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Brad, Jeep Dealership Tech
Category: Jeep
Satisfied Customers: 7993
Experience:  19 Yrs Chrysler/Dodge/Jeep. ASE Master (L-1) Certified
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I have A 2005 jeep Grand Cherokee Laredo and my Lights on

Customer Question

I have A 2005 jeep Grand Cherokee Laredo and my Lights on dash started coming on last week:
Check Engine
Display showing Service Electrical Brake System
Took it in and was they ran diagnosis that concluded I need a new ABS module and recommended replacing some main electrical wire. The cost is out of my budget at this time so my car is back home where my dad and I are going to try and fix ourselves.
Submitted: 10 months ago.
Category: Jeep
Expert:  Brad replied 10 months ago.

Good afternoon and welcome to JustAnswer!!

My name is ***** ***** I have worked for a Chrysler-Dodge-Jeep dealership for 19 years and I will do my best to help.

What P codes are setting in the PCM and ABS modules? Also unless you have a scantool you will not be able to replace the ABS module if it is in fact faulty..

Talk soon,


Customer: replied 10 months ago.
codes given were
U0121 Lost Communication with Anti-lock brake module
Expert:  Brad replied 10 months ago.

Since all the codes are for no communciation with the ABS module then yes I would replace it.. Do you have a scantool to program it?

Customer: replied 10 months ago.
I have theInnova CANOBD2 diagnostic tool. My dad is an electrical Genius so I was going to take it off and he was going to test and if he can fix it he will.
If he cant fix it what if we find a used one from same vehicle would it still need to be programmed?
If not what other options do I have?
Expert:  Brad replied 10 months ago.

If the ABS module is bad which I suspect it is then I would suggest getting a new one because you don't know if your getting a new part and also it will need to be programmed with a scantool and it sounds like you only have code readers.. We(Dealership) charge 1 hour labor to program modules..

Expert:  Brad replied 10 months ago.

If you need anymore assistance feel free to shoot me a reply and don't forget to RATE before leaving the site so I get credit for helping you today..

Have a great day,