Powertrain, generic (extended)

P2633 Fuel Pump B Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

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.

Likely causes

Chafed pump wire grounded against frame or tank strap
Shorted pump motor windings
Water in the connector under the vehicle

Symptoms

  • Blown fuse, second pump does not run
  • Fuel not transferred from the auxiliary tank
  • Warning lamp depending on manufacturer

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel pump bwiring harness

Related codes

P2632P2634P2636P0628

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov.