P0877 moderate

Transmission Fluid Pressure Sensor/Switch D Circuit Low

The P0877 code means the vehicle's onboard diagnostic system has detected: Transmission Fluid Pressure Sensor/Switch D Circuit Low. This is a moderate severity code.

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Keep driving?: Short distances only
DIY difficulty: hard
Estimated cost: $100 - $500 (parts and labor)

Check Your Fluid First

ANCEL AD310 OBD-II Scanner

Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.

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Read Transmission Codes

LAUNCH CRP123X (Reads All Systems)

Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.

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Common Symptoms

Check Engine Light illuminated
Slipping during specific gear changes
Delayed engagement in certain gears
Transmission may limit gear range

Probable Causes (Ranked by Likelihood)

Short to ground in pressure sensor D signal wire Very High
Faulty pressure sensor D producing low voltage High
Corroded connector at sensor D Moderate
Low transmission fluid level Moderate

Step-by-Step Diagnostic Procedure

Check transmission fluid level first
Measure voltage at pressure sensor D connector
Test for short to ground in the signal wire
Replace sensor D if wiring and fluid are confirmed good

Frequently Asked Questions

Can I check the fluid level myself?

Many modern vehicles no longer have a traditional dipstick. Check your owner's manual for the correct fluid level check procedure, which may require a scan tool on some models.

Is sensor D in a hard-to-reach location?

Sensor D location varies by transmission. On some models it is externally accessible, while on others it may require removing the transmission pan or valve body.

Can a leak at the sensor cause P0877?

A leak at the sensor seal can lower local pressure and also allow fluid to reach the connector, potentially causing a short. Inspect the area around the sensor for wetness.