DTC P0873

DTC P0873: Transmission Fluid Pressure Sensor/Switch C Circuit High

General Description

Courtesy of HONDA, U.S.A., INC.

The reverse clutch pressure sensor uses a strain gauge. The output voltage changes depending on the reverse clutch pressure. The powertrain control module (PCM) sends a 5 V reference voltage to the sensor through a pull-up resistor. When the reverse clutch pressure is low, the sensor resistance decreases and the PCM detects a low signal voltage. Conversely, when the reverse clutch pressure is high, the sensor resistance increases and the PCM detects a high signal voltage. If the reverse clutch pressure sensor signal voltage is a specified voltage for a set time, the PCM detects a malfunction and stores a DTC.

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

Execution	Continuous
Sequence	None
Duration	1 second or more
DTC Type	Two drive cycles, MIL on, A/T gear position indicator blinks
OBD Status	PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions

Condition
Engine start/stop button	ON mode
No active DTCs set (prevents monitor from running)	P0872

Malfunction Threshold

The reverse clutch pressure sensor output voltage [Oil pressure sensor R voltage.] is more than 4.854 V for at least 1 second.

[ ]: HDS Parameter

Possible Cause

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

Reverse clutch pressure sensor PCLR line open (includes connector loose connection or disconnection)
Reverse clutch pressure sensor SG line open (includes connector loose connection or disconnection)
Reverse clutch pressure sensor failure
PCM internal circuit failure

Confirmation Procedure

With the HDS

None.

With the Driving Pattern

Start the engine.
Shift to P position/mode, and wait for at least 1 second.

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC

The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.