U0250: Lost Communication With Impact Classification System Module

What it means

A control module has stopped receiving expected messages from the impact classification system module. The code identifies the communication loss; it does not establish what safety functions or inputs this module handles on a particular vehicle.

At a glance

• Usually lights the warning light of the system that lost communication

How it works

The impact classification system module sends information to other vehicle modules over the communication network. U0250 sets when a receiving module stops getting its expected messages; the code alone does not establish which inputs or restraint functions this module handles on a particular vehicle.

Common causes

Most likely first.

1. Loss of power or ground to the module
2. Open, shorted, or damaged network wiring or connector
3. Failed module

Symptoms

• An airbag or restraint-system warning may appear
• Impact-classification functions may be unavailable

How to diagnose it

1. Scan the restraint and other vehicle modules, record freeze-frame and related codes, and identify which module reports U0250.
2. Check for an airbag or restraint warning and review vehicle-specific service information to understand the impact classification system's role.
3. Inspect the module connector and accessible network wiring for damage, corrosion, moisture, or loose connections, without probing restraint-system circuits.
4. Have module power and ground checked using the manufacturer's restraint-system safety procedure.
5. Test the communication wiring for opens or shorts using the manufacturer’s procedure and wiring diagram.
6. If the circuit and supplies are correct, follow the manufacturer's restraint-system diagnostic process before considering module replacement.

Common fixes

• Secure a loose network connector if the manufacturer's safety procedure permits.
• Repair damaged network wiring or connector terminals using the specified restraint-system procedure.
• Restore a faulty module power feed or ground after confirming the fault.
• Replace or configure the impact classification system module only as directed by vehicle-specific service information.

Can I keep driving?

If an airbag or restraint warning is on, some safety functions may be impaired, and the code does not reveal which ones. Arrange prompt diagnosis and avoid disturbing restraint-system wiring; follow the vehicle's guidance on whether to drive.