AutoCodes – Lexus – P0798 Lexus

P0798 Lexus Code - Pressure Control Solenoid 'C' Electrical

Quick Answer

Changing from 1st to 6th is performed by the Engine Control Module (ECM) turning shift solenoid valves SL1, SL2, SL3, SL4, and SL on and off. Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Pressure Control Solenoid 'C' valve (Shift Solenoid Valve SL3). 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 Lexus indicates Pressure Control Solenoid 'C' Electrical.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Pressure Control Solenoid 'C' valve (Shift Solenoid Valve SL3).
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 7,851

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 Sep 12, 2022

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 Lexus Description

Changing from 1st to 6th is performed by the Engine Control Module (ECM) turning shift solenoid valves SL1, SL2, SL3, SL4, and SL on and off. If an open or short circuit occurs in any of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated.
The ECM commands gear shifts by turning the shift solenoid valves on and off. According to the input shaft speed, intermediate (counter) shaft speed, and output shaft speed, the ECM detects the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear). When the gear commanded by the ECM and the actual gear are not the same, the ECM illuminates the MIL and stores the Diagnostic Trouble Code (DTC).

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

What does this mean?

What are the Possible Causes of the DTC P0798 Lexus?

Low transmission fluid level
Dirty transmission fluid
Faulty Pressure Control Solenoid 'C' valve (Shift Solenoid Valve SL3)
Pressure Control Solenoid 'C' valve harness is open or shorted
Pressure Control Solenoid 'C' valve circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0798 Lexus?

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 malfunction, 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, remove 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 Lexus 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 Lexus code?

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

Need Help with the Code?

Get the P0798 Lexus 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 Lexus Code

1. What are the common symptoms of OBDII code P0798 in a Lexus related to the Pressure Control Solenoid 'C' Electrical issue?

- Common symptoms include harsh shifting, transmission slippage, decreased fuel efficiency, and the illumination of the check engine light.

2. What are the possible causes of the OBDII code P0798 in a Lexus indicating an issue with the Pressure Control Solenoid 'C' Electrical?

- Potential causes may include a faulty pressure control solenoid 'C', damaged wiring or connectors, low transmission fluid levels, or a malfunctioning transmission control module.

3. How can I diagnose the OBDII code P0798 in my Lexus related to the Pressure Control Solenoid 'C' Electrical problem?

- Diagnosis typically involves using a scan tool to retrieve the trouble code, inspecting the wiring and connectors for any damage, testing the solenoid for proper operation, and checking the transmission fluid level and condition.

4. Is it safe to continue driving my Lexus with the OBDII code P0798 indicating an issue with the Pressure Control Solenoid 'C' Electrical?

- It is not recommended to drive the vehicle extensively with this code present, as it can lead to further damage to the transmission and potentially leave you stranded. It is best to address the issue promptly.

5. Can I repair the OBDII code P0798 in my Lexus related to the Pressure Control Solenoid 'C' Electrical on my own?

- Repairing this issue may require specialized tools and knowledge of automotive systems. It is advisable to seek assistance from a qualified mechanic or technician to properly diagnose and repair the problem.

6. How much does it typically cost to repair the OBDII code P0798 in a Lexus caused by the Pressure Control Solenoid 'C' Electrical malfunction?

- Repair costs can vary depending on the exact cause of the issue, labor rates, and the cost of replacement parts. It is recommended to obtain estimates from different repair shops for an accurate assessment.

7. Are there any preventive maintenance tips to avoid encountering the OBDII code P0798 related to the Pressure Control Solenoid 'C' Electrical in my Lexus?

- Regular transmission fluid checks and changes, avoiding aggressive driving habits, and addressing any transmission-related issues promptly can help prevent the occurrence of this code.

8. Can a faulty Pressure Control Solenoid 'C' impact the overall performance of my Lexus transmission system?

- Yes, a malfunctioning pressure control solenoid 'C' can lead to erratic shifting, poor fuel economy, and potential long-term damage to the transmission if left unresolved.

9. How urgent is it to address the OBDII code P0798 in a Lexus indicating an issue with the Pressure Control Solenoid 'C' Electrical?

- It is recommended to address this issue promptly to prevent further damage to the transmission system and ensure the safe operation of your vehicle.

10. Will resetting the check engine light make the OBDII code P0798 related to the Pressure Control Solenoid 'C' Electrical disappear permanently?

- Resetting the check engine light may temporarily clear the code, but if the underlying issue causing the code is not addressed, it is likely to reappear. It is essential to diagnose and repair the problem to resolve the code permanently.