P0799 OBD-II Trouble Code: Pressure Control Solenoid “C” Intermittent

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0799 code

P0799 is a diagnostic trouble code (DTC) for "Pressure Control Solenoid “C” Intermittent". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P0799 DIAGNOSTIC Get a fair and transparent estimate upfront

P0799 code definition

The P0799 trouble code detects an issue with one of the pressure control solenoids

What the P0799 code means

The P0799 code is a generic OBD-II trouble code that signals an error with an electronic pressure control solenoid, or possibly the entire solenoid circuit. While the P0799 code can signal an issue with the circuit or multiple solenoids, it specifically detects an error with the “C” solenoid. In vehicles with automatic transmissions, the Powertrain Control Module (PCM) uses data from the engine speed, vehicle speed, throttle position, and engine load to determine the proper hydraulic pressure in the transmission, which helps the transmission shift gears, and aids torque converter lockup. The PCM sends this data to the pressure control solenoids, which then regulate the hydraulic pressure. When the PCM detects that the determined ideal pressure level and the actual pressure level are not the same, then the P0799 code will be triggered.

What causes the P0799 code?

There are a few different things that can cause the P0799 trouble code:

  • Defective pressure control solenoid
  • Insufficient transmission fluid levels
  • Dirty transmission fluid
  • Damaged or faulty electrical components in the system, such as wires and connectors
  • Hydraulic blockages within the fluid passages in the internal transmission
  • Defective high pressure pump
  • Mechanical failures in the internal transmission
  • In rare cases, a defective PCM or transmission control module

What are the symptoms of the P0799 code?

The P0799 trouble code will often be accompanied by the Check Engine Light, which will illuminate on the instrument panel. The car will likely also have transmission problems, which can range from slippage and heating, to harsh shifting or even an inability to shift. It is possible that the torque converter clutch will also refuse to engage or disengage. The car will also likely experience diminished fuel efficiency.

How does a mechanic diagnose the P0799 code?

The P0799 code should be diagnosed with the help of a standard OBD-II trouble code scanner. A certified technician can use the scanner to view the freeze frame data and gather information about the code. The mechanic will also check to see if any additional trouble codes are present. If they are, the codes should be addressed in the order in which they appear on the scanner. The mechanic will then reset the trouble codes and restart the vehicle, to see if the code returns. If the code does not return after this reset, then it should be assumed that the code notes an intermittent issue, or that it was erroneously detected.

If the P0799 code does return, then the mechanic will begin by inspecting the transmission fluid. If the fluid is low it will be refilled, and if it’s dirty it will be replaced. However, if the fluid is heavily contaminated, then there are likely severe issues with the transmission, which may need to be rebuilt or replaced.

The technician will then perform a visual inspection of the electrical components. All damaged wires, connectors, and circuits will need to be replaced.

After this inspection, a manual pressure gauge can be used to check the hydraulic pressure in the system. This information should be compared to the manufacturer’s specifications to see if the pressure is accurate. If the pressure is low, it is likely an issue of blockage, or a malfunctioning pump, solenoid, or regulator. These components can then be inspected and replaced as needed.

If the issue is still not identified, the mechanic will have to perform a more thorough inspection of the entire internal transmission.

After any component is repaired or replaced, the mechanic will need to once again reset the trouble codes and restart the vehicle to see if the code returns. This helps the mechanic know as soon as the issue has been resolved.

Common mistakes when diagnosing the P0799 code

The most frequently made mistakes when diagnosing the P0799 trouble code come from a failure to properly follow the OBD-II diagnostic protocol. When addressing the P0799 code, the protocol should be followed step by step to guarantee an efficient and trustworthy inspection and repair.

It is fairly common for pumps to be replaced, when a simpler problem (such as damaged electrical components) was the only issue.

How serious in the P0799 code?

The drivability of a vehicle with the P0799 code can vary greatly. It is possible that the car is very drivable, with just a few performance issues. It is also possible that the car is virtually inoperable due to a failure to shift and a torque converter clutch that is not responding. For these reasons, and because continuing to drive the vehicle can cause severe damage to the transmission, the P0799 code should always be assessed and repaired as soon as possible.

What repairs can fix the P0799 code?

Repairs for the P0799 trouble code include:

Additional comments for consideration regarding the P0799 code

It is very common for the P0799 code to be accompanied by other codes that deal with similar issues, such as transmission slippage, torque converter clutch, gear ratio, and shift solenoid trouble codes.

This code only applies to vehicles that have automatic transmissions.

Need help with a P0799 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

P0799
trouble codes
Check Engine Light

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P0799 code.

SCHEDULE P0799 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

5,170

Rating Summary
4,765
197
50
27
131
4,765
197
50
27
131

Fred

16 years of experience
364 reviews
Fred
16 years of experience
Mercedes-Benz E500 - Check Engine Light is on - Conroe, Texas
Fred was very friendly and thorough to get to the root of the issue. Even when he could not find a fault to why my engine light was on, he went above and beyond to make absolutely sure that the concern was minimized. Turns out, all that needed to be done was a reset but his diagnostic to address my issues was very intricate and appreciated.

David

17 years of experience
37 reviews
David
17 years of experience
Chevrolet Cruze - Check Engine Light is on - Aurora, Colorado
David was on time, professionalisms & honest! I would definitely request him again and pass along to friends/family.

John

18 years of experience
18 reviews
John
18 years of experience
Dodge Ram 1500 - Check Engine Light is on - Memphis, Tennessee
Demonstrated good integrity. Advised me when work I thought needed done was unnecessary and was helpful in identifying issues that needed to be addressed

Robert

21 years of experience
17 reviews
Robert
21 years of experience
Chrysler 200 - Check Engine Light is on - Fort Worth, Texas
Robert did a good job working on my car and letting me know what's needed to keep my car driving smoothly.


More related articles

P008C OBD-II Trouble Code: Fuel Cooler Pump Control Circuit/Open
P008C means there is an open circuit problem with the fuel cooler system, likely due to a faulty pump or wiring.
P0071 OBD-II Trouble Code: Ambient Air Temperature Sensor Range/Performance
P0071 P0071 code definition Ambient Air Temperature Sensor Range/Performance Issue Depending on the type of vehicle these are some related OBD-II Diagnostic Trouble Codes: P0070: Ambient Air Temperature Sensor Circuit P0072: Ambient Air Temperature Sensor Circuit Low Input P0073:...
B1326 OBD-II Trouble Code: Door Ajar Lamp Circuit Short to Ground
B1326 means there is a circuit error with the door ajar lamp, likely due to a defective door ajar switch, defective door switch, or short circuit.

Related questions

Check engine light in code P0418

The air pump fuse is a 30 amp fuse that powers the pump. The "trigger" for the relay comes from the ignition switch, through a 10 amp fuse. Have you checked to see if the "trigger" wire to the relay...

Stability Light came and Check Engine Light came on. I have a misfire on number 6 plugs.

Your car is equipped with wheel speed sensors at each of the four wheels which monitor wheel speed while relaying this information constantly to the ABS and traction control system which are controlled by the car's ECU. When the ECU...

2008 Kia Rond. Warning light for emissions system came on. Safe to drive? What do I do? Just passed inspection in January.

HI...If the check engine light, or an emissions warning light, is on, one or more diagnostic trouble codes have been set. The first thing to do, though, is make sure that your gas cap is on securely and that there...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com