Fix U0125: Mechanic’s solutions that WORKED

The code U0125: Lost Communication with Multi-Axis Acceleration Sensor Module points out a fault in communication with the multi-axis acceleration sensor module, which is integral for certain safety and stability functions in modern vehicles. This issue is most likely caused by a failure in the sensor module itself, issues in the vehicle’s communication network, or problems with related control modules.

U0125 quick overview

Meaning	U0125: Lost Communication with Multi-Axis Acceleration Sensor Module
Is it serious?	This code indicates a communication issue, which can be serious depending on the vehicle’s safety features relying on the sensor.
Possible causes	– Faulty multi-axis acceleration sensor module – Damaged or corroded wiring/connectors in the communication network – Faulty control module – CAN bus communication issues
How to diagnose?	Inspect Wiring and Connectors: Check for any visible damage, corrosion, or loose connections in the communication network. Test Sensor Module: Verify the functionality of the multi-axis acceleration sensor module. Check Control Modules: Inspect other related control modules for faults or communication errors. Use Diagnostic Scanner: Utilize a scanner to diagnose communication issues within the CAN bus system.

How to fix U0125 – learn from mechanics

I looked into U0125 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Chrysler

Vehicle Information: 2005 Chrysler 300 Limited 3.5L

Issue + Repair History:

• Vehicle presented codes C2114 and U0125.
• Power wires to ABS module load tested and found to be good.
• Voltage drop detected in power wire to G sensor upon connection.
• Consultation with Chrysler technicians provided no resolution.

Other OBD2 Codes + Test Results:

• C2114 and U0125 were the primary codes noted.

Suggestions to Fix Issue:

• Load test supply and ground wires.
• Consider potential issues with wiring, ABS module, or dynamic sensor.
• Check for a possible short in the G sensor or damage to the ABS module circuit.

Final Fix:

• The root cause was both toner rings on the rear axle rusted, assumed to be due to the vehicle sitting. The issue emerged after the vehicle was in a body shop for a dent repair. Repairing the toner rings resolved the problem.

Case #2: Cadillac

Vehicle Information: 2010 Cadillac SRX Performance 3.0L

Issue + Repair History:

• Service Stabilitrac message and traction off light on.
• Multiple DTCs including C0710, U0074, U0125, U0126; cleared but returned upon driving.
• Initial no communication with steering angle sensor; replaced but issue reoccurred.
• Later, no communication with both steering angle sensor and yaw sensor.
• Found rear differential control module unplugging restored communication.
• Replaced rear differential module, configured at GM dealer, temporarily resolved issue.
• Customer reported intermittent return of Stabilitrac message.
• New codes: U0073, U0074, U0125-72, U0125-74, U0126-72.
• Restarting vehicle temporarily cleared message and codes.

Other OBD2 Codes + Test Results:

• C0710, U0074, U0125, U0126, U0073, U0125-72, U0125-74, U0126-72

Suggestions to Fix Issue:

• Check wiring and terminal connections.
• Consider potential ECM or sensor issues.
• Inspect for possible shorts or loose terminals in the wiring harness.

Final Fix:

• Traced issue to short in high-speed data lines and loose terminals in connector X202.
• Replaced female terminals in connector X202 and terminal for circuit 6105 in steering angle sensor connector.
• Resolved intermittent communication issues.

Case #3: Jeep

Vehicle Information: 2008 Jeep Wrangler Unlimited X 3.8L

Issue + Repair History:

• ABS/traction control lights on.
• Initially diagnosed with U0125 code in ABS, indicating no messages received from dynamics sensor.
• Found no power from ABS module to the dynamics sensor, despite good continuity in the wiring.
• Bypass wire run for the dynamics sensor initially seemed to fix the issue, but then C2200 code (ABS module internal failure) appeared.
• After cutting the new wire, the U0125 code returned without C2200.
• Wire showed no shorts, suggesting a possible ABS module fault.

Other OBD2 Codes + Test Results:

• Initially: U0125
• After repair attempt: C2200, then back to U0125

Suggestions to Fix Issue:

• Verify integrity and continuity of wiring to dynamics sensor.
• Check for any possible shorts or faults in the wiring or sensor.
• Consider potential ABS module issues, especially after additional load from the sensor.

Final Fix:

• After persistent troubleshooting, the ABS module was replaced, resolving the issue.

Case #4: GMC

Vehicle Information: 2016 GMC Yukon 6.2L

Issue + Repair History:

• Experienced loss of communication with the Multi Axis Acceleration Sensor, Electronic Brake Control Module, and the Airbag Diagnostic Module.
• Suspected damage to CAN wiring during modification for handicap access.
• Faced difficulties due to using 2014 wiring diagrams and limited scanner access.
• Initially, no specific faults found in wiring or modules.

Other OBD2 Codes + Test Results:

• U0432
• U0151
• U0125

Suggestions to Fix Issue:

• Advised to recheck all basics, especially fuses and wiring.
• Considered possibility of inadvertently damaging a wire or connector during modification work.
• Suggested to ensure all fuses were properly tested and connected.

Final Fix:

• The problem was a blown fuse that was initially overlooked. The issue was resolved by replacing the fuse after thorough rechecking of the basics, as suggested by community members.

Case #5: Ford

Vehicle Information: 2012 Ford Transit Connect XLT Premium 2.0L

Issue + Repair History:

• Original issue: ABS and traction light on, front wheel bearings bad and grinding.
• Replaced front wheel bearings.
• Post-repair: Persistent C0034:15 code (RF Wheel Bearing Short to Battery or Open).
• Extensive diagnostic tests conducted.
• Replaced ABS Module/HCU.
• Additional U0125:88 code (Lost Communication with Axis Acceleration Sensor Module) appeared post-repair.
• Attempted sensor relearning unsuccessful due to U code.

Other OBD2 Codes + Test Results:

• C0034:15 (RF Wheel Bearing Short to Battery or Open)
• U0125:88 (Lost Communication with Axis Acceleration Sensor Module)

Suggestions to Fix Issue:

• Recheck all electrical connections and wiring integrity.
• Re-examine replaced components for defects.
• Suggested exploring potential issues unrelated to initial repair, like sensor communication problems.

Final Fix:

• The cause of the ongoing issue was not explicitly stated in the provided information.

Advice	Description of Diagnostic Step
Check Wiring and Connectors	Examine wiring and connectors for damage, corrosion, or loose connections.
Verify Sensor Communication	Ensure sensors related to the code communicate properly with the control module.
Inspect Related Modules	Check other related modules for faults or communication errors.
Review Previous Repairs	Revisit recent repairs that might have affected the system.
Use Diagnostic Equipment	Utilize diagnostic tools for investigation and pinpointing the cause.