AutoCodes – Audi – P0798 Audi

P0798 Audi Code - Pressure Control Solenoid 'C' Electrical

Quick Answer

The Pressure Control (PC) Solenoid Valve an electronic pressure regulator that controls transmission line pressure based on current flow through its coil windings. Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty pressure control solenoid valve 'C'. 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: P0798 Audi indicates Pressure Control Solenoid 'C' Electrical.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty pressure control solenoid valve 'C'.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 7,766

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 30, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0798 Audi Description

The Pressure Control (PC) Solenoid Valve an electronic pressure regulator that controls transmission line pressure based on current flow through its coil windings. As current flow is increased, the magnetic field produced by the coil moves the solenoid’s plunger further away from the exhaust port. Opening the exhaust port decreases the output fluid pressure regulated by the PC solenoid valve, which ultimately decreases line pressure. The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in response to a signal sent from the Transmission Control Module (TCM).

OBDII Code P0798 Audi - Pressure Control Solenoid 'C' Electrical - AutoCodes.com — P0798 Audi Code - Pressure Control Solenoid 'C' Electrical

What does this mean?

What are the Possible Causes of the DTC P0798 Audi?

Low transmission fluid level
Dirty transmission fluid
Faulty pressure control solenoid valve 'C'
Pressure control solenoid valve 'C' harness is open or shorted
Pressure control solenoid valve 'C' circuit poor electrical connection

How to Fix the DTC P0798 Audi?

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 does this mean?

Code Tech Notes

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.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0798 Audi 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 P0798 Audi code?

Need more information on how to fix the P0798 Audi code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0798 Audi code diagnosed by a professional: Find a repair shop in your area

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 P0798 Audi Code

1. What does the OBDII code P0798 mean on an Audi?

P0798 indicates an electrical issue with the Pressure Control Solenoid 'C' in the transmission, which helps regulate fluid pressure for gear shifting.

2. What are the common symptoms of code P0798 on an Audi?

Symptoms include erratic shifting, slipping gears, harsh or delayed gear changes, and possibly activation of the check engine light.

3. What causes the P0798 code on an Audi?

Common causes include a faulty pressure control solenoid 'C', damaged wiring or connectors, low transmission fluid, or issues with the transmission control module (TCM).

4. How can I diagnose the P0798 code on my Audi?

Use an OBDII scanner to confirm the code, inspect the wiring and connectors for damage, check the transmission fluid level and condition, and test the solenoid for proper operation.

5. Can I drive my Audi with the P0798 code?

Driving with this code is not recommended as it can lead to further transmission damage and unsafe driving conditions due to erratic shifting.

6. How do I fix the P0798 code on an Audi?

Repairs may involve replacing the pressure control solenoid 'C', repairing damaged wiring, refilling or replacing transmission fluid, or reprogramming/repairing the TCM.

7. How much does it cost to repair the P0798 code on an Audi?

Repair costs vary depending on the issue, ranging from $100-$400 for solenoid replacement to higher costs if the TCM or other components need repair.

8. Can low transmission fluid cause the P0798 code on an Audi?

Yes, low or contaminated transmission fluid can affect solenoid operation and trigger this code.

9. How do I prevent the P0798 code from occurring on my Audi?

Regularly maintain your transmission by checking fluid levels, replacing fluid as needed, and inspecting wiring and connectors for wear or damage.

10. Is the P0798 code specific to Audi vehicles?

No, the P0798 code is a generic OBDII code that can appear on various vehicles, but the specific symptoms and repair procedures may vary by make and model.