Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information

Condition
Diagnostic trouble code (DTC) ECM- 4D is stored if the control module registers misfiring of such severity that the three-way catalytic converter (TWC) will be damaged.

Substitute value
- Fuel trim disabled.
- Three-way catalytic converter (TWC) diagnostic disabled.
- Knock retardation disabled.
- Idle air trim adaptation is disabled.
- Evaporative emission (EVAP) system operates at minimum.
- Altitude compensation disabled.

Possible source
- Fuel stoppage.
- Repeated cold starting where the engine coolant temperature (ECT) has not reached normal operating temperature between starts.
- Water in spark plug wells.
- Defective spark plugs, ignition cables, distributor cap, rotor, ignition coil or flywheel / pulse wheel.
- Contaminated fuel or incorrect fuel type.
- Blocked / leaking injector.
- Intermittent open-circuit, intermittent short-circuit to ground, intermittent short-circuit to voltage supply, contact resistance or loose connection in the ignition system low-tension side, in the injector circuit or fuel pump (FP) circuit.
- Blocked crankcase ventilation.
- Damaged VVT-unit.
- Moisture, flashover in the ignition system on HT side.
- Leakage between cooling system and cylinder.
- Uneven compression.

Fault symptom[s]
- Engine difficult to start.
- The engine runs unevenly at idle or there are marked jerks in engine response when driving.
- Poor performance.
- High emissions.