AutoCodes – Chevrolet – P0878 2017 Chevrolet Silverado

P0878 2017 Chevrolet Silverado Code - Transmission Fluid Pressure Switch 4 Circuit High Voltage

Quick Answer

The Transmission Fluid Pressure (TFP) switch 4 is part of the Transmission Control Solenoid Valve Assembly which has no serviceable parts. Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Transmission Control Solenoid Valve Assembly. 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 2017 Chevrolet Silverado indicates Transmission Fluid Pressure Switch 4 Circuit High Voltage.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Transmission Control Solenoid Valve Assembly.
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 393

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 Aug 03, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0878 2017 Chevrolet Silverado Description

The Transmission Fluid Pressure (TFP) switch 4 is part of the Transmission Control Solenoid Valve Assembly which has no serviceable parts. The Transmission Control Module (TCM) supplies a signal circuit to the TFP switch 4. The TFP switch 4 has an internal case ground. TFP switch 4 is normally closed or LOW. When oil pressure is present at the TFP switch 4, the switch is open or HIGH. The normal LOW pressure control solenoid 5 controls pressure to the 1-2-3-4 clutch regulator valve. The TCM monitors the TFP switch 4 to determine the position of the 1-2-3-4 clutch regulator valve. When the 1-2-3-4 clutch is commanded OFF, pressure is present on the TFP switch 4. When the 1-2-3-4 clutch is commanded ON, the 1-2-3-4 clutch regulator valve moves and pressure to the TFP switch 4 is exhausted through the 1-2-3-4 clutch regulator valve. The Diagnostic Trouble Code (DTC) will be set when the TCM detects that the TFP switch 4 signal voltage remains HIGH after the 1-2-3-4 clutch transitions from a LOW pressure state to a HIGH pressure state. The TCM counts each incident. The DTC sets when 8 counts are accumulated.

OBDII Code P0878 2017 Chevrolet Silverado - Transmission Fluid Pressure Switch 4 Circuit High Voltage - AutoCodes.com — P0878 2017 Chevrolet Silverado Code - Transmission Fluid Pressure Switch 4 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0878 2017 Chevrolet Silverado?

Low transmission fluid level
Dirty transmission fluid
Faulty Transmission Control Solenoid Valve Assembly
Transmission Control Solenoid Valve Assembly harness is open or shorted
Transmission Control Solenoid Valve Assembly circuit poor electrical connection

How to Fix the DTC P0878 2017 Chevrolet Silverado?

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 2017 Chevrolet Silverado 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 2017 Chevrolet Silverado code?

Need more information on how to fix the P0878 2017 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

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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.

Frequently Asked Questions about P0878 2017 Chevrolet Silverado Code

1. What does the OBDII code P0878 mean for a 2017 Chevrolet Silverado?

P0878 indicates a high voltage issue in the Transmission Fluid Pressure Switch 4 Circuit, which monitors hydraulic pressure in the transmission.

2. What are the common symptoms of code P0878 in a 2017 Chevrolet Silverado?

Symptoms may include harsh or erratic shifting, the transmission going into limp mode, decreased fuel efficiency, or the check engine light being illuminated.

3. What causes the P0878 code to appear in a 2017 Chevrolet Silverado?

Common causes include a faulty pressure switch, wiring issues (such as damaged or shorted wires), a malfunctioning transmission control module (TCM), or low/contaminated transmission fluid.

4. Can low transmission fluid cause the P0878 code?

Yes, insufficient fluid levels or contaminated fluid can cause abnormal pressure readings, which may trigger the code.

5. How do you diagnose the P0878 code in a 2017 Chevrolet Silverado?

Diagnosis involves scanning for codes, visually inspecting wiring and connectors, checking transmission fluid condition and level, and testing the pressure switch and related circuits with a multimeter.

6. Can I drive my 2017 Chevrolet Silverado with the P0878 code?

Driving with this code is not recommended, as it can lead to further damage to the transmission and cause unsafe driving conditions.

7. How is the P0878 code fixed in a 2017 Chevrolet Silverado?

Repairs may include replacing the faulty pressure switch, repairing or replacing damaged wiring, cleaning or replacing transmission fluid, or reprogramming or replacing the TCM if necessary.

8. How much does it cost to fix the P0878 code on a 2017 Chevrolet Silverado?

Repair costs vary but typically range from $150 to $500 depending on whether only a pressure switch or wiring repair is needed, or if the TCM or other major components require replacement.

9. Can a software update fix the P0878 code?

In some cases, a TCM software update may resolve the issue if it is caused by a programming error. However, mechanical or electrical faults must be repaired first.

10. How can I prevent the P0878 code from occurring again?

Regular maintenance, including checking and changing transmission fluid as recommended, inspecting wiring for damage, and addressing shifting issues promptly, can help prevent recurrence.