P0231 on GMC
Fuel Pump Secondary Circuit - Low
P0231 on GMC vehicles indicates fuel pump secondary circuit - low. Au7o has documented this code across 7 GMC models — most commonly on C/K 3500, Safari, Savana. This code indicates the engine computer detected a low-voltage condition in the fuel pump's secondary (driver/output) control circuit. Many vehicles control the fuel pump through a relay or a dedicated driver module, and the computer monitors the voltage on that circuit to confirm the pump is being powered correctly. When the feedback voltage stays lower than expected, P0231 sets. Because the fuel pump supplies pressurized fuel to the injectors, this fault can cause hard starting, stalling, or no-start conditions. Typical repair costs on GMC range from $300 to $1,200, depending on the specific model and root cause.
Common Causes of P0231
- •Faulty fuel pump relay
- •Corroded or loose connector at the pump or relay
- •Damaged or shorted wiring in the pump power circuit
- •Poor ground for the fuel pump circuit
- •Failing fuel pump drawing abnormal current
- •Faulty fuel pump driver module
- •PCM/ECM internal driver fault (rare)
P0231 on GMC by Model
GMC C/K 3500(1 issue)
- In-Tank Fuel Pump Premature Failure1990-2000
The C/K 3500 uses an in-tank electric fuel pump that fails prematurely, often at 80,000-120,000 miles. The truck's large fuel tank (up to 42 gallons) means the pump works harder to maintain pressure over a longer fuel column. Running the tank below 1/4 regularly accelerates failure because the fuel cools and lubricates the pump — low fuel means less cooling. The dual-tank models are particularly problematic as the fuel switching valve can fail and starve one pump.
GMC Safari(1 issue)
- In-Tank Fuel Pump Failure1990-2005
Common fuel pump failure. The Safari twin-tank models have additional complexity with the tank switching system.
GMC Savana(1 issue)
- Fuel Pump Module Failure and Hard Start / Stalling2003-2020
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.
GMC Sierra 1500(1 issue)
- Fuel Pump Module Failure Causing No-Start or Stalling2000-2007
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.
GMC Sonoma(1 issue)
- In-Tank Fuel Pump Failure1991-2004
Same fuel pump failure issues as the S-10. The in-tank pump fails from heat and debris.
GMC Suburban(1 issue)
- Fuel Pump Failure in Large Tank1996-1999
The in-tank fuel pump works harder due to the Suburban's large fuel tank (42 gallons) and fails prematurely. The pump draws more current to push fuel the longer distance to the engine, leading to burnout.
GMC Yukon XL(1 issue)
- Fuel Pump Module Failure Leading to No-Start or Intermittent Stalling2000-2006
In-tank fuel pump module failure is a common GMT800 problem, especially as mileage climbs or when vehicles are frequently run near empty. Owners report extended cranking, hard starts after sitting, sudden stalling, loss of power under load, or complete no-start conditions. The issue is well represented in owner reports and repair histories across 5.3L, 6.0L, and 8.1L applications.
Looking for P0231 on a different make?
View P0231 across all makes →Frequently Asked Questions
What does P0231 mean on GMC?▼
P0231 stands for "Fuel Pump Secondary Circuit - Low." This code indicates the engine computer detected a low-voltage condition in the fuel pump's secondary (driver/output) control circuit. Many vehicles control the fuel pump through a relay or a dedicated driver module, and the computer monitors the voltage on that circuit to confirm the pump is being powered correctly. When the feedback voltage stays lower than expected, P0231 sets. Because the fuel pump supplies pressurized fuel to the injectors, this fault can cause hard starting, stalling, or no-start conditions. On GMC specifically, this code is documented across 7 models.
What causes P0231 on GMC vehicles?▼
Common causes on GMC: Faulty fuel pump relay, Corroded or loose connector at the pump or relay, Damaged or shorted wiring in the pump power circuit, Poor ground for the fuel pump circuit, Failing fuel pump drawing abnormal current. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0231 on a GMC?▼
Repair costs on GMC range from $300 to $1,200, depending on the specific model and root cause.
Which GMC models have P0231 documented?▼
Au7o has documented P0231 on 7 GMC models: C/K 3500, Safari, Savana, Sierra 1500, Sonoma, Suburban, Yukon XL.