Diesel Data: Automotive Repair

P0725

P0725 - Engine Speed Input Circuit Malfunction


Flow Chart





Description
The engine speed is detected as pulsing signals. The signals are sent to the transmission control module (TCM) and are used to control transmission shift. The TCM detects a signal dropout as a malfunction which occurs by an open or a short to ground. If the signal dropout is detected while the vehicle is being accelerated decelerated, a malfunction is detected and a DTC is stored.

Wiring Schematic





Enabling Conditions and Monitor





Driving Pattern




1. Start the engine and accelerate to a speed of 25 mph (40 km/h) or more in D4 or D3 position.
2. Decelerate to a speed of 0 mph (0 km/h) with the throttle valve fully closed.
- If you have difficulty duplicating the DTC, retest after turning off electrical components such as the audio system and the A/C.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.


Diagnosis Details

Conditions for Illuminating the MIL
When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored.

Conditions for Clearing the MIL
The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.