Diagnostic trouble code (DTC) information ECM-2000

Condition

Fig 1: Identifying Engine Coolant Temperature Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

This diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers a short-circuit to ground or supply voltage or an open-circuit in the engine coolant temperature (ECT) sensor circuit.

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

When starting: The intake air temperature (IAT) is used if no fault has been detected on the intake temperature sensor Otherwise the constant +20 °C is used
After starting: The engine coolant temperature (ECT) is calculated based on a model
The cooling fan runs at low-speed.

Possible Source

Signal too high

Short-circuit to supply voltage in the signal cable
Open-circuit in the signal cable
Damaged engine coolant temperature (ECT) sensor.

Signal too low

Short-circuit to ground in the signal cable
Damaged engine coolant temperature (ECT) sensor.

Fault symptom[s]

Malfunction indicator lamp (MIL) lit
Engine difficult to start when warm
Uneven idle
The engine stops, but only when it is at operating temperature
The engine cooling fan (FC) runs continuously even when the ignition is switched off.