09/06/2026
2020 Chevy Sonic (RS). 1.4L turbo auto. 90K-ish miles?
Customer; “It won’t go when I step on it”.
Test drive; no, no it won’t.
“Stealership” may have recommended an extensive and expensive solution? A new transmission? Or a “valve body”? But not a wiring harness for the body? These noobies…
Yes. CEL is on, “limp mode” third gear start. No reverse. Fault code P1942? Whatever code
Let’s take a minute, or 30; and look.
Just one fault code. The transmission “brain aka computer” is losing a voltage signal… ahh, blown fuse. Replaced, test drive… car shifts through all 5 gears. Plus reverse. Yay! Wtf! Let’s just drive it for a few….
A few days later the customer calls and says, “it’s doing it again!”
Foretold this I may have done. We pondered about the amperage surge that could have overpowered that fuse to begin with…..
Vehicle returns, under its own power. That same fuse was shorted.. hmmm. cue the Law and Order 1-2.
Let’s get back the wire schematic. Fuse feeds all the shfting solenoids IN the mechanical valve body AAAND the “rear view camera”. Oh, and the brake light switch. Brake lights work just dandy. One of three items on that circuit is shorting, causing the fuse to blow.
We knew that that camera had to separated from the equation. I mean, why would a camera be on the transmission valve body wiring circuit? Definitely sounds stoopid from here.
We opened the trunk, removed some trim, and unplugged that little “device”. The “reverse / back up camera” thingamajigger.
(ps; y’all should turn heads and look before, and after you engage) It’s good exercise.
After a few awesome test drives, the has all gears, had its “adaptive shift pattern” reset, and scoots. The customer is educated, advised, and ecstatic.
Always follow the cause, not just the symptoms. Ya gotta be smarter than what you’re working on.
Pps;, Yyyeeahhh, I should narrate these tales… hehehehe. Now hiring a videographer.