Diagnostic Trouble Code (DTC) Information

ECM-640A CAMSHAFT RESET VALVE
DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION




Condition
When the engine coolant temperature (ECT) is above 80°C and the engine has been running for more than 2 minutes check the engine control module (ECM) camshaft adaptation ACTUAL and DESIRED values. If these values deviate too much (approximately 10 crankshaft ° for longer than 15 seconds) during "even" driving the engine control module (ECM) interprets it as a fault and diagnostic trouble code (DTC) ECM-640A is stored.

Substitute value
- none

Possible source

Incorrect signal
- camshaft belt has jumped out of place on the cogs
- low oil pressure/bad oil quality
- defective reset valve
- mechanical fault in the Variable valve timing (VVT) unit

Fault symptom[s]
- uneven idle
- increased emissions