P2634 code meaning
Fuel Pump B Control Circuit High
Powertrain system Generic code P26xx codes Check engine light
What P2634 means
P2634 indicates that the drive of the second fuel pump reads as shorted to battery voltage or carries too much current. For the 6.6 L LML with dual tanks, GM's 2014 table judges the transfer pump relay output while it is switched on and treats 0.5 ohm or less toward controller power, lasting 3 s, as a Type B fault. GM's 2020 diesel table checks the transfer pump driver while it is off instead and logs a Type C code after 20 of 25 samples; it notes that the open-circuit code P2632 may appear alongside. VW uses an overcurrent limit of 1.0 A for the in-line pump on 2014 Golf/GTI and Beetle. A pump with worn brushes or a shorted relay coil can cause it as well as damaged wiring. The open and low faults are P2632 and P2633.
P2634 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2634
- Second pump runs constantly or is shut off by the module
- Fuel level display between tanks inconsistent
- Warning lamp depending on manufacturer
Common causes of P2634
- Most likelyControl wire shorted to a battery-voltage feed
- PossibleWorn or binding pump drawing excess current
- Less likelyRelay with shorted coil or stuck contacts
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pump bWiring harness
What each part of P2634 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 6 | Area: computer (engine control module) and output circuits. |
| 34 | The exact fault in that area. |
What to do next
- Note P2634 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 P2634
What does P2634 mean?
P2634 means "Fuel Pump B Control Circuit High". P2634 indicates that the drive of the second fuel pump reads as shorted to battery voltage or carries too much current. It is a generic code, so it means the same on every make.
Is it safe to drive with P2634?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2634 fail an emissions test?
Yes, it can. P2634 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 P2634 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P2634 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.