DTC 1-1-2 Fault In ECM
1-1-2 FAULT IN ECMConditions for DTCs
^ If the control module detects a fault in the ROM/EPROM or RAM memory circuits, the circuit for the Engine Control Module's (ECM) temperature sensor, knock control circuit (zero test, short term fuel trim test) or Engine Coolant Temperature Sensor (ECT) circuit's NTC coupling, DTC 1-1-2 is set.
Substitute values
^ Fault in the ROM/EPROM memory circuit, RAM circuit or circuit for the ECM temperature sensor:
- No substitute value.
- Temperature sensor, fan 1/2 speed
^ Fault in knock control circuit (zero test, short term fuel trim test):
- Dwell angle reduced for safety reasons.
^ Fault in ECT sensor circuit's NTC coupling:
- At start, assumes a substitute value of +20°C (68°F): some time after start-up, the assumed value is +83°C (181°F).
- Engine cooling fan starts at half speed.
- Idle air trim inhibited.
- Long term fuel trim inhibited.
Fault sources
^ Fault in ECM's ROM/EPROM or RAM circuits.
^ Fault in ECM's circuit for ECM temperature sensor.
^ Fault in ECM's knock control circuit.
^ Fault in ECM's circuit for ECT sensor (NTC coupling).
Fault Symptom
^ A fault in the knock control circuit will lead to impaired performance from initial charge pressure limit.