Skip the auto shop - Our mechanics make house calls

P0963 OBD-II Trouble Code: Pressure Control Solenoid A Control Circuit High

Check Engine Light

P0963 code definition

The P0963 trouble code notes an issue with the pressure control solenoid A control circuit.

What the P0963 code means

The P0963 code is a standard OBD-II trouble code that detects an error with the valve A pressure control solenoid control circuit. The purpose of this solenoid is to regulate the automatic transmission’s hydraulic pressure, which actuates shifting and torque converter lockup. This is controlled by the powertrain control module (PCM), which selects the hydraulic pressure based on the throttle position, engine speed, engine load, and vehicle speed. When the PCM notes that the voltage readings from the pressure control solenoid control circuit in valve A are higher than they should be, the P0963 code is triggered.

What causes the P0963 code?

A few different things can cause the P0963 code to be stored:

  • Malfunctioning valve A pressure control solenoid
  • Defective electrical components, such as wires and connectors
  • Insufficient transmission fluid levels
  • Dirty or contaminated transmission fluid
  • Blockages in the internal transmission’s hydraulic system
  • In rare cases, mechanical issues with the internal transmission
  • In very rare cases, a defective PCM or transmission control module

What are the symptoms of the P0963 code?

The P0963 code is usually accompanied by the Check Engine Light, which will illuminate on the instrument panel. It’s likely that the car will also experience notable transmission problems, such as difficulty shifting, very rough shifting (specifically downshifting), slippage, overheating, and constant stalling at idle. Diminished fuel efficiency is also a common symptom of the P0963 code.

How does a mechanic diagnose the P0963 code?

The P0963 code will be diagnosed using a standard OBD-II trouble code scanner. A reputable mechanic will use the scanner to view the freeze frame data and assess the code, while also looking for additional trouble codes. In the event that multiple codes have been detected, they should be addressed in the order in which they appear. After looking at the freeze frame data the mechanic will clear the trouble codes, restart the vehicle, and check to see if the code returns. If the code is absent, then it is most likely an intermittent issue, or an erroneously detected code.

If the trouble code does remain detected, the mechanic should check the transmission fluid. If the fluid is dirty, or the fluid levels are low, the mechanic will quickly address that. However, if the fluid is severely contaminated, then there is likely a serious issue with the transmission, and it will probably require a rebuild or replacement after inspection.

The technician will then visually inspect the electrical components in the pressure control system, and replace any damaged wires, connectors, or circuits. After doing this, a manual pressure gauge can be connected to the hydraulic pump, which will allow the mechanic to compare the hydraulic pressure to that of the manufacturer’s specifications. If the pressure is too low, then there is likely a defective solenoid, pump, or pressure regulator, or there is a hydraulic fluid blockage.

In the event that the issue has still not been found, then a deeper inspection of the transmission, PCM, and transmission control module will need to be performed.

After any replacements of components, the mechanic will have to halt their inspection and reset the trouble codes, restart the vehicle, and once more check to see if the trouble codes are still present. This will help the mechanic determine as soon as the issue is resolved.

Common mistakes when diagnosing the P0963 code

The most common error when diagnosing the P0963 code comes from failing to comply with the OBD-II trouble code diagnosis protocol. All mechanics should abide by the protocol at all times, to make sure that inspections and repairs are efficient and effective.

High pressure pumps and entire transmissions are often erroneously replaced when simpler components that should have been checked first are the only issue.

How serious is the P0963 code?

Most vehicles with a detected P0963 trouble code will still be operable. In some cases, stalling will be so constant that the vehicle cannot be driven. It is also possible that the transmission will be problematic enough to make driving impractical. Even if the car is perfectly drivable, continuing to operate it with a detected P0963 code can cause severe damage to the transmission, so the code should always be addressed as soon as it is detected.

What repairs can fix the P0963 code?

Potential repairs for the P0963 trouble code are:

Additional comments for consideration regarding the P0963 code

The P0963 trouble code is only found in vehicles that have automatic transmissions.

Need help with a P0963 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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222 code means The manufacturer specifies a range of acceptable voltage to be produced from the throttle position...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...

Related questions

Q: Engine fault reduced power

It sounds like you could have a sticking boost pressure actuator. Unfortunately, YourMechanic does not work on your model vehicle. I suggest having the dealership take a look at it.

Q: check engine light is on -- ge -ot a diagnotics test from onstar -- test stated emmissions system issue whatdoes this mean

Hello, thanks for writing in about your Chevrolet Malibu. If they did not give you the trouble code that is stored then you are going to need to have the system tested to see if the code can be diagnosed...

Q: While highway driving, car stopped accelerating & became inoperative

This message indicates there is a problem in the anti-lock braking and/or electronic stability program system. If the problem is severe enough, the vehicle will go into limp mode, as you experienced. The root cause could be anything from a...