The Digital Audio Control Module (DACM) is an electronic control module used on applicable vehicles to manage or participate in digital audio and infotainment functions. Depending on the manufacturer and vehicle architecture, the DACM may communicate with the radio, infotainment system, amplifier, display, Bluetooth system, navigation system, or other multimedia modules.
The exact function of a DACM is manufacturer-specific. Some vehicles may use a separate Digital Audio Control Module, while other vehicles may integrate similar functions into the radio, infotainment head unit, amplifier, or another multimedia module.
A DACM should not automatically be considered the same component as the radio or audio amplifier. The physical design and responsibilities of the module vary between vehicle manufacturers and model years.
What Is a Digital Audio Control Module?
A Digital Audio Control Module (DACM) is an electronic module that participates in the control and processing of digital audio-related functions on vehicles equipped with this architecture.
The module may receive information from other vehicle modules and exchange digital messages through the vehicle communication network. Depending on the system, it may control or coordinate audio sources, multimedia commands, communication with other infotainment modules, or other digital entertainment functions.
The exact functions should always be confirmed using the vehicle-specific wiring diagram and service information.
What Does DACM Stand For?
DACM stands for Digital Audio Control Module.
Some vehicles identify more than one DACM within their electronic architecture. Diagnostic trouble codes may therefore identify the modules using letters such as DACM-A or DACM-B.
DACM-A vs. DACM-B
DACM-A
Digital Audio Control Module A is one electronic module identity used by applicable vehicle architectures.
A communication failure involving this module can generate U0193 on vehicles using the standardized designation.
DACM-B
Digital Audio Control Module B is another module identity used by applicable vehicle architectures.
A communication failure involving this module can generate U0194.
The presence of A and B in the diagnostic code does not necessarily mean that every vehicle contains two separate physical DACM units. Always verify the actual vehicle architecture.
DACM Functions
Depending on the vehicle, a Digital Audio Control Module may perform or participate in functions such as:
- Digital audio processing.
- Audio source management.
- Communication with infotainment systems.
- Communication with audio amplifiers.
- Multimedia control functions.
- Bluetooth-related audio functions on applicable systems.
- Communication with displays or navigation systems on applicable vehicles.
- Exchange of audio-related information through the vehicle communication network.
Not every DACM performs all of these functions. The exact responsibilities depend on the manufacturer, model, year, trim level, and infotainment configuration.
DACM Location
The location of the Digital Audio Control Module varies considerably between vehicles.
Depending on the vehicle, it may be installed:
- Behind the dashboard.
- Behind or near the radio.
- Inside the center console.
- Behind the glovebox.
- Near an audio amplifier.
- Inside the passenger compartment.
- In another location within the infotainment system.
- Integrated into another multimedia assembly.
There is no universal DACM location. Use the vehicle-specific service information before removing interior panels or disconnecting the module.
DACM vs. Radio vs. Audio Amplifier
DACM
A digital audio control module responsible for specific electronic and communication functions within the vehicle's audio architecture.
Radio / Infotainment
The primary user interface for many audio and multimedia functions. It may be a separate module or may integrate functions performed by other modules.
Audio Amplifier
An amplifier increases the electrical audio signal used to drive speakers. It may be separate from the DACM or integrated into another audio assembly.
These components can communicate with each other, but they are not automatically the same component. Correct identification is important before diagnosing or replacing an audio module.
DACM Power Supply
Like other electronic control modules, a DACM requires the appropriate electrical power and ground circuits to operate.
Depending on the vehicle, the module may have:
- Battery power.
- Ignition or accessory power.
- Module wake-up or enable circuits.
- Ground circuits.
- Communication circuits.
A missing power supply or ground can make the DACM appear to have a communication failure even when the communication wiring itself is functioning correctly.
DACM Fuse
The Digital Audio Control Module may receive power through one or more fuses. Fuse location and fuse designation vary by vehicle.
The applicable fuse may be located in the:
- Interior fuse box.
- Instrument-panel fuse box.
- Engine-compartment fuse box.
- Other vehicle-specific power distribution location.
Possible fuse labels include AUDIO, RADIO, MEDIA, INFOTAINMENT, or another manufacturer-specific designation.
There is no universal DACM fuse number. Always use the fuse diagram for the exact vehicle.
Fuse Inspection
- Locate the correct fuse using the vehicle fuse diagram.
- Verify the fuse rating.
- Inspect the fuse for an open element.
- Measure voltage at the fuse when appropriate.
- Inspect the fuse terminals for corrosion or overheating.
- Investigate the cause if a replacement fuse fails again.
Never install a higher-rated fuse to overcome a repeatedly blown fuse.
DACM Communication Network
The Digital Audio Control Module communicates with other electronic modules through the vehicle's communication architecture.
Depending on the vehicle, the communication path may involve CAN, a gateway module, another network technology, or a combination of networks.
A communication failure can therefore be caused by the DACM itself, its power supply, its ground, the communication wiring, a gateway, or another module affecting the network.
DACM Diagnostic Signal Flow
↓
Fuse / Power Distribution
↓
DACM Power & Ground
↓
Digital Audio Control Module
↓
Vehicle Communication Network
↓
Gateway / Related Modules
↓
Radio / Infotainment / Audio System
DACM Signal Flow
↓
Digital Audio Processing
↓
DACM Control Functions
↓
Communication Network
↓
Related Audio Modules
↓
Amplifier / Speakers / Infotainment Functions
The exact signal path varies by vehicle. The diagram represents a general diagnostic concept rather than a vehicle-specific wiring diagram.
Common DACM Symptoms
- Loss of audio.
- Intermittent audio operation.
- Radio or infotainment malfunction.
- Bluetooth audio problems on applicable vehicles.
- Missing multimedia functions.
- Audio source unavailable.
- Display or infotainment communication problems.
- Network communication DTCs.
- DACM unavailable during a diagnostic scan.
- Multiple infotainment-related U-codes.
Symptoms depend on the functions assigned to the DACM in the specific vehicle.
How to Diagnose a DACM Problem
1. Perform a Complete Vehicle Scan
Scan all available control modules and record every stored, pending, and history code.
Pay particular attention to communication codes because another module may report the loss of communication with DACM.
2. Check System Voltage
Check battery and charging-system condition before performing detailed module diagnosis. Low or unstable system voltage can cause multiple electronic modules to become unavailable.
3. Check the DACM Fuse
Verify the correct fuse, fuse rating, and electrical supply using the vehicle-specific fuse diagram.
4. Test Power and Ground
Verify all required DACM power feeds and grounds. Use voltage-drop testing where appropriate to identify excessive resistance.
5. Inspect Connectors
Check the DACM connectors for:
- Corrosion.
- Water intrusion.
- Bent pins.
- Loose terminals.
- Damaged locking mechanisms.
- Previous wiring repairs.
6. Check Communication Wiring
Inspect the applicable communication circuits for opens, shorts, high resistance, damaged insulation, and poor connector contact.
7. Check Related Modules
Check the radio, infotainment system, amplifier, gateway, display, and other related modules for communication codes.
If several modules become unavailable simultaneously, investigate the common network or power supply before replacing the DACM.
8. Test the DACM
If power, ground, connectors, and communication circuits are correct but the module remains unavailable, the DACM itself may have an internal fault.
DACM Multimeter Testing
A digital multimeter can be used to perform several basic electrical checks on a DACM circuit.
Power Test
- Set the meter to DC voltage.
- Connect the negative probe to a known-good ground.
- Measure the DACM battery supply.
- Measure ignition or accessory supply when applicable.
- Compare the readings with manufacturer specifications.
Ground Test
Perform a voltage-drop test across the DACM ground circuit while the system is operating under the appropriate conditions.
Use the manufacturer's specified maximum voltage drop rather than applying one universal value to every vehicle.
Communication Circuit Test
If the vehicle uses CAN communication, a multimeter can provide preliminary voltage information. Typical high-speed CAN reference levels are approximately 2.5 V recessive, with CAN-H and CAN-L moving toward approximately 3.5 V and 1.5 V during dominant signaling.
These are typical reference values only. Always follow the manufacturer's test procedure.
DACM CAN-Bus Resistance Test
On a properly terminated high-speed CAN network, resistance between CAN-H and CAN-L may be approximately 60 Ω with the vehicle powered down according to the manufacturer's procedure.
This commonly results from two 120 Ω termination resistors connected in parallel.
However, not every vehicle network uses the same architecture. A different resistance reading does not automatically prove that the DACM is defective.
DACM Oscilloscope Testing
An oscilloscope can be used to inspect communication waveforms when a network fault is suspected.
For a high-speed CAN network, CAN-H and CAN-L should exhibit complementary transitions during communication.
CAN-L ‾‾\__/‾‾\__/‾‾\__/‾‾\__/‾‾
A flat signal, distorted waveform, excessive noise, incorrect voltage levels, or abnormal transitions can indicate a network or electrical problem. The waveform must be compared with the manufacturer's specifications and the network conditions.
DACM OBD Live Data
A professional scan tool may provide information such as:
- DACM communication status.
- Module availability.
- System voltage.
- Network status.
- Audio-related parameters.
- Infotainment status.
- Communication-related diagnostic information.
Live Data should be combined with electrical testing. A module may appear unavailable because of a power or communication problem rather than an internal module failure.
DACM Software and Programming
Some Digital Audio Control Modules may require software configuration, programming, initialization, or other setup procedures.
Software-related problems can occur after certain module replacements, programming interruptions, configuration changes, or other manufacturer-specific events.
Programming requirements are vehicle-specific. Do not assume that every replacement DACM requires the same programming procedure.
DACM Replacement
A DACM should normally be replaced only after external causes have been eliminated.
Before replacing the module, verify:
- Correct fuse condition.
- Correct power supply.
- Good ground.
- Correct connector condition.
- Communication circuit integrity.
- Network condition.
- Correct module identification.
- Programming or configuration requirements.
A replacement module may require programming, configuration, initialization, or security-related procedures depending on the vehicle.
Common DACM Diagnostic Mistakes
- Replacing the DACM before checking its fuse.
- Assuming the DACM is the same component as the radio.
- Assuming every DACM contains an audio amplifier.
- Failing to check power and ground.
- Ignoring low system voltage.
- Ignoring connector corrosion.
- Replacing the module without scanning other control modules.
- Assuming every communication fault is caused by the DACM.
- Applying one universal CAN specification to every vehicle.
- Installing a replacement module without checking programming requirements.
Related DTCs
- U0193 – Lost Communication With Digital Audio Control Module A.
- U0194 – Lost Communication With Digital Audio Control Module B.
U0193 and U0194 are the directly related DTCs for the DACM A/B identification used by applicable vehicles. Additional radio, amplifier, infotainment, or network communication codes may also be present depending on the vehicle architecture.
Is a DACM Failure Serious?
A DACM fault is generally associated with audio and infotainment functions rather than basic engine operation. However, severity depends on how the manufacturer integrated the module into the vehicle network.
If several control modules report communication faults at the same time, the problem should be investigated as a possible broader network or power-supply issue.
Can You Drive With a DACM Fault?
If the fault is isolated to the audio system and the vehicle operates normally, driving may generally remain possible.
However, if the DACM fault is accompanied by multiple network codes, warning indicators, or other electronic-system failures, the vehicle should be diagnosed promptly.
DACM Repair Cost
- Electrical diagnosis: approximately $50–$150+.
- Fuse or power repair: approximately $20–$150+.
- Wiring or connector repair: approximately $50–$300+.
- Used DACM: approximately $50–$300+.
- New or remanufactured DACM: approximately $150–$800+.
- Programming or configuration: additional cost may apply.
These are general estimates only. Actual cost depends on the vehicle, module design, parts availability, labor rates, and programming requirements.
FAQ About Digital Audio Control Module
What does DACM stand for?
DACM stands for Digital Audio Control Module.
Is DACM the same as a radio?
Not necessarily. The DACM and radio may be separate modules, or their functions may be integrated into the same assembly depending on the vehicle.
Does every vehicle have a DACM?
No. DACM is a manufacturer-specific module designation used on applicable vehicle systems. Other vehicles may integrate similar functions into the radio, infotainment system, amplifier, or another control module.
What causes a DACM communication fault?
Common causes include loss of power, poor ground, blown fuse, damaged wiring, connector problems, communication-network faults, low voltage, software/configuration problems, and internal module failure.
Can a multimeter test a DACM?
Yes. A multimeter can test power supplies, grounds, voltage drops, fuses, and some communication-circuit conditions. More advanced network diagnosis may require an oscilloscope or professional scan tool.
Does a DACM need programming after replacement?
Some vehicles require programming, configuration, initialization, or calibration after replacement. The exact procedure is manufacturer- and vehicle-specific.
Final Takeaway
The Digital Audio Control Module (DACM) is an electronic module used on applicable vehicles as part of the digital audio and infotainment architecture.
It should not automatically be confused with the radio, infotainment head unit, or audio amplifier because the relationship between these components varies by manufacturer and vehicle.
When diagnosing a DACM communication problem, the correct approach is to check the fuse, power supply, ground, connectors, communication wiring, network condition, system voltage, and related modules before condemning the DACM itself.
The two directly related communication codes are U0193 for Digital Audio Control Module A and U0194 for Digital Audio Control Module B.
Always identify the exact vehicle architecture before testing or replacing a Digital Audio Control Module.