Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information ECM-640A

Condition




The engine control module (ECM) checks that control of the intake 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 is diagnosed by engine control module (ECM) when the engine is warm and engine speed is higher than 1300 rpm.

Substitute value
None.

Possible source

Signal too high
- Short-circuit to supply voltage in the signal cable.
- Open circuit on cable harness to VVT-unit.
- Poor oil quality
- Oil level too low.
- VVT-unit tightened with too high torque against camshaft.
- Damaged camshaft reset valve
- Mechanical fault in the variable valve timing (VVT) unit.

Signal too low
- The signal cable is short-circuited to ground.
- Poor engine oil quality
- Damaged camshaft reset valve
- VVT-unit tightened with too high torque against camshaft.
- 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.