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 a part in your car that helps control the pressure in the transmission is not working all the time. It's like a light switch that sometimes works and sometimes doesn't.
The transmission control system has detected an irregular operation of the pressure control solenoid C, which is responsible for regulating hydraulic pressure for smooth gear shifts.
The P0799 code indicates that the transmission control module (TCM) has detected an intermittent fault in the pressure control solenoid C circuit. This solenoid is crucial for adjusting the hydraulic pressure in the transmission, ensuring proper gear engagement and smooth operation. An intermittent fault suggests that the solenoid or its circuit is not consistently providing the expected performance, which can lead to erratic transmission behavior.
• Erratic or harsh shifting
• Transmission slipping
• Illuminated check engine light
• Faulty pressure control solenoid C
• Wiring issues or poor connections in the solenoid circuit
• Transmission fluid contamination or low fluid level
Transmission Control Module (TCM): A computer that controls the transmission functions.
Solenoid: An electromechanical device used to control fluid flow in the transmission.
• Check the transmission fluid level and condition.
• Inspect wiring and connectors for damage or corrosion.
• Test the pressure control solenoid C for proper operation.
• Replace the faulty pressure control solenoid C.
• Repair or replace damaged wiring or connectors.
• Flush and refill the transmission fluid if contaminated.
• OBD-II scanner
• Multimeter
• Transmission fluid level gauge
$150 - $400
Moderate
• Honda Accord
• Toyota Camry
• Ford F-150
• Regularly check and maintain transmission fluid levels.
• Perform scheduled transmission services.
• Inspect and clean connectors and wiring periodically.
Transmission Control System
• Do not ignore the check engine light; get the car checked as soon as possible.
• Avoid driving at high speeds or towing heavy loads until the issue is resolved.
Check with your vehicle manufacturer; transmission components may be covered under powertrain warranty.
This code has been associated with transmission issues in vehicles with higher mileage or those that have not had regular transmission maintenance.
Moderate – While the vehicle may still be drivable, ignoring this issue can lead to more severe transmission damage.
Driving with a malfunctioning transmission can be dangerous and may lead to further vehicle damage.
• Vehicle must be in a safe, controlled environment.
• Ensure the transmission fluid is at operating temperature.
The pressure control solenoid C is located inside the transmission, typically mounted on the valve body.
Q: Can I drive with a P0799 code?
A: It's not recommended to drive for long periods with this code, as it can cause further transmission damage.
Q: How do I know if the solenoid needs replacement?
A: If the solenoid fails a continuity or resistance test, it likely needs replacement.
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