Q: U0121 can abs brake unit all dash lights on stalls in reverse

asked by on

Yesterday all my indicator lights lit up on dash board and car stalls when put into reverse. I have some mechanical experience so I popped the hood to take a look and saw a male wire harness hanging down near fan . When I picked it up I saw that a female harness was plugged in but with no wires out of the back. You can look at this part by googling 1j0973802. This harness is used in all types of applications throughout car. I looked around for loose wires or a place to plug to no avail. I took it to auto zone and had them scan it with a generic scanner and got code u0121 which is can abs brake unit. Today I pulled that entire side of engine compartment out and searched and searched but see no wires this could attach to. The cars speedo Odom. And auto Windows don't work, you have to hold buttons instead of just pushing once. Also gas gauge is going haywire as its digital. I had been testing fuses in relation to Ac before this took place but I'm lost to where this could go and I'm broke

My car has 87000 miles.
My car has an automatic transmission.

ABS control unit failures are pretty common on these cars, and cause several warning lights to illuminate when they fail, as well as set faults in almost every control module in the car. Based on the information provided, it’s very likely this is whats happening to you. A qualified technician, such as one from YourMechanic, can verify the diagnosis of the ABS problem. As far as the fuel gauge issue, this could be caused by the faults set in the instrument cluster control module, so I would suggest clearing the faults in all the modules after repairing the ABS issue, and see if the problem still exists after. If it still exists after, it could be a problem with the fuel level sensor. And finally, as far as the windows buttons go, it sounds like the car lost voltage at some point, and the window motors lost their learned positions. This is simple to fix, you just need to reset the window positions. You do this by holding the window button up until the window is closed, then let go, then immediately pull up on the window switch again for 3 seconds. Do this to each window. Now the one touch feature should work.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. U0121 can abs brake unit all dash lights on stalls in reverse

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Van stalls after raining

This problem may take some additional diagnosis by spraying the engine harness and sensors with water like the crankshaft sensor connector may be letting in water and will stall the motor.

Q: Every time I turn my steering wheel left, my BMW ABS light flashes and the car stutters and loses all power

Hi, thanks for writing in. Your car ABS system is equipped with wheel speed sensors which monitor wheel speed and relays this information to the computer which tells the ABS system how to react when the car is out of...

Q: Gasoline smell in car when I fill gas tank

The tank seal where the fuel pump is inserted may be leaking or the vent hoses as well. Typing your year model and vent hose schematic into a search engine shows a few pretty detailed listings of what you're looking...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.