P2633Fuel Pump B Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2633 is the ground-short code of the second fuel pump circuit. GM's 2014 LML diesel table checks the ground-switched relay output of the fuel transfer pump while it is off and flags 0.5 ohm or less between signal and ground, held for 3 s, as Type B. The 2020 diesel table 20OBDG04 looks at the supply-side switch of the rear-tank transfer pump while it is on and stores a Type C code, without warning lamp, after 20 failures in 25 samples of 250 ms. VW's 2014 data books for Golf, GTI and Beetle set P2633 for the auxiliary in-line pump once the signal voltage stays under 2.0 V. GM bulletin PIT5212B groups it with P2632, P2634 and P2636 on 2013 dual-tank chassis cabs. A grounded wire usually blows a fuse or stops the pump.
- What you may notice
- Blown fuse, second pump does not run
- Fuel not transferred from the auxiliary tank
- Warning lamp depending on manufacturer
- Likely causes
- LikelyChafed pump wire grounded against frame or tank strap
- PossibleShorted pump motor windings
- RareWater in the connector under the vehicle
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.