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.