P0654

CIRCUIT DESCRIPTION
The PCM creates the engine speed output signal by pulsing the circuit to ground. The PCM pulses the circuit at the same rate as the engine speed signal input. The PCM monitors the voltage on the engine speed output circuit. If the PCM determines the voltage is out of the normal operating range, a DTC sets.

CONDITIONS FOR RUNNING THE DTC
^ The engine speed is greater than 400 RPM.
^ The ignition voltage is greater than 6 volts, but less than 18 volts.

CONDITIONS FOR SETTING THE DTC
^ The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.
^ The above condition exists for a minimum of 5.0 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) does not illuminate.
^ The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A current DTC clears when the diagnostic runs and does not fail.
^ A history DTC clears after 40 consecutive malfunction free warm-up cycles.
^ The PCM receives the clear code command from the scan tool.

TEST

Steps 1-7:

Steps 8-9: