P0948 code meaning
Hydraulic Pump Relay/Control Circuit High
Powertrain system Generic code P09xx codes Check engine light
What P0948 means
The control line of the hydraulic pump relay or driver shows a higher voltage than expected, typically because it is shorted to battery voltage or the relay coil is open on a low-side driver. The pump then cannot be switched on, or the module sees it as active when it is not. J2012 places this code with the pump control circuit; Ferrari however reads P0948 on its DCT as no signal from the system pressure output, an unrelated use. The pump and accumulator unit of an automated gearbox is described in a ZF patent. CARB requires circuit checks on transmission outputs. P0947 is the low counterpart, P0945 the open fault and P0946 the plausibility fault. Expect a warning and possible loss of pump pressure.
P0948 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 P0948
- Warning light on
- Pump does not start
- Gear changes not possible or stop-start disabled
Common causes of P0948
- Most likelyRelay control wire shorted to battery voltage
- PossibleOpen relay coil seen as high level by the driver
- Less likelyControl module fault
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 P0948 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. |
| 48 | The exact fault in that area. |
What to do next
- Note P0948 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 P0948
What does P0948 mean?
P0948 means "Hydraulic Pump Relay/Control Circuit High". The control line of the hydraulic pump relay or driver shows a higher voltage than expected, typically because it is shorted to battery voltage or the relay coil is open on a low-side driver. It is a generic code, so it means the same on every make.
Is it safe to drive with P0948?
Drive gently and only to a workshop. With P0948 the car can go into limp mode (reduced power) to protect itself.
Will P0948 fail an emissions test?
Yes, it can. P0948 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 P0948 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 P0948 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.