P0232 on GMC: How to Diagnose & Fix
Fuel Pump Secondary Circuit - High
2 GMC models · 2 documented issues · 2 critical · $350-$1,200 repair
P0232 on GMC by model: symptoms, diagnosis and fix
The GMC Savana (and Chevrolet Express) fuel pump module is known for premature failure between 80,000-140,000 miles, often stranding drivers without warning. The in-tank electric fuel pump motor burns out or the sending unit becomes erratic. Running the tank consistently below 1/4 generates heat that shortens pump life. Commercial use Savanas that frequently run low on fuel — common in fleet operations — see pump failures well before 80,000 miles. The fuel pump is a demanding repair requiring tank removal on the Savana.
Common Symptoms
- Hard start or extended cranking before engine fires
- Engine stalls at idle and won't restart when hot
- Fuel pressure below specification (should be 55-60 psi)
- Engine stumbles and hesitates under load
- No-start condition with no fuel pressure
- Fuel gauge erratic or reads wrong
How to Fix
Replace fuel pump module (ACDelco MU1374 for 6.0L Savana, MU1373 for 4.8L). Keep fuel tank above 1/4 full at all times. For fleet vehicles, replace pump proactively at 100,000 miles. Aftermarket Walbro or Delphi pumps are common alternatives.
Sources for this issue (1)
A common GMT800 Sierra problem is failure of the in-tank fuel pump module, often from worn pump motors or failed level-sender/module electronics. Owners report long crank, hard starting, loss of power under load, or sudden stall/no-start conditions, especially as mileage climbs. This issue is widely documented in owner forums and complaint databases across 4.3L, 4.8L, 5.3L, and 6.0L trucks.
Common Symptoms
- long crank before starting
- intermittent no-start
- engine stalls while driving
- loss of power on acceleration
- fuel gauge may act erratically if sender/module is failing
- whining noise from fuel tank
How to Fix
Diagnosis usually starts with checking fuel pressure at the rail and verifying pump prime at key-on. Low or unstable pressure, especially after sitting, points to a weak pump or failing module. Repair is replacement of the complete fuel pump module and, ideally, the fuel filter on applicable years; corroded electrical connectors at the tank should also be inspected and replaced if heat-damaged.
Sources for this issue (1)
P0232 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 P0232 mean on a GMC?
P0232 stands for "Fuel Pump Secondary Circuit - High." This code means the engine computer has detected a high voltage signal in the fuel pump secondary (control) circuit, indicating the circuit that drives or monitors the fuel pump relay is reading higher than it should. The computer controls fuel pump power delivery through a relay and/or driver module, and a high reading suggests a short to voltage, a stuck relay, or a wiring fault in that control circuit. Depending on the fault, it can cause hard starting, stalling, or a no-start because fuel delivery is disrupted. The problem is typically electrical, in the relay, driver, or wiring, rather than the pump motor itself. On GMC it is documented across 2 models: Savana, Sierra 1500.
What are the most common causes of P0232?
The most common causes of P0232 are: Faulty fuel pump relay (stuck or shorted), Short to voltage in the fuel pump control wiring, Failed fuel pump driver module, Corroded or damaged connectors in the circuit, Faulty fuel pump (internal short), Wiring chafed against the body or harness short, Faulty PCM/ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0232 on a GMC?
Published repair estimates on GMC range from $350 to $1,200 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0232 on a different make?
View P0232 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.