Diagnostic trouble code (DTC) information ECM-273C

Condition 

Fig 1: Identifying Engine Coolant Temperature (ECT) Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

The engine control module (ECM) checks the signal for engine coolant temperature (ECT).

A diagnostic trouble code (DTC) is stored if the engine control module (ECM) receives a signal from the engine coolant temperature (ECT) sensor corresponding to a temperature that is higher than a certain value.

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

Substitute Value 

• Initial boost pressure
• The engine coolant temperature (ECT) is calculated based on a model. Three-way catalytic converter (TWC) heating and fuel trim at start (starting trim), idle diagnostic and misfire diagnostic are disabled
• The engine cooling fan (FC) runs at a predefined speed.

Possible Source 

• Short-circuit to ground in the signal cable
• Damaged temperature sensor.

Fault symptom[s] 

• Malfunction indicator lamp (MIL) lit
• The engine is difficult to start.