Diagnostic trouble code (DTC) information ECM-640F

Condition 

The engine control module (ECM) checks that the camshaft is in the correct position in relation to the position of the crankshaft. If the camshaft position is incorrect, the control module will adjust the adaptation for the camshaft position. The diagnostic trouble code (DTC) is stored if the adaptation is too great.

The diagnostic is active when the engine is running, engine at operating temperature.

Substitute Value 

• None.

Possible Source 

Signal too high 

• Poor oil quality
• The timing gear belt has jumped off the cogs
• Incorrectly adjusted camshafts
• Damaged reset valve
• Mechanical fault in the variable valve timing (VVT) unit.

Signal too low 

• Poor oil quality
• The timing gear belt has jumped off the cogs
• Incorrectly adjusted camshafts.

Fault symptom[s] 

• Uneven idle
• Increased emissions
• The engine cuts out when driving.