AutoCodes – Generic – P0878

P0878 Code - Transmission Fluid Pressure Sensor/Switch 'D' Circuit High

Quick Answer

The Engine Control Module (ECM) monitors the Transmission Fluid Pressure Sensor/Switch 'D'. Common causes include Faulty Transmission Fluid Pressure Sensor/Switch 'D', Transmission Fluid Pressure Sensor/Switch 'D' harness is open or shorted, Transmission Fluid Pressure Sensor/Switch 'D' circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0878 indicates Transmission Fluid Pressure Sensor/Switch 'D' Circuit High.
Common causes: Common causes include Faulty Transmission Fluid Pressure Sensor/Switch 'D', Transmission Fluid Pressure Sensor/Switch 'D' harness is open or shorted, Transmission Fluid Pressure Sensor/Switch 'D' circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 10,976

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 11, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P0878 Description

The Engine Control Module (ECM) monitors the Transmission Fluid Pressure Sensor/Switch 'D'. The ECM sets the OBDII when the Transmission Fluid Pressure Sensor/Switch 'D' is not to factory specifications.

OBDII Code P0878 - Transmission Fluid Pressure Sensor/Switch 'D' Circuit High - AutoCodes.com — P0878 Code - Transmission Fluid Pressure Sensor/Switch 'D' Circuit High

What does this mean?

What are the Possible Causes of the DTC P0878?

Faulty Transmission Fluid Pressure Sensor/Switch 'D'
Transmission Fluid Pressure Sensor/Switch 'D' harness is open or shorted
Transmission Fluid Pressure Sensor/Switch 'D' circuit poor electrical connection

How to Fix the DTC P0878?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0878 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0878 code?

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Need Help with the Code?

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Information for Specific Makes

P0878 Buick — Transmission Fluid Pressure Switch 4 Circuit High Voltage
P0878 Cadillac — Transmission Fluid Pressure Switch 4 Circuit High Voltage
P0878 Chevrolet — Transmission Fluid Pressure Switch 4 Circuit High Voltage
P0878 Dodge — Transmission Fluid Pressure Sensor/Switch 'D' Circuit High
P0878 GMC — Transmission Fluid Pressure Switch 4 Circuit High Voltage
P0878 Toyota — Transmission Fluid Pressure Sensor/Switch 'D' Circuit High

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.