Diagnostic trouble code (DTC) information

Condition 

Fig 1: Identifying Engine Speed Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

The control module calculates the number of teeth when the starter motor operates. The higher the engine speed (RPM), the higher the number of teeth that are allowed to be missed. Diagnostic trouble code (DTC) ECM-3100 is stored if control module registers a deviation in the number of teeth.

Substitute Value 

Uses the camshaft position (CMP) sensor if it functions.

Possible Source 

Intermittent fault 

• open-circuit in the signal cable
• short-circuit to ground in the signal cable
• short-circuit to supply voltage in the signal cable
• defective engine speed (RPM) sensor
• intermittent open-circuit.

Fault symptom[s] 

None.