Advanced Diagnostics

DTC P0872: Short in 4th Clutch Transmission Fluid Pressure Switch Circuit, or 4th Clutch Transmission Fluid Pressure Switch Stuck ON




General Description
The 4th clutch transmission fluid pressure switch is installed in the hydraulic pressure circuit to the 4th clutch. When hydraulic pressure is supplied to the 4th clutch, the switch is turned ON. When hydraulic pressure is not supplied to the 4th clutch, the switch is turned OFF. The signal from the 4th clutch transmission fluid pressure switch is input to the powertrain control module (PCM). The PCM detects the hydraulic pressure supply conditions at the gear change to 4th gear (3rd -> 4th, 5th -> 4th) to reduce the shock that occurs at the gear change.

If the 4th clutch transmission fluid pressure switch is ON while driving, and the speed ratio of the output shaft (countershaft) to input shaft (mainshaft) is other than 4th gear (the ratio is Neutral or 5th), the PCM detects a 4th clutch transmission fluid pressure switch failure and stores DTC.




Monitor Execution, Sequence, Duration, DTC Type, OBD Status




Enable Conditions

Malfunction Threshold
The 4th clutch transmission fluid pressure switch input signal is low when driving in 5th gear.

Driving Pattern
Start the engine, and drive the vehicle in the D position and 5th gear for at least 2 seconds.

- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for illuminating the indicator
When a malfunction is detected, the D indicator blinks, and the DTC and the freeze frame data are stored in the PCM memory. The MIL does not come on.

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