Error code
OBD2 P0731
OBD2P0731
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
Gear 1 Incorrect Ratio.
Severity
moderateCan drive but may experience shifting issues and reduced performance.
Summary
P0731 indicates that the first gear of your transmission has an incorrect ratio, which affects how smoothly and efficiently your vehicle shifts gears.
Symptoms
- Lack of power
- Slow speeds
- Transmission slipping
- Erratic shifting
Common Causes
- Low transmission fluid level
- Dirty transmission fluid
- Transmission oil leak
- Transmission clutch problems
- Low oil pressure
- Faulty transmission control module or speed sensor
- Corroded connections or wiring issues
Diagnosis
- Check transmission fluid level and condition
- Inspect transmission housing for damage
- Test oil pressure in the transmission
- Check speed sensors for proper resistance values
- Inspect wiring circuits for continuity, shorts, or opens
Fixes
- Replace faulty parts such as sensors, solenoids, or seals
FAQ
What should I do if the P0731 code persists after checking fluid levels?
Proceed to inspect and test electrical components like speed sensors and wiring circuits.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
More OBD2 codes
- P0700Transmission Control System (MIL Request)
- P0701Transmission Control System Range/Performance
- P0702Transmission Control System Electrical
- P0703Brake Switch 'B' Circuit
- P0704Clutch Switch Input Circuit Malfunction
- P0705Transmission Range Sensor Circuit Malfunction (PRNDL Input)
- P0706Transmission Range Sensor Circuit Range/Performance
- P0707Transmission Range Sensor Circuit Low
- P0708Transmission Range Sensor Circuit High
- P0709Transmission Range Sensor Circuit Intermittent
- P0710Transmission Fluid Temperature Sensor 'A' Circuit
- P0711Transmission Fluid Temperature Sensor 'A' Circuit Range/Performance