U0238: Lost Comms with Digital Audio Control Module D
The U0238 code indicates that the vehicle's main control module (typically the PCM or gateway module) has lost communication with the Digital Audio Control Module D (DACM D). This module manages infotainment functions such as digital audio processing, user interfaces, and multimedia connectivity. Communication occurs over multiplexed data buses like CAN, LIN, or MOST, depending on the vehicle architecture. The loss of communication may be intermittent or permanent, and the module can be located in the head unit, an audio amplifier, or a separate sound processor module.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Faulty Digital Audio Control Module D (DACM D)
- Open, shorted, or damaged wiring in the communication bus (CAN/LIN/MOST)
- Corroded, loose, or disconnected connector at the audio module
- Failed network bus terminator or termination resistor
- Low voltage or power supply failure to the audio module
- Electromagnetic interference on the communication wiring
- Corrupted software or need for firmware update in the audio module
- Faulty master control module that manages the communication bus
3. Symptoms You Will Notice
- No audio from speakers or intermittent audio loss
- Infotainment screen frozen, blank, or unresponsive
- Bluetooth, USB, or auxiliary input not working
- Error messages related to audio system on the display
4. Step-by-Step Diagnosis
Scan for other related communication codes (U-codes) to identify the scope of the issue.
Inspect the DACM D connector for corrosion, bent pins, or looseness; clean and secure as needed.
Check the communication bus wiring (CAN/LIN/MOST) for opens, shorts, or damage using a multimeter or oscilloscope.
Verify power and ground at the DACM D module (should be battery voltage with key on).
Test the network termination resistors (typically 60 ohms on CAN bus) at the module or bus ends.
If wiring and power are good, attempt to reprogram or update the DACM D software; if that fails, replace the module.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive. The U0238 code only affects the audio/infotainment system and does not impact engine, transmission, or safety systems. However, you may lose audio and some convenience features.
How much does it cost to fix?▼
Diagnosis typically costs $100-$150. Repair costs vary widely: a simple connector fix may be under $100, while replacing a DACM module can range from $300 to $800 including labor, depending on the vehicle and module location.