Diagnostic trouble code P0731 — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does P0731 mean?
P0731 indicates: Gear 1 Incorrect Ratio.
This relates to the Transmission system.
Common causes of P0731
Deviation from nominal gear actuator positions detected by continuous monitoring
Heavy wear of a shift fork in the transmission mechanism
Basic setting/gear actuator basic setting procedure not performed after transmission work
Incorrect adaptation values for the gear actuator positions
Wear of selector mechanism parts during break-in or normal use
What to check (live data)
Measured value 12/3 – current gear actuator position (actual value)
Measured value 12/4 – current gear actuator position (actual value)
Adapted longitudinal position for reverse
Adapted rotational position for reverse
Longitudinal position of selector shaft (actual value)
Rotational position of selector shaft (actual value)
Adapted longitudinal positions for individual gears (should not differ significantly between even and odd gears)
Rotary positions and positions of individual gears (should lie within defined values)
Parts often involved in P0731
Shift fork
Gear Recognition Sensor G604
Gear Recognition Sensor G616
Selector shaft
Electro-hydraulic control unit (electromagnetic valves)
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 P0731 — 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.
P0731 is a diagnostic trouble code: Gear 1 Incorrect Ratio.
What are the common causes of P0731?
Common causes include: Deviation from nominal gear actuator positions detected by continuous monitoring, Heavy wear of a shift fork in the transmission mechanism, Basic setting/gear actuator basic setting procedure not performed after transmission work, Incorrect adaptation values for the gear actuator positions. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving with P0731?
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 P0731?
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 P0731 on your specific vehicle.