Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that something is wrong with the part of the car that helps control the pressure of the fluid in the transmission. It's like a switch that isn't working right, and it can make the car not drive smoothly.
The P0798 code is triggered when the transmission control module (TCM) detects an electrical problem with the pressure control solenoid C circuit.
The pressure control solenoid C is responsible for regulating hydraulic pressure within the transmission. This solenoid helps control the shifting of gears by adjusting the pressure applied to the transmission clutches and bands. An electrical issue in this solenoid's circuit can lead to improper transmission operation.
• Transmission slipping
• Harsh or erratic shifting
• Transmission overheating
• Check Engine Light illuminated
• Poor fuel economy
• Faulty pressure control solenoid C
• Wiring issues in the solenoid circuit
• Poor electrical connection
• Transmission fluid contamination
• Faulty transmission control module (TCM)
Transmission Control Module (TCM): A computer that controls the operation of the transmission.
Solenoid: An electromechanical device used to control fluid flow in the transmission.
• Use an OBD-II scanner to confirm the code.
• Inspect the transmission fluid level and condition.
• Check the wiring and connectors for damage or corrosion.
• Test the pressure control solenoid C for proper operation.
• Inspect the transmission control module (TCM) for faults.
• Replace the faulty pressure control solenoid C.
• Repair or replace damaged wiring or connectors.
• Flush and replace contaminated transmission fluid.
• Reprogram or replace the transmission control module (TCM) if necessary.
• OBD-II scanner
• Multimeter
• Transmission fluid pressure gauge
$200 - $600
Moderate
• Honda Accord
• Toyota Camry
• Ford F-150
• Regular transmission fluid changes
• Routine transmission inspections
• Address transmission issues promptly
Transmission Control Issue
• Avoid driving the vehicle if the transmission is slipping.
• Have the vehicle inspected by a qualified mechanic as soon as possible.
Check with your vehicle manufacturer for warranty coverage on transmission components.
This code has been associated with issues in vehicles with automatic transmissions, especially those with higher mileage.
Moderate – It should be addressed soon to prevent further transmission damage.
Driving with a faulty transmission can be dangerous. Ensure repairs are made promptly to maintain vehicle safety and compliance with emissions regulations.
• Vehicle at operating temperature
• Transmission in drive
The pressure control solenoid C is located inside the transmission, usually attached to the valve body.
Q: Can I drive with a P0798 code?
A: It's not recommended to drive with this code active, as it can lead to further transmission damage and unsafe driving conditions.
Q: How can I prevent P0798 from occurring?
A: Regular maintenance, including transmission fluid changes and inspections, can help prevent this issue.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.