In order to execute a gear change, a specific amount of hydraulic pressure is needed to move each clutch/band and gear into place. This is accomplished by telling the pressure control solenoid to open or close in order to modulate the pressure. If there is an unusually high-voltage signal coming from the pressure control solenoid A control circuit, the ECU will save a P0963 DTC.
How Serious is the Code?
Having a P0963 diagnostic trouble code means that the vehicle’s computer will not be able to manage the hydraulic pressure inside the transmission. This will result in drivability problems that can include hard shifting, slipping between gears and engine stalling.
Symptoms of a P0963 include:
- Transmission slips
- Hard shifting
- Transmission overheating
- Engine stalls when coming to a stop
- Engine misfire-like symptoms
- Limp mode
- Dirty transmission filter and fluid
- Damaged/frayed wiring
- Corroded or broken connectors
- Pressure control solenoid failure
- Transmission pump failure
- Valve body failure
- TCM/ECU problems
How to Diagnose the Code?
In order to properly diagnose a P0963 OBDII trouble code, your mechanic should first start by checking the transmission fluid to see if it is dirty or too low. Next, the wiring and connectors along the transmission wiring harness will have to be checked for signs of damage and corrosion. If no problems have been found up to this point, then the pressure control solenoids will have to be checked, along with possibly the transmission pump, valve body and ECU/TCM.
What Repairs Will Fix P0963?
- Change the transmission fluid and filter
- Repair or replace damaged wiring and connectors
- Install new pressure control solenoid(s)
- Repair or replace transmission pump
- Repair or replace the valve body
- Reprogram or replace the ECU or TCM
- P0960 – Pressure Control Solenoid “A” Control Circuit/Open
- P0961 – Pressure Control Solenoid “A” Control Circuit Range/Performance
- P0962 – Pressure Control Solenoid “A” Control Circuit Low