pump operating voltage (maximum electrical system voltage or reduced to 10V depending on fuel demand)
control signal A (blue wire) from engine control module to fuel pump control module
feedback signal B (green wire) from fuel pump control module to engine control module
output voltage values from fuel pump control module monitored for plausibility
Parts often involved in P0231
fuel pump G6 (pre-supply pump)
transfer fuel pump G23
fuel pump relay J17
fuel pump control module J538
Motronic engine control module J220
Don't replace parts until the root cause is confirmed — many of these codes are caused by wiring, a connector or an upstream fault, not the part itself.
Get the confirmed root cause for P0231 — on YOUR vehicle
A code is a symptom, not a diagnosis. AutoDX Pro cross-checks several
independent assessments, pinpoints the actual root cause, gives you the
exact tests to confirm it, and shows the parts — only after the cause is
confirmed. Reads your scan-tool photo and decodes your VIN with open
recalls.
P0231 is a diagnostic trouble code: Fuel Pump Secondary Circuit Low.
What are the common causes of P0231?
Common causes include: fuel pump control module J538 not switching fuel pump relay J17, fault in connection between engine control module J220 and fuel pump control module J538, output voltage from fuel pump control module out of plausibility range, fuel pump relay J17 failure preventing pump actuation. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving with P0231?
It depends on the fault and your symptoms. Some causes are minor, others can damage components or affect safety. Get the root cause confirmed before deciding.
How do I fix P0231?
Confirm the actual root cause with targeted tests first, then replace only the part that's at fault. AutoDX Pro gives you the root cause, the exact tests, and the parts for P0231 on your specific vehicle.