Malfunction Indicator Light (MIL).

1. Checks if PCM recognizes a problem. If Codes P1350/P1361 are not set, problem is intermittent and could be caused by a loose connection.
2. With PCM disconnected, ohmmeter reading should be less than 200 ohms, which is the normal resistance of IC circuit through ICM. A higher resistance indicates a fault in IC circuit, a poor ignition module connection, or a faulty ICM.
3. If test light lights when connected between 12 volts and PCM by-pass circuit terminal, then either by-pass circuit is shorted to ground, or ICM is faulty.
4. Checks if ICM switches when by-pass circuit is energized by 12 volts through test light. If ICM switches, ohmmeter reading should shift to greater than 6000 ohms.
5. Disconnecting ICM should make ohmmeter read as if an open circuit was being monitored (infinite reading). Otherwise, IC circuit is shorted to ground.