Abs help

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Welcome new members, please make your first post in this section. Say hello & tell us a little bit about you and your car. We're happy to see you here!
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Kylerhcarlisle
Posts: 1
Joined: Sat Nov 21, 2020 1:39 pm

Abs help

Post by Kylerhcarlisle »

I have been working on the abs brake for weeks now have ran new grounds and I have voltage at my abs module have replaced the module twice and I still get the same code U0121 lost communication abs module, please help!!
2012 chevy caprice 6.0 l77
smwalker
Administration Staff
Posts: 2203
Joined: Mon Jul 29, 2013 1:44 am
Location: Azusa,CA

Re: Abs help

Post by smwalker »

What you would want to do is hook up a scanner and see if you can communicate with the module. If not then would want to look for a break in the data lines. Most likely a bad terminal at one of the connectors is usually what we see,

here is the data wires diagram.
https://www.chiltonlibrary.com/content/ ... 662707.pdf
Is this a new problem? Like was it OK before and it popped up or did the car have the problem when you got it?
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
smwalker
Administration Staff
Posts: 2203
Joined: Mon Jul 29, 2013 1:44 am
Location: Azusa,CA

Re: Abs help

Post by smwalker »

Here is a diagnosis on a jeep but similar tasks to do:
Part 1
https://www.youtube.com/watch?v=vMRY8l3ivNE
Part 2
https://www.youtube.com/watch?v=ihLc4d21lBE
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
smwalker
Administration Staff
Posts: 2203
Joined: Mon Jul 29, 2013 1:44 am
Location: Azusa,CA

Re: Abs help

Post by smwalker »

Oh and just to clarify. you are programming the ABS module each time you install it correct?
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
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