Fuel Pump B Control Circuit Open
The P2632 code means the vehicle's onboard diagnostic system has detected: Fuel Pump B Control Circuit Open. This is a critical severity code.
- Keep driving?
- No — stop driving
- DIY difficulty
- hard
- Estimated cost
- $300 - $900 (parts and labor)
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Common Symptoms
- Engine no-start or stalling
- Loss of fuel pressure
- Fuel pump B not running
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Failed secondary fuel pump motor Very High
- Open wiring to fuel pump B High
- Blown fuel pump B fuse or relay Moderate
- ECM pump B driver failure Low
Frequently Asked Questions
Why does my vehicle have two fuel pumps?
Many high-performance and direct injection vehicles use a low-pressure supply pump (pump B) to feed a high-pressure injection pump. Both must work for proper operation.
Can I drive if only pump B fails?
No. Pump B typically supplies fuel to the high-pressure pump. Without it, the high-pressure pump runs dry, causing no-start and potential pump damage.
Where is fuel pump B located?
Pump B is usually the in-tank low-pressure supply pump. It is accessed through a panel under the rear seat or by dropping the fuel tank.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Check fuel pump B fuse and relay
-
Test pump B motor with direct power
-
Inspect wiring between ECM and pump B
-
Verify ECM commands pump B operation
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2010-2020 Ford F-150 EcoBoost
- 2012-2020 BMW X5
- 2011-2019 Mercedes-Benz ML350
- 2010-2018 Audi Q7
Related Codes
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