Code result
P0731
Gear 1 Incorrect Ratio
High severity
What it means
When gear 1 is engaged, the measured ratio between the input- and output-shaft speed sensors does not match the expected ratio for that gear. This means the transmission is slipping in gear 1 rather than transmitting power solidly. Causes: worn clutch packs or bands, low fluid level or pressure, a stuck shift solenoid, or a valve-body fault affecting gear 1.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
1st gear clutch pack worn
highOne of the most commonly reported causes for this code — check this first.
Line pressure low (pump or valve body)
mediumA plausible cause — test and verify before replacing parts.
Related help
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