Subaru will be contacting the owners of certain Legacy and Outback vehicles regarding a problem affecting the drive train in their vehicles.
Certain 2020-2021 Subaru Legacy and 2020-2021 Subaru Outback vehicles could experience a programming error in the Transmission Control Unit (TCU) that could result in an improperly secured drive chain. This recall is an extension of safety recall 21V-99 filed, in December 2021. Subaru has determined that another 182 pre-production vehicles have not been repaired, and need to be added to the list.
According to the defect report filed with the National Highway Traffic Safety Administration (NHTSA), an improperly programmed TCU could result in insufficient clamping pressure on the vehicle drive chain. If the shift select was moved to drive or reverse (D or R) immediately after the engine was started, the independent secondary pressure control program may allow the F/R clutch to begin engagement before enough secondary clamping pressure has been applied. An insufficient clamping pressure could result in the drive chain slipping and becoming damaged. Due to the increased force, the chain guide could break apart and the fragments could inhibit the shift select mechanism. If the vehicle continues to operate with the drive chain slipping, the drive chain could eventually break. If this happens while a vehicle is in motion, the vehicle will experience a loss of motive power, increasing the risk of a crash.
Owners receiving notices will be asked to return to their Subaru dealer to have the TCU reprogrammed. The historical TCU data will be analyzed for chain slip characteristics and the chain guide will be visually inspected for damage. If vehicles are confirmed to be experiencing drive chain slip or if the chain guide is damaged, the transmission assembly will be replaced. Subaru's number for this recall is WRK-22 and the NHTSA campaign number is 22V-485.