AT Transmission light/TC light/P0470 code

[Dreamliner]

Driving home from the grocery store this afternoon I was waiting to turn right on a red light. I began coasting forward without any throttle and looked down to see my Traction Control light was illuminated. There was no reason for TC system to be active obviously. I tried turning off the TC system with the button to no avail. As I began to accelerate the car wouldn't shift to 2nd even when I put it into manual mode (I got the "M" but no gear indication and then the AT light came on). I pulled off immediately and tried shutting off the engine and re-starting it. All went fine but the check engine light stayed on. No issues shifting on the way home. The code I got is a P0470 which indicates an issue with the transmission shifting/solenoid. I cleared the code and will go for a drive later to see if it manifests again. From what I've read, this issue has occurred for several others and usually is caused by the internal injectors which cause the transmission to change gears. As the Skyactiv transmissions are sealed, I cannot check the fluid. My only theory is that I washed the inside of the wheel arches with a coin op wand. Perhaps water got into something? I didn't hold the spray in any spot too long (maybe 2-3 seconds per wheel) but who knows.

Any advice? If I get the light again I'm going to the dealer as the powertrain coverage is still in effect.

[morganc]

You've probably done nothing wrong with your pressure washing. It could be a random flake of metal, or some gasketing material that has finally come loose from original production. It could just be a failed solenoid altogether. Don't clear it next time, definitely hit up that warranty!

Driving home from the grocery store this afternoon I was waiting to turn right on a red light. I began coasting forward without any throttle and looked down to see my Traction Control light was illuminated. There was no reason for TC system to be active obviously. I tried turning off the TC system with the button to no avail. As I began to accelerate the car wouldn't shift to 2nd even when I put it into manual mode (I got the "M" but no gear indication and then the AT light came on). I pulled off immediately and tried shutting off the engine and re-starting it. All went fine but the check engine light stayed on. No issues shifting on the way home. The code I got is a P0470 which indicates an issue with the transmission shifting/solenoid. I cleared the code and will go for a drive later to see if it manifests again. From what I've read, this issue has occurred for several others and usually is caused by the internal injectors which cause the transmission to change gears. As the Skyactiv transmissions are sealed, I cannot check the fluid. My only theory is that I washed the inside of the wheel arches with a coin op wand. Perhaps water got into something? I didn't hold the spray in any spot too long (maybe 2-3 seconds per wheel) but who knows.

Any advice? If I get the light again I'm going to the dealer as the powertrain coverage is still in effect.

[Dreamliner]

I went for a drive tonight (maybe 5km) and no lights illuminated again. If I bring the car in I'll still have to pay the ridiculous charges to "diagnose" the issue. Tomorrow I'll take the car on the highway and see if anything happens.