P0231 on Mazda
Fuel Pump Secondary Circuit - Low
P0231 on Mazda vehicles indicates fuel pump secondary circuit - low. Au7o has documented this code across 2 Mazda models — most commonly on CX-5, CX-90. 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.
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 Mazda by Model
Mazda CX-5(1 issue)
- Defective Fuel Pump (Denso Recall)2019-2021
Low-pressure fuel pump impellers can deform, causing pump failure and engine stalling without warning. Part of massive global recall affecting 19+ million vehicles across multiple manufacturers.
Mazda CX-90(1 issue)
- Engine Stalling / Loss of Power (Recall Related)2024-2025
The CX-90 has been subject to multiple recalls for engine stalling. Issues include fuel pump control module software errors, turbocharger boost control faults, and engine control module (ECM) programming that can cause unexpected engine shutdown. NHTSA campaigns 24V-014 and 24V-228 address these issues. Engine stalling while driving presents a serious safety risk.
Looking for P0231 on a different make?
View P0231 across all makes →Frequently Asked Questions
What does P0231 mean on Mazda?▼
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 Mazda specifically, this code is documented across 2 models.
What causes P0231 on Mazda vehicles?▼
Common causes on Mazda: 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 Mazda?▼
Repair costs vary widely depending on the root cause and specific Mazda model.
Which Mazda models have P0231 documented?▼
Au7o has documented P0231 on 2 Mazda models: CX-5, CX-90.