P2634 on Chevrolet: How to Diagnose & Fix
Fuel Pump "B" Control Circuit High
1 Chevrolet model · 1 documented issue
P2634 on Chevrolet by model: symptoms, diagnosis and fix
GM released Bulletin #25-NA-284, 'Information on DTCs P2632 and/or P2634 Found During a GDS 2 Scan for Another Concern,' with fitment limited to 2025 model year Corvettes equipped with the 5.5L twin-turbo LT7 - the ZR1. The bulletin's framing matters: these codes turn up as stored history codes while a technician is scanning for an unrelated complaint, which is exactly the situation where an aftermarket shop tends to sell an unnecessary repair. This is a diagnostic-information bulletin for the LT7 fuel/pump control DTC block, not a repair authorization.
Common Symptoms
- DTC P2632 and/or P2634 found stored during a GDS2 scan performed for an unrelated concern
- Often no driveability symptom present
How to Fix
If a scan turns up P2632 and/or P2634 on a 2025 ZR1 while chasing an unrelated concern, have the shop read Bulletin #25-NA-284 before quoting any work - GM published it precisely so these codes are not treated as a standalone failure. Clear the codes, address the original complaint, and only pursue these DTCs further if they reset as current codes with an actual driveability symptom.
Sources for this issue (1)
P2634 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P2634 mean on a Chevrolet?
P2634 stands for "Fuel Pump "B" Control Circuit High." The PCM detects a high-voltage condition (short to power or floating high) on the fuel pump 'B' control circuit, so the pump is not controlled correctly. On Chevrolet it is documented across 1 model: Corvette.
What are the most common causes of P2634?
The most common causes of P2634 are: Short to voltage in the fuel pump 'B' circuit, Open circuit floating high, Faulty fuel pump or relay, Wiring/connector damage, PCM driver fault. The specific cause varies by vehicle.
How much does it cost to fix P2634 on a Chevrolet?
Repair costs vary widely with the root cause and Chevrolet model; each issue on this page carries its own estimate where one is published.
Looking for P2634 on a different make?
View P2634 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.