P0231

Q: What does OBD2 code P0231 mean?

P0231 means: Fuel Pump Secondary Circuit Low. The fuel pump feedback circuit voltage is lower than expected, indicating the pump is not running at proper voltage.

Fuel Pump Secondary Circuit Low

The fuel pump feedback circuit voltage is lower than expected, indicating the pump is not running at proper voltage.

SeverityCritical

CategoryFuel System

Est. Repair Cost$200–$800

Code TypePowertrain

DIY RepairProfessional

⚡ Common Causes

›High resistance in fuel pump wiring
›Weak fuel pump
›Corroded connectors in pump circuit
›Failed pump driver module

⚠️ Symptoms

›Hard starting
›Engine stalling
›Loss of power at high demand
›Check engine light

✅ How to Fix — Step by Step

Step 1:Test voltage at fuel pump connector under load
Step 2:Inspect pump wiring for high resistance
Step 3:Replace fuel pump if current draw is excessive
Step 4:Replace fuel pump driver module if equipped

🔧 Diagnostic Tools Required

✔OBD-II Diagnostic Scanner
✔Digital Multimeter
✔Basic Hand Tools
✔Flashlight
✔Vehicle Service Manual

Using the correct diagnostic tools helps identify the root cause of P0231 before replacing parts unnecessarily. Always confirm the fault using live data and manufacturer-recommended diagnostic procedures.

💡 Pro Tip: Test voltage AT the fuel pump connector — a voltage drop of more than 0.5V indicates excessive resistance in the wiring.

Repair Cost Estimate

Full Repair Estimate

$200–$800

DIY Possible?

PRO

Severity

Critical

Frequently Asked Questions

What does OBD2 code P0231 mean?+

P0231 stands for Fuel Pump Secondary Circuit Low. The fuel pump feedback circuit voltage is lower than expected, indicating the pump is not running at proper voltage.

What causes code P0231?+

High resistance in fuel pump wiring; Weak fuel pump; Corroded connectors in pump circuit; Failed pump driver module

How do I fix code P0231?+

Test voltage at fuel pump connector under load; Inspect pump wiring for high resistance; Replace fuel pump if current draw is excessive; Replace fuel pump driver module if equipped

How much does it cost to fix P0231?+

Estimated repair cost for P0231 is $200–$800.

Is P0231 DIY-friendly?+

P0231 typically requires professional equipment and a qualified mechanic.