U025D: Lost Communication With Front Controls Interface Module B

What it means

A control module has stopped receiving expected messages from front controls interface module B. The code identifies the communication loss; controls routed through that module may be affected.

How it works

Front controls interface module B handles signals for the controls routed through that specific module and exchanges messages with other vehicle modules. This code sets when a monitoring module stops receiving the expected network messages from module B.

Common causes

Most likely first.

1. Bus wiring open or shorted
2. Module without power or ground
3. Module failed

Symptoms

• Controls routed through the module may be unavailable or limited
• A warning may appear depending on the vehicle

How to diagnose it

1. Record freeze-frame data and scan all modules for communication codes to see whether module B alone is missing or the network has a wider fault.
2. Check which front controls are unavailable or limited and confirm whether this vehicle routes them through front controls interface module B.
3. Inspect module B's connectors and bus wiring for loose plugs, corrosion, damaged pins, chafing, or possible opens and shorts.
4. Check module B's power and ground circuits using the manufacturer's procedure, since a missing supply can stop its messages.
5. If power and ground are correct, test the network circuits at module B for opens or shorts according to the manufacturer's procedure.

Common fixes

• Reconnect or secure a loose connector at front controls interface module B.
• Repair damaged bus wiring or corroded connector terminals serving module B.
• Restore a missing power or ground feed to module B.
• Replace module B if its supplies and network wiring are correct but communication remains absent.

Can I keep driving?

If only nonessential controls routed through module B are affected and the vehicle otherwise operates normally, driving may be possible. Avoid driving if an unavailable control is needed to operate the vehicle safely.