Engine-CodesGeneric – P0779

P0779 Code - Pressure Control Solenoid 'B' Intermittent

Quick Answer

The P0779 diagnostic trouble code (DTC) indicates an issue with the Pressure Control Solenoid 'B' in the transmission. Common causes include Faulty Pressure Control Solenoid 'B', Wiring or connector issues, Transmission control module malfunction. 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
P0779 indicates Pressure Control Solenoid 'B' Intermittent.
Common causes
Common causes include Faulty Pressure Control Solenoid 'B', Wiring or connector issues, Transmission control module malfunction.
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.
Table of contents Created and updated by William Orellana on Sep 17, 2024
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Code P0779 Description

The P0779 diagnostic trouble code (DTC) indicates an issue with the Pressure Control Solenoid 'B' in the transmission. This solenoid is responsible for regulating the hydraulic pressure within the transmission, which is crucial for proper shifting and overall performance. When this solenoid operates intermittently, it can lead to erratic shifting patterns, harsh shifts, or even transmission slipping. If left unaddressed, it can cause further damage to the transmission system, resulting in costly repairs.

OBDII Code P0779 - Pressure Control Solenoid 'B' Intermittent
P0779 Code - Pressure Control Solenoid 'B' Intermittent

Common Causes of P0779

  1. Faulty Pressure Control Solenoid 'B'
  2. Wiring or connector issues
  3. Transmission control module malfunction
  4. Low transmission fluid levels
  5. Internal transmission damage

Symptoms of P0779

  1. Erratic shifting patterns
  2. Harsh or delayed shifts
  3. Transmission slipping
  4. Decreased fuel efficiency
  5. Illumination of the Check Engine Light

How to Fix P0779

  1. Diagnose the issue by using a scan tool to confirm the P0779 code and perform a visual inspection of the transmission components.
  2. Test the Pressure Control Solenoid 'B' for proper operation and replace it if necessary.
  3. Check the wiring and connectors for any damage or corrosion, repairing or replacing as needed.
  4. Inspect the transmission control module for faults and reprogram or replace it if required.
  5. Perform a transmission fluid flush and fill to ensure proper levels and quality.

Cost to Fix P0779

The typical repair costs for addressing a Pressure Control Solenoid 'B' Intermittent issue can range from $200 to $600, including parts and labor. However, it's important to note that specific diagnosis time and labor rates at auto repair shops can vary significantly based on factors such as location, vehicle make and model, and engine type. Rates in metropolitan areas or at dealerships may be higher, while independent shops often charge less. It's advisable to obtain local estimates for a more accurate cost assessment.

Tech Notes for P0779

When a transmission solenoid is malfunctioned, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is dirty, it's recommended to change the transmission fluid and if possible removing the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a mechanical transmission failure and that the transmission will need to be rebuilt or replaced.

When is the Code Detected?

Engine Control Module (ECM) detectes an intermittent condition on the solenoid circuit

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Code P0779 Information for Specific Makes

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 P0779 Code

1. What does the OBDII code P0779 mean?

P0779 indicates an intermittent issue with Pressure Control Solenoid 'B,' which is responsible for regulating hydraulic pressure in the transmission.

2. What are the common symptoms of a P0779 code?

Symptoms may include erratic or delayed shifting, transmission slipping, reduced fuel efficiency, and the Check Engine Light being illuminated.

3. What causes the P0779 code to appear?

Common causes include a faulty pressure control solenoid, wiring issues such as damaged or corroded connections, low transmission fluid, or a failing transmission control module (TCM).

4. Can I drive with a P0779 code?

Driving with a P0779 code is not recommended, as it may cause further damage to the transmission or lead to unsafe driving conditions.

5. How is the P0779 code diagnosed?

A mechanic will use a scan tool to confirm the code, inspect the transmission fluid level and condition, check the wiring and connections, and test the functionality of the pressure control solenoid.

6. How do I fix a P0779 code?

Repairs may include replacing the pressure control solenoid, repairing or replacing damaged wiring, flushing the transmission, or updating/replacing the TCM.

7. What does it cost to fix a P0779 code?

Repair costs vary depending on the issue but can range from $150 to $400 for solenoid replacement, while more extensive transmission repairs could cost significantly more.

8. Can low transmission fluid cause a P0779 code?

Yes, low or dirty transmission fluid can cause the solenoid to operate improperly, leading to this code.

9. How can I prevent a P0779 code from occurring?

Regular maintenance, such as checking and replacing transmission fluid and inspecting wiring, can help prevent issues leading to this code.

10. Does a P0779 code always mean the solenoid is bad?

No, it could also be caused by wiring issues, a defective TCM, or even contaminated transmission fluid, so proper diagnosis is essential.

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