DTC 1-4-4

1-4-4 LOAD SIGNAL

Condition(s) for DTC
^ The timing varies with the load signal from the ICM. The DTC is recorded if the signal remains continuously high or low for 20 ignitions.

Substitute value
^ The load signal is set to the full-load value at speeds above idling.
^ The engine cooling fan will continue to run for 6 minutes.

Fault source(s)
^ Signal too high:
- Open-circuit in signal lead.
- Signal lead short-circuited to supply.
- Contact resistance in connections.

^ Signal too low:
- Signal lead short-circuited to ground.

Fault symptom(s)
^ Post-running of engine cooling fan.

TESTING PROCEDURE





Status message
^ Check current Status Message.

If Status message is: Permanent fault, signal too high:
- Proceed to: PERMANENT FAULT, SIGNAL TOO HIGH Section below.
If Status message is: Permanent fault, signal too low:
- Proceed to: PERMANENT FAULT, SIGNAL TOO LOW Section below.
If Status message is: Intermittent fault, signal too high:
- Proceed to: INTERMITTENT FAULT, SIGNAL TOO HIGH Section below.
If Status message is: Intermittent fault, signal too low:
- Proceed to: INTERMITTENT FAULT, SIGNAL TOO LOW Section below.

^ The fault counter indicates the number of starts during which the ICM has detected a fault-free signal after the DTC has been recorded.





PERMANENT FAULT, SIGNAL TOO HIGH

Checking load signal to ICM
^ Disconnect engine cooling fan.
^ Connect test box to DI system and check ground terminals.
^ Plug ICM into test box adapter.
^ START engine and run up to working temperature.
^ Connect voltmeter across #42 (ICM B12) and #29 (ICM A29) on test box.

Instrument should indicate 50 - 100 mV.
Reading should increase with speed.

If reading is correct:
- Check load signal.
If instrument indicates battery voltage:
- Check lead between MFI B12 and ICM B12 for short-circuit to supply.

^ On automatics, also check lead connected to TCM B12 for short-circuit to supply.

If instrument indicates approx. 0 Volts:
- Check lead between MFI B12 and ICM B12 for open-circuit.





Checking load signal
^ Switch OFF ignition.
^ Disconnect test box.
^ Reconnect ICM.
^ START engine.
^ Erase DTC.
^ Allow engine to idle.

If DI DTC 1-4-4 is not recorded:
- DTC is due to poor connection in control module connector.
- Check connector for contact resistance and oxidation.
If DI DTC 1-4-4 is recorded:
- Try with new ICM.





PERMANENT FAULT, SIGNAL TOO LOW

Checking signal lead
^ Check lead between MFI B12 and ICM B12 for short-circuit to ground.
^ On automatics, also check lead connected to TCM B12 for short-circuit to ground.

INTERMITTENT FAULT, SIGNAL TOO HIGH





Checking wiring and connections
^ Check connections to ICM B12 and MFI B12 for loose connections, and for contact resistance and oxidation.
^ Check lead between ICM B12 and MFI B12 for intermittent open-circuit.
^ Check lead between ICM B12 and MFI B12 for intermittent short-circuit to supply.
^ On automatics, also check lead connected to TCM B12 for intermittent short-circuit to supply.

INTERMITTENT FAULT, SIGNAL TOO LOW





Checking wiring
^ Check lead between ICM B12 and MFI B12 for intermittent short-circuit to ground.
^ On automatics, also check lead connected to TCM B12 for intermittent short-circuit to ground.