Powertrain, generic (extended)

P2632 Fuel Pump B Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Fuel pump B is a second pump beside the main one: a transfer pump between two tanks, an in-line booster or a second in-tank pump. P2632 reports an open in its control circuit. On the 6.6 L LML Duramax with dual tanks, GM's 2014 table 14OBDG10 drives the transfer pump relay through a low-side driver and sets the code as Type B after 3 s above 200 kOhm. In the 2020 diesel table 20OBDG04 it is a Type C code without MIL after 20 of 25 samples. Bulletin PIT5212B on 2013 Silverado/Sierra 3500 chassis cabs asks for a scan tool update before diagnosis. VW sets it below 0.8 mA for the in-line pump of 2014 Golf and Beetle; Ford's 2020-2023 summary uses P2632 for driver feedback faults of pump module B.

Likely causes

Failed transfer pump relay, fuse or relay socket
Open wire or corroded connector at the pump or tank
Pump motor or pump driver module open internally
Outdated scan tool cannot command the pump (GM PIT5212B)

Symptoms

  • Fuel from the second tank is not transferred, gauge drops faster
  • Possible stalling when the main tank runs dry
  • 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 bfuel pump relay bwiring harness

Related codes

P2633P2634P2636P0230P0627

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