Diagnostic Trouble Code (DTC) Information ECM-6400

Condition

Fig 1: Identifying Variable Valve Timing (VVT) Unit

Courtesy of VOLVO CARS CORPORATION

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) detects a short-circuit to supply voltage (high signal), short-circuit to ground (low signal) or an open-circuit (signal missing) in the signal circuit between the intake camshaft reset valve and the engine control module (ECM).

The diagnostic trouble code (DTC) can be diagnosed when the engine is running.

Substitute Value

Variable intake camshaft control switched off.

Possible Source

Signal too high

Short-circuit to supply voltage in the signal cable
Damaged (intake) camshaft reset valve.

Signal too low

Short-circuit to ground in the signal cable
Short-circuit to ground in the power supply cable
Contact resistance in the connectors
Damaged (intake) camshaft reset valve.

Signal missing

Open-circuit in the signal cable
Open-circuit in the power supply cable
Damaged (intake) camshaft reset valve.

Fault symptom[s]

Malfunction indicator lamp (MIL) lit
Uneven idle
Deterioration in performance
The engine stops.