Engine Speed Sensor (Camshaft) Error – Data Erratic, Intermittent, or Incorrect
|Fault Code: 778
Engine Speed Sensor (Camshaft) Error – Data Erratic, Intermittent, or Incorrect. The ECM has detected an error in the camshaft position sensor signal.
Possible poor starting. Engine power derate.
Camshaft Engine Position Sensor Circuit
The camshaft engine position sensor provides engine position information to the electronic control module (ECM). The sensor is powered by (+) 5-VDC. The sensor generates the signal by sensing the movement of target teeth machined into a tone wheel that is mounted to the camshaft.
The camshaft position sensor is located below the fuel pump in the back of the gear housing.
This fault is recorded when the ECM does not receive a signal from the camshaft position sensor or the signal the ECM receives is degraded.
Possible causes of this fault code include:
- Open circuit on the supply, signal, or return circuits in the sensor, engine harness, or ECM
- Short circuits to ground or return circuits in the sensor, engine harness, or ECM
- Short circuits to voltage source in the sensor, engine harness, or ECM.
INSITE™ electronic service tool monitor parameters associated with this fault code and sensor include:
- Camshaft engine position sensor state
- Damage to the sensor target teeth or tone wheel.
If this fault code occurs intermittently, look closely for causes of intermittent harness connections such as loose or worn pins in the engine harness connectors.
If this fault code occurs intermittently, Fault Code 2322 will also be active or have high counts.