DTC ECM-640A
Condition
When the engine coolant temperature (ECT) is above 80 degrees 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 degrees 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.