OBD-II Standard U0170: OBD-II Standard OBD-II Universal E...

Symptoms

The ABS, traction control, and stability control warning lights are on. These systems may be disabled. DTC U0170 is stored by a control module that lost communication with the Brake Control module.

Possible Causes

CAN bus wiring fault to ABS module
ABS module power supply fault
ABS module internal failure
ABS connector corroded

Troubleshooting Steps

Step 1: Connect a diagnostic scanner and read all module DTCs to confirm U0170
DTC U0170 is present; note which module logged the code
Step 2: Check CAN bus wiring between the affected modules for continuity, shorts, and termination resistor values
CAN high and low lines intact, 60 ohms across the bus
Step 3: Verify power and ground supplies to the affected module
Battery voltage at module power pin, less than 0.1V drop on ground side
Step 4: If wiring is intact, the affected module may need replacement and programming
Communication restored after module replacement and programming

How to Reset

Clear the DTC after repair using a diagnostic scanner. The code will clear automatically if communication is restored and no fault is detected for 3 consecutive drive cycles.

Common Replacement Parts

varies: ABS hydraulic control unit (if confirmed faulty) (Confirm part number via VIN before ordering; programming typically required)

Frequently Asked Questions

Q: What does code U0170 mean?
This is a network communication DTC indicating lost communication with the Brake Control module. The CAN bus wiring, module power supply, and the module itself should be checked.
Q: Can I drive with code U0170?
Driving may be possible but the affected system may not function. If the code relates to ECM, transmission, or brake communication, have it diagnosed promptly for safety.

OBD-II Standard OBD-II Universal Error Code U0170