Wrench light on 2010 Forester 3171DS. Stays in 3rd gear.

[NoviceEureka]

On startup, starts out in 1st gear, shifts to 2nd, then 3rd. Wrench light comes on (along with check engine light). As long as engine stays running transmission stays in 3rd. Starts in 3rd from stop thereafter. Manual downshifts are ignored. Goes into reverse OK from stop, but goes back into 3rd in Drive. Turn ignition off, restart, wrench light clears, and trans starts in 1st again. But once in 3rd, that's where it stays until engine off.


Disconnected negative cable from battery and shorted across negative cable and battery positive to drain capacitors as advised. Cleared check engine and wrench lights, but they come back on first 1st-to-3rd sequence.


6.8L V10 with Tow/Haul (transmission code "T" (TorqShift?))


Any advice? Thanks!

[NoviceEureka]

Turns out that the wrench light (limp home mode) was caused by the Turbine Shaft Speed (TSS) Sensor and Intermediate Shaft Speed (ISS) Sensor wires being chewed off right at the connector on our TorqShift 5R110W. OBDII scan tool showed codes P0715, P0720, and P0791. P0720 is the Output Shaft Speed (OSS) Sensor. P0715 and P0791 are for the combined TSS-ISS sensor. My 15-year-old son used his shop class skills to solder everything back together. We cleared the codes, and everything is good now.

[Lins]

Good job fixing it yourself. Any idea why the wires got damaged in the first place?

[NoviceEureka]

All four were chewed off right at the base of the plug. I suspect one of the many squirrels and chipmunks that inhabit the trees on our lot. This sensor is almost on top of the transmission and very close to the floor right where the engine cover joins it. I remember finding some nut hulls in the valley between the banks of cylinders back in June. Going to try the peppermint oil spray to keep them out.

[Lins]

I'm hearing that more and more with newer vehicles unfortunately.