OBD-II Trouble Code Description for P0654 GMC

Engine RPM Output Circuit

What does this mean?

OBD2 Code P0654 GM definition:
The Instrument Panel Cluster (IPC) supplies a voltage to the Engine Speed Output circuit. The PCM creates the Engine Speed Output signal by rapidly grounding this circuit via an internal switch called a driver. The other components on this circuit recognize the voltage being pulled to ground as an indication of engine speed. The driver supplies the ground for the component being controlled. Each driver has a fault line which the PCM monitors. When the PCM commands a component ON, the voltage of the control circuit should be low (near 0 volts). When the PCM commands the control circuit to a component OFF, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the fault line status changes causing the DTC to set.

Symptoms

Possible sumptoms of OBD code P0654 GM
– Engine Light ON (or Service Engine Soon Warning Light)

Causes

Possible causes of OBD code P0654 GM
– Open or short speed output circuit circuit – Poor speed output circuit electrical connection – Instrument cluster faulty – Faulty PCM

Possible Solutions