P0231 on Mazda: How to Diagnose & Fix
Fuel Pump Secondary Circuit - Low
2 Mazda models · 2 documented issues · 2 critical
P0231 on Mazda by model: symptoms, diagnosis and fix
Low-pressure fuel pump impellers can deform, causing pump failure and engine stalling without warning. Part of a Denso low-pressure fuel pump defect that led to recalls by multiple manufacturers.
Common Symptoms
- Engine no-start condition
- Vehicle stalling at low speeds
- Sudden engine stall at highway speeds (rare but dangerous)
- Loss of power while driving
How to Fix
Dealer replaces fuel pump free of charge under recall. Contact Mazda dealer with VIN to check recall status.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Owner tips & cautions
- TipCheck recall status immediately at Mazda dealer
- TipSchedule repair ASAP - safety risk
- TipKeep fuel tank above 1/2 to reduce pump stress until fixed
- TipDocument any stalling incidents for dealer
Sources for this issue (2)
The CX-90 has been subject to multiple recalls for engine stalling and loss of drive power. Under Recall 7024J (NHTSA 24V815), improper software in the powertrain control module (PCM) and engine control modules (ECM) can illuminate malfunction indicator lights and activate a fail-safe mode that limits drive power; related campaigns cover engine no-restart after i-stop (24V816), PHEV loss of power in EV mode (24V817) and fuel-gauge-related running out of fuel and stalling (25V568). Engine stalling while driving presents a serious safety risk.
Common Symptoms
- Engine stalls unexpectedly while driving
- Loss of power followed by engine shutdown
- Check engine light and multiple warning indicators
- Engine fails to restart immediately after stalling
- Reduced power mode / limp mode activation
How to Fix
Take vehicle to Mazda dealer for recall service. Recall 24V815 involves PCM and ECM reprogramming with improved software (resolving DTC P061B); no fuel pump or turbocharger hardware is replaced. Service is free under recall. Check NHTSA recall lookup with VIN to verify applicability.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Owner tips & cautions
- TipCheck NHTSA.gov recall lookup with your VIN - multiple recalls may apply
- TipSchedule dealer appointment promptly - engine stalling is a safety issue
- TipAll recall repairs are free of charge at any Mazda dealer
- TipIf stalling occurs before recall service, pull to safe location and call roadside assistance (800-222-5500)
Sources for this issue (3)
P0231 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 P0231 mean on a 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 it is documented across 2 models: CX-5, CX-90.
What are the most common causes of P0231?
The most common causes of P0231 are: 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). The specific cause varies by vehicle.
How much does it cost to fix P0231 on a Mazda?
Repair costs vary widely with the root cause and Mazda model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.