HELP!!! ECU FAULT CODES P0500 and P0105
 

ABS, check engine light and Traction control slip light on. Car will not go over 4000 RPM. Fan turns on immediately even when in accessory mode (key in the second position, just before starting it). Read the ECU with my OFT and it gave me P0105, then I read it again with a dedicated OBD II reader and it gave me P0500. HELP!!!

I had the same scenario happened to me before! My cluster suddenly lit up and my speedometer dropped to 0 during my way home on the freeway. It was a horrible experience lugging the car home in limp mode as my power steering stopped as well.

If you are experiencing a P0500 CEL, then it has to do something with your vehicle speed sensor. If you had recently messed with your suspension in any way, that may be the cause of your problem. In my case, it was because I was playing around with tire sizes in the rear and was running a sidewall that was too thick, causing it to rub against the rear bumper's plastic liner.

I was able to diagnosis my problem since clearing the code would allow me roughly ~20 minutes of normal driving (no limp mode/speedometer works) before the CEL would pop up again. So this meant that vehicle speed sensor was fine, but something else was causing the problem. After clearing the code, swapping my wheels out for another set, and going for a successful test drive, I was able to confirm that my wheels/tires were the cause.

Try clearing the code and see if it comes back on immediately (like within a few minutes of driving and your speedometer isn't working). If it comes on immediately, your speed sensor must have been damaged. If not immediate and your speedometer works up until your CEL pops up, consider all the suspension components that you may have messed with including wheels/tire.

-My car was recently in an accident and just got repaired.
Rear subframe,drivers side rear suspension and axle were all replaced (rear drivers side quarter panel too)
-My speedometer seems pretty accurate
-Every time I try to clear the code it come back on within 5 seconds.
-In terms of tires, it currently has regular primacy tires on the front and snow tires on the back (with stock rims all around)

Any update?

Took the car in to the dealer. They cleared all the codes. By the time they brought the car back to the front the lights were back on. Went home and got a new speed sensor (on that side that was damaged), installed it and cleared all codes. Lights didn't come back on. Been driving for couple weeks now and everything is fine.

what tire sizes were you running that caused this issue? I'm curious because my new tires are 4.72% in difference and was wondering if this would cause it.