Jeep liberty codes

Have you checked the connectors in the wiring harnesses for the ABS unit and associated components for water intrusion or corrosion?

The codes that you've posted (details below) all point to a poor electrical connection in the circuit(s) or an open or short in the circuit(s). That could be either due to corrosion, liquid intrusion, a wiring harness rubbing against something hot or something that vibrates and has damaged the wiring.

If the wiring and connections are all intact and there are no opens, shorts to power or shorts to ground, the next think to look at would be the modules and/or sensors to make sure they're operating within spec.

U1003 Possible Causes:
*Faulty Anti-lock Brake System (ABS)
*Module Anti-lock Brake System (ABS)
*Module harness is open or shorted Anti-lock Brake System (ABS)
*Module circuit poor electrical connection

The Diagnostic Trouble Code (DTC) sets if the Anti-lock Brake System (ABS) Module fails to receive bus messages from the Dynamic Sensor for approximately 150 ms.

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C0020-1c Possible Causes:
*Faulty Anti-Lock Brake System (ABS) *Control Module Faulty Hydraulic Control Unit (HCU)
*Hydraulic Control Unit (HCU) harness is open or shorted Hydraulic Control Unit
*(HCU) circuit poor electrical connection

The Hydraulic Control Unit (HCU) consists of a valve body, pump motor, and inlet/outlets for the brake lines. The combined HCU and Antilock Brake System (ABS) module is located forward of the master cylinder.

The Anti-Lock Brake System (ABS) Module monitors the ABS Pump Motor. The ABS Module sets the OBDII code when the ABS Pump Motor is not to factory specifications.

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U0125 Possible Causes:
*Faulty Dynamics Sensor Dynamics Sensor
*Harness is open or shorted Dynamics
*Sensor circuit poor electrical connection

The Diagnostic Trouble Code (DTC) sets if the Anti-Lock Brakes System (ABS) Module fails to receive bus messages from the Dynamics Sensor.

possible damaged or improper install--harness short --fuse blown

If you talking about abs/traction control system then each wheel has own speed sensor

scan ABS is next,.
abs errors
or brake actual are bad. and due.

run the fault codes
as all those sensors use the wheel sensors for the ABS ir is possible that there is a wiring problem at one of the wheels

This video is for a liberty, but all Jeeps should be similiar.
Jeep Liberty How to fix Traction ABS EST Light Codes C1240 C123F Also a guy in a forum says that it might involve a recall of the DCX recall applying to ABS modules on many Chrysler, Dodge, & Jeep products including the Commander. I'd call your dealer and ask, they might fix it for free if it's a recall. http://www.jeepcommander.com/forums/5-general-commander-discussion/1483-esp-bas-traction-control-light-staying.html

when repair is done the warning light will reset

you need to make brakes good first. first.
then scan the ABS for errors.
or you will never fix this.
i can make a list of 20 things, what would be the point.
even wrong sized tires.

get it serviced,

Could be bad wheel speed sensor. You need someone with a code reader that reads ABS codes.

It means there is a problem in the abs or traction control system.You have to get the codes to find out what is causing the problem.Your regular brakes will work normally but you will not have abs or traction control.Hope this helps.Good luck.