Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information 641A

Condition




The engine control module (ECM) checks that control of the exhaust camshaft is rapid enough by measuring the time taken to deploy the camshaft to the requested angle.
The diagnostic trouble code (DTC) is stored if the engine control module (ECM) detects that deployment of the camshaft is too slow (signal too high) or to slow when the camshaft returns (signal too low).
The diagnostic trouble code (DTC) can be diagnosed by the engine control module (ECM) when the engine coolant temperature (ECT) is above a certain value, the engine is running at least at idle speed and when camshaft control is active.

Substitute value
- None.

Possible source

Signal too high
- Poor oil quality
- Damaged camshaft reset valve
- Mechanical fault in the variable valve timing (VVT) unit.

Signal too low
- Short-circuit to supply voltage in the signal cable
- Poor engine oil quality
- Damaged camshaft reset valve
- Mechanical fault in the variable valve timing (VVT) unit.

Fault symptom[s]
- Malfunction indicator lamp (MIL) lit
- High emissions
- The engine cuts out when driving.