Fault-Code Library

The ECU sees the crankshaft and camshaft signals outside their expected relationship.

Measured fuel pressure fell below the pressure requested by the engine controller.

Airflow reported by the MAF sensor does not agree with the ECU's calculated operating conditions.

Fuel trim has reached a lean threshold because the ECU is adding more fuel than expected.

Boost pressure exceeded the ECU's permitted target for the operating condition.

The engine did not produce the boost pressure requested by the controller.

Misfires are occurring across more than one cylinder or without one consistent cylinder pattern.

Measured or inferred EGR flow is lower than the controller expects.

Upstream and downstream oxygen-sensor behavior suggests insufficient catalyst oxygen-storage performance.

The ECU calculates that particulate-filter performance is below its required threshold.

The intake-runner position signal is outside the range expected by the controller.

The SCR system is not reducing NOx emissions as effectively as the ECU expects.

A NOx sensor signal or its controller behavior is outside the expected operating range.

The pressure signal used to calculate DPF restriction is implausible or outside range.

Calculated soot loading has reached a level that requires diagnosis before normal operation can continue.

One or more modules stopped receiving expected messages from the engine controller.