Diagnostic Trouble Code (DTC) Information ECM-2000

Condition 

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 lower/higher than a certain value.

As soon as the engine is started the temperature is calculated theoretically. The diagnostic trouble code (DTC) (Faulty signal) is stored if the calculated temperature exceeds the engine coolant temperature (ECT) sensor signal.

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 low-speed.

Possible Source 

Signal too high 

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

Signal too low 

• Contact resistance and oxidation in the terminals
• Open-circuit in the signal cable
• Open-circuit in the signal ground cable
• Short-circuit to supply voltage in the signal cable
• Damaged temperature sensor.

Faulty signal 

• Damaged temperature sensor
• Damaged coolant thermostat.

Fault symptom[s] 

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