U024A: Lost Communication With Interior Lighting Control Module A

What it means

A control module has stopped receiving expected messages from interior lighting control module A. The code identifies the communication loss; lighting functions controlled by the module may be affected.

At a glance

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

How it works

Interior lighting control module A operates the cabin lighting functions assigned to it and communicates status with other vehicle modules over the network. U024A sets when expected messages from module A stop arriving, potentially limiting the interior lights it controls.

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

• Interior lighting functions controlled by the module may be unavailable or limited
• A warning may appear depending on the vehicle

How to diagnose it

1. Scan all modules for communication codes and check event data for other faults on the network used by interior lighting module A.
2. Check the cabin lighting functions assigned to module A and note any interior lighting warning or failure.
3. Inspect module A's connectors and wiring for loose terminals, corrosion, moisture, or damage.
4. Check the module's power and ground circuits according to the manufacturer's procedure.
5. Test the network wiring to interior lighting control module A for opens, shorts, and poor connections using the wiring diagram.
6. If supplies and network wiring pass, follow manufacturer diagnostics to determine whether module A has failed.

Common fixes

• Reconnect or clean a loose or corroded module A connector.
• Repair damaged network wiring or connector terminals serving interior lighting control module A.
• Restore the module's power or ground supply.
• Replace interior lighting control module A if the circuits pass and diagnostics confirm internal failure.

Can I keep driving?

Driving is generally possible if exterior lights and required vehicle systems work normally, but cabin lighting controlled by module A may be unavailable. Avoid relying on those lights to see or operate controls while driving.