P0731 on Volvo
Gear 1 Incorrect Ratio
P0731 on Volvo vehicles indicates gear 1 incorrect ratio. Au7o has documented this code across 1 Volvo model — most commonly on S60. This code means the Transmission/Powertrain Control Module detected an incorrect gear ratio in 1st gear. The module compares input (engine/turbine) speed to output shaft speed; when the car is commanded into 1st but the calculated ratio doesn't match the expected value, P0731 sets. This points to slipping, an incorrect shift, or a hydraulic/mechanical problem rather than just an electrical fault. You may feel slipping, harsh or delayed engagement, or the transmission may go into a limited 'limp' mode. Typical repair costs on Volvo range from $900 to $4,500, depending on the specific model and root cause.
Common Causes of P0731
- •Low or degraded/burnt transmission fluid
- •Slipping clutch packs or worn friction components
- •Stuck or faulty shift solenoid affecting 1st gear
- •Internal hydraulic leak / valve body fault
- •Worn or failing torque converter
- •Faulty input or output speed sensor
- •Mechanical wear (planetary gears, bands) inside the transmission
P0731 on Volvo by Model
Volvo S60(1 issue)
- AW55-50SN 5-Speed Automatic Transmission and TCM Failure2001-2009
P2-generation S60s use the Aisin-Warner AW55-50SN 5-speed automatic. Two related failures dominate owner reports: the transmission control module (TCM), which is mounted inside the transmission case and bathed in hot ATF, develops cracked solder joints and internal failures, and the transmission's clutch packs and valve body wear prematurely because Volvo originally specified the fluid as 'lifetime fill'. Symptoms usually begin as harsh or delayed 1-2 and 2-3 shifts, then progress to flare-ups, limp-home mode (locked in 3rd gear), and eventually loss of forward or reverse. Owners on CarComplaints report 'Transmission/TCU Failure' and 'Lost Forward And Reverse' on early cars, and NHTSA has 16+ automatic-transmission complaints on the 2001 alone.
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What does P0731 mean on Volvo?▼
P0731 stands for "Gear 1 Incorrect Ratio." This code means the Transmission/Powertrain Control Module detected an incorrect gear ratio in 1st gear. The module compares input (engine/turbine) speed to output shaft speed; when the car is commanded into 1st but the calculated ratio doesn't match the expected value, P0731 sets. This points to slipping, an incorrect shift, or a hydraulic/mechanical problem rather than just an electrical fault. You may feel slipping, harsh or delayed engagement, or the transmission may go into a limited 'limp' mode. On Volvo specifically, this code is documented across 1 model.
What causes P0731 on Volvo vehicles?▼
Common causes on Volvo: Low or degraded/burnt transmission fluid, Slipping clutch packs or worn friction components, Stuck or faulty shift solenoid affecting 1st gear, Internal hydraulic leak / valve body fault, Worn or failing torque converter. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0731 on a Volvo?▼
Repair costs on Volvo range from $900 to $4,500, depending on the specific model and root cause.
Which Volvo models have P0731 documented?▼
Au7o has documented P0731 on 1 Volvo model: S60.