P0654
DTC P0654
CIRCUIT DESCRIPTION
The engine control module (ECM) creates the engine speed signal by pulsing the circuit to ground. The ECM monitors the voltage on the engine speed signal circuit. If the ECM determines that the voltage is not within the normal operating range, the ECM sets a DTC.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0654 Engine Speed Output Circuit
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 ECM detects that the commanded state of the driver and the actual state of the signal circuit do not match.
- The above condition exists for a minimum of 5 seconds.
ACTION TAKEN WHEN THE DTC SETS
- The ECM stores the DTC information in memory when the diagnostic test runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The ECM records the operating conditions at the time when the diagnostic test fails. The ECM stores this information in the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
- The DTC becomes history when the conditions for setting the DTC are no longer present.
- A history DTC is cleared after 40 consecutive malfunction free warm-up cycles.
- The ECM receives the clear code command from the scan tool.
TEST
