P2763 code Subaru — How to diagnose and fix

Learn what a  P2763 code means, how to diagnose it and how to fix the problem

P2763 Lock-Up Duty Solenoid Circuit (High) Lock-up duty solenoid is faulty or output signal circuit is open or shorted.

A P2763 code is defined as: Lock-Up Duty Solenoid Circuit (High) Lock-up duty solenoid is faulty or output signal circuit is open or shorted. This code pertains to the lock up feature in the torque converter of the automatic transmission.

How a lock-up torque converter works

A torque converter’s job is to take the place of a mechanical clutch and transfer rotational torque from the engine to the transmission. In its simplest form, a torque converter works like two fans facing each other. One fan is connected to the engine and it blows transmission fluid at the second fan, causing it to rotate. Some of the torque force is lost due to heat. To get better MPG, the carmakers include a lock up feature so the two fans are locked together (again, a very simple explanation; it’s really more complicated than that).
To achieve the lock up, a solenoid pulses transmission fluid pressure into a port on the torque converter, forcing a fan component to press against clutch material, effectively locking the two fans together.

During lock up, high transmission fluid pressure forces the clutch disc against the cover, so the two rotate at exactly the same speed. The clutch hub is splined to the shaft running through the torque converter, so 1:1 torque is transmitted directly into the transmission, avoiding torque loss between the turbine and impeller.

The operation of the torque converter clutch lock-up feature is controlled by the transmission control module and the lock-up solenoid. The TCM monitors voltage to the solenoid so it can detect an open or short condition. In a P2763 code situation, the TCM is seeing high voltage, which usually means there’s an open in the solenoid coil windings. In other words, the solenoid has failed.

How to diagnose a P2763 code

You’ll be testing the lock-up solenoid for an open or short to ground condition.

1) Disconnect the negative battery cable.
2) Start by unplugging the connectors between the TCM and the transmission.
3) Using your multimeter set to the ohms scale, check the resistance on pin 11 (white wire) and the transmission case. You should see around 13Ω. If you don’t see this value, the causes can be a bad lock-up solenoid OR an electrical issue with the internal wiring inside the transmission. However, this is a very common failure point on the Subaru CVT transmissions up to around the 2017 model year.
4) Next, check the current draw of the lock-up solenoid by applying power to the white wire. It should draw less than 1-amp.
5) Lastly, check for continuity on the white wire between the transmission and the TCM to rule out a wiring harness issue.
6) Check the wiring between the transmission connector and the TCM. Pin 11 Red/White on the harness side of the transmission connector goes to pin A26 of the TCM.

Subaru doesn’t sell the lock-up solenoid as a separate piece. So you must replace the entire valve body. It’s located on top of the transmission.