AutoCodes – Generic – P179C

P179C Code - Main Pressure Valve Electric Fault

Quick Answer

The Engine Control Module (ECM) monitors the Main Pressure Valve. Common causes include Faulty Main Pressure Valve, Main Pressure Valve harness is open or shorted, Main Pressure Valve 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: P179C indicates Main Pressure Valve Electric Fault.
Common causes: Common causes include Faulty Main Pressure Valve, Main Pressure Valve harness is open or shorted, Main Pressure Valve 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 13,953

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 Jan 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P179C Description

The Engine Control Module (ECM) monitors the Main Pressure Valve. The ECM sets the OBDII code when the Main Pressure Valve is not to factory specifications.

OBDII Code P179C - Main Pressure Valve Electric Fault - AutoCodes.com — P179C Code - Main Pressure Valve Electric Fault

What does this mean?

What are the Possible Causes of the DTC P179C?

Faulty Main Pressure Valve
Main Pressure Valve harness is open or shorted
Main Pressure Valve circuit poor electrical connection

How to Fix the DTC P179C?

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 P179C 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 P179C code?

Need more information on how to fix the P179C code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P179C code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P179C Audi — Main Pressure Valve Electric Fault
P179C Buick — Transmission Clutch 1 Slip Adapt
P179C Cadillac — Transmission Clutch 1 Slip Adapt
P179C Chevrolet — Transmission Clutch 1 Slip Adapt
P179C GMC — Transmission Clutch 1 Slip Adapt
P179C Volkswagen — Main Pressure Valve Electric Fault

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 P179C Code

1. What are the common symptoms of OBDII code P179C (Main Pressure Valve Electric Fault)?

When this code is triggered, you may experience harsh shifting, transmission slipping, erratic shifting behavior, and possible transmission overheating.

2. What are some possible causes of OBDII code P179C?

Potential causes include a faulty main pressure valve, wiring issues in the transmission control module, low transmission fluid levels, or a malfunctioning transmission control module.

3. How serious is OBDII code P179C?

This code indicates an issue with the main pressure valve in the transmission, which can lead to transmission performance problems. It is important to address this issue promptly to avoid further damage to the transmission.

4. Can I continue driving with OBDII code P179C active?

It is not recommended to continue driving with this code active, as it can lead to further damage to the transmission. It is best to have the issue diagnosed and repaired as soon as possible.

5. How can I diagnose OBDII code P179C?

Diagnosing this code typically involves using a scan tool to retrieve the code, checking the transmission fluid level and condition, inspecting the wiring and connectors related to the main pressure valve, and performing a thorough transmission system inspection.

6. Is it possible to repair OBDII code P179C on my own?

While some DIY enthusiasts may attempt to address this issue, diagnosing and repairing transmission-related problems can be complex. It is recommended to seek the assistance of a qualified mechanic or technician.

7. How much does it cost to repair OBDII code P179C?

The cost of repairing this code can vary depending on the underlying cause of the issue, labor rates in your area, and the cost of parts. It is advisable to obtain quotes from different repair shops for an accurate estimate.

8. Can a faulty main pressure valve be repaired, or does it need to be replaced?

In most cases, a faulty main pressure valve will need to be replaced rather than repaired. This ensures proper functioning and reliability of the transmission system.

9. Will resetting the OBDII code P179C make it go away permanently?

Simply resetting the code without addressing the underlying issue will not make it go away permanently. The root cause of the problem needs to be diagnosed and repaired to prevent the code from reoccurring.

10. How long does it typically take to repair OBDII code P179C?

The repair time can vary depending on the specific cause of the code and the extent of the repairs needed. It may take a few hours to a full day to diagnose and repair the issue properly.