Diagnostic trouble code (DTC) information

Condition

Fig 1: Identifying Engine Coolant Temperature (ECT) Sensor Connector Terminals

Courtesy of VOLVO CARS OF NORTH AMERICA.

Diagnostic trouble code (DTC) ECM-15 is stored if the engine coolant temperature (ECT) sensor circuit is short-circuited to ground or voltage or if there is an open-circuit in the circuit.

Substitute Value

The engine coolant temperature (ECT) is calculated theoretically after start
Initial boost pressure
The A/C is switched off
No heated oxygen sensor (HO2S) diagnostics
No idle air trim adaptation
No leak diagnostic.

Possible Source

Signal too high:

Short-circuit to supply voltage in the signal cable
Open-circuit in the signal cable or ground lead
Faulty engine coolant temperature (ECT) sensor
Contact resistance and oxidation.

Signal too low:

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

Fault symptom[s]

Difficult to start
The engine cooling fan (FC) operates constantly
Low idling speed
High idling speed
Malfunction indicator lamp (MIL) lit.