U0238: Lost Communication With Digital Audio Control Module D

What it means

A control module has stopped receiving expected messages from digital audio control module D. The code identifies the communication loss; audio functions routed through that module may be affected.

At a glance

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

How it works

Digital audio control module D handles audio functions assigned to that module in the vehicle’s system. U0238 is set when another module no longer receives expected network messages from module D; the code does not by itself identify an audio component failure.

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

• Audio functions routed through the module may be unavailable
• A communication fault may be stored; a warning may appear depending on the vehicle

How to diagnose it

1. Use a scan tool to record freeze-frame data and check whether U0238 is current or accompanied by communication codes for other audio modules.
2. Check which audio functions are unavailable and whether the fault changes when the audio system is switched on.
3. Inspect module D’s connector and accessible network wiring for looseness, corrosion, water intrusion, or damage.
4. Check the module’s power and ground using the manufacturer’s wiring information.
5. Test the network wiring to digital audio control module D for opens or shorts following the manufacturer’s procedure.
6. If its supplies and network wiring pass, use the manufacturer’s diagnostic procedure to confirm whether module D has failed.

Common fixes

• Reconnect or repair a loose or corroded connector at digital audio control module D.
• Repair damaged network wiring to module D.
• Restore the module’s power or ground connection.
• Replace digital audio control module D if circuit tests confirm an internal failure.

Can I keep driving?

Driving is generally unaffected, but audio functions routed through module D may be unavailable. If the fault coincides with other electrical or warning-system problems, have those symptoms assessed as well.