AutoCodes – Generic – P0798

P0798 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 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.

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Code Popularity 22,856

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 Dec 29, 2021

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
Comments
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Code P0798 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 - Pressure Control Solenoid 'C' Electrical - AutoCodes.com — P0798 Code - Pressure Control Solenoid 'C' Electrical

What does this mean?

What are the Possible Causes of the DTC P0798?

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?

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 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.

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Information for Specific Makes

P0798 Acura — Pressure Control Solenoid 'C' Circuit
P0798 Audi — Pressure Control Solenoid 'C' Electrical
P0798 Honda — Pressure Control Solenoid 'C' Circuit
P0798 Lexus — Pressure Control Solenoid 'C' Electrical
P0798 Mercedes-Benz — Pressure Control Solenoid 'C' Electrical
P0798 Scion — Pressure Control Solenoid 'C' Electrical
P0798 Toyota — Pressure Control Solenoid 'C' Electrical
P0798 Volkswagen — Pressure Control Solenoid 'C' Electrical
P0798 Volvo — Pressure Control Solenoid 'C' Electrical

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.