Codes U1110 and U 1120

2007 JEEP LIBERTY
157,000 MILES • 3.7L • VR6 • 2WD • MANUAL
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LUISEPC20
  • MEMBER
  • 1 POST
Warning lights came on for ABS/brake/stability control/etc., and the speedometer and tachometer stopped working. I replaced the battery. Did not fix problem. Showing error codes U1110 and U1120.
Oct 22, 2019 at 8:57 AM
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STEVE W.
  • ASE Certified Mechanic
  • 15,200 POSTS
  • ASE Certified Mechanic
Welcome to 2CarPros. Those are both communication error codes. U1110 means the PCM didn't receive a vehicle speed signal from the Anti-lock brake Module. U1120 is a lost wheel distance message. These can be caused by a bad or damaged wiring harness to the ABS module or by a failing power-train control module. I would start by looking at the connections on the ABS module for corrosion or water damage as well as looking the harness over for any rodent or physical damage. These signals are carried on the CAN C communications buss and a short in that line can set these codes as well as stop the speedometer and tachometer from working. To test that you would need a factory scan tool that can look at the networks and see if it has the correct signal and which modules are active.
Oct 23, 2019 at 7:34 AM
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