P0947 code meaning
Hydraulic Pump Relay/Control Circuit Low
Powertrain system Generic code P09xx codes Check engine light
What P0947 means
The voltage on the control line of the hydraulic pump relay or driver is lower than the module expects for the commanded state. Usually the line is shorted to ground or the relay coil is shorted, so the output may be overloaded and the pump runs when it should not, or the driver shuts down. No manufacturer documents this exact code publicly. The hydraulic unit it belongs to, a motor-driven pump that charges an accumulator for the shift and clutch cylinders of an automated gearbox, is described in a ZF patent. CARB requires circuit checks on transmission outputs. P0948 is the high counterpart, P0945 the open fault, P0946 plausibility. Pressure supply for shifting may fail.
P0947 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0947
- Warning light on
- Pump runs continuously or not at all
- Gearbox in limp mode or stop-start disabled
Common causes of P0947
- Most likelyRelay control wire chafed and shorted to ground
- PossibleShorted relay coil
- Less likelyDamaged 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
Hydraulic pump relayWiring harnessTCM
What each part of P0947 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. |
| 47 | The exact fault in that area. |
What to do next
- Note P0947 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 P0947
What does P0947 mean?
P0947 means "Hydraulic Pump Relay/Control Circuit Low". The voltage on the control line of the hydraulic pump relay or driver is lower than the module expects for the commanded state. It is a generic code, so it means the same on every make.
Is it safe to drive with P0947?
Drive gently and only to a workshop. With P0947 the car can go into limp mode (reduced power) to protect itself.
Will P0947 fail an emissions test?
Yes, it can. P0947 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 P0947 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0947 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.