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:
- Replacement of the valve A pressure control solenoid
- Replacement of the wires and connectors in the system
- Replacement of high pressure pumps
- Replacement or addition of transmission fluid
- Removal of hydraulic blockages from the transmission
- In rare cases, replacement of the transmission
- In very rare cases, replacement of the PCM or transmission control module
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.