Diagnostic trouble code (DTC) information

WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.

Condition

Fig 1: Identifying Engine Coolant Temperature (ECT) Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

Diagnostic trouble code (DTC) ECM-A0 is stored if the control module detects rapid changes in the engine coolant temperature (ECT).

Substitute Value

No fuel trim
Limited EVAP control
No three-way catalytic converter (TWC) diagnostic.

Possible Source

Defective engine coolant temperature (ECT) sensor
Contact resistance in the terminals.

Fault symptom[s]

Malfunction indicator lamp (MIL) lit
High fuel consumption.