P0963 code meaning
Pressure Control Solenoid A Control Circuit High
Powertrain system Generic code P09xx codes Check engine light
What P0963 means
Pressure control solenoid A circuit high: the driver detects a short to voltage, and on GM's six-speeds also an open circuit, since those units have no separate open code. The Saab 9-4X 6T70 (line pressure solenoid) sets it after 5 s as Type B, GM's 2018 table after 4.4 of 5 s over two trips; the module then commands maximum line pressure and freezes adaptations. Ford tests its line pressure (EPC) solenoid for short to power and, in some applications, keeps P0963 like P0960 without MIL because maximum line pressure does not raise emissions. GM's 8-, 9- and 10-speeds and Allison 1000 (power short within 75 ms) use A for a clutch or main modulation solenoid. Expect firm, harsh shifts rather than slipping. Siblings: P0960, P0961, P0962.
P0963 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0963
- Firm or harsh shifts at maximum line pressure
- Warning light, on some vehicles only after two drives or not at all
- Shift adaptation no longer improves
Common causes of P0963
- Most likelyOpen coil or high-resistance connection (reported as high on GM six-speeds)
- PossibleControl wire shorted to a supply voltage
- PossibleDamaged or contaminated connector at the transmission
- Less likelyFaulty output stage in the control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid aWiring harnessTCM
What each part of P0963 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9 | Area: transmission. |
| 63 | The exact fault in that area. |
What to do next
- Note P0963 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0963
What does P0963 mean?
P0963 means "Pressure Control Solenoid A Control Circuit High". Pressure control solenoid A circuit high: the driver detects a short to voltage, and on GM's six-speeds also an open circuit, since those units have no separate open code. It is a generic code, so it means the same on every make.
Is it safe to drive with P0963?
Drive gently and only to a workshop. With P0963 the car can go into limp mode (reduced power) to protect itself.
Will P0963 fail an emissions test?
Yes, it can. P0963 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0963 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0963 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.