Fault code P0290 – a step-by-step guide to diagnosing and fixing it

Error code P0290 is displayed and the check engine light is on - what does this mean?

The OBD/EOBD system has detected a fault in the injection valve control circuit of cylinder 10. This DTC P0290 indicates a problem with the electrical control or the injection valve itself and can have slightly different interpretations with different manufacturers.

What causes can this error code have?

• Defective injection valve cylinder 10
• Damaged wiring to the injection valve
• Corroded or loose plug connections
• Defective engine control unit (ECU)
• Short circuit in the injection valve circuit
• Broken ground wire
• Overheating of the injection valve
• Dirty or clogged injection valve

What symptoms occur in parallel with fault code P0290?

• Engine running unsteadiness: The engine runs unevenly or jerks, especially at idling speed.
• Loss of power: Noticeable reduction in engine power, especially under load.
• Increased fuel consumption: The engine requires more fuel than usual.
• Starting problems: The vehicle is harder to start or starts with a delay.
• Black smoke: Dark exhaust fumes from the exhaust due to incomplete combustion.

How can the problem with error code P0290 be rectified?

• Repairing error code P0290 requires a systematic approach to identify the cause.
• Replacement of the defective injection valve cylinder 10 with a new or overhauled valve after prior functional testing
• Repair or replacement of the damaged wiring between the ECU and injection valve with subsequent insulation test
• Cleaning and renewal of all plug connections on the injection valve with contact spray and new seals
• Professional cleaning of the clogged injection valve with ultrasound or chemical cleaning agents
• Replacement of the engine control unit after confirmation of the defect by diagnostic device and resistance measurements
• Repair of short circuits in the circuit by insulating damaged cable points and replacing affected cables