U0494 — Invalid Data Received From "Digital Audio Control Module A"

vehicle network

Is it safe to drive?

Drive with caution Depends on what is affected. A single dead convenience module is fine to drive with; loss of communication with engine, braking or steering modules is not. If multiple critical systems drop out, do not drive.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm U0494 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many U0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the vehicle network (CAN bus) communication for damage, corrosion, chafing or poor contact.
  4. Subsystem check Measure resistance between CAN-High and CAN-Low at the OBD port with power off — about 60 Ω is healthy.
  5. Subsystem check Scan all modules: the one that does not respond is either the culprit or downstream of the break.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0494 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for U0494 (parts and labor, USD, independent shop rates): Remove interfering aftermarket device: $0–$150; Replace the faulty control module: $300–$1,500; Repair CAN wiring or connectors: $100–$400. Overall, fixing U0494 usually costs between $0 and $1,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What is the most common cause of U0494?

The most common causes are: a faulty module pulling the bus down, damaged CAN bus wiring or short to power/ground, aftermarket equipment interfering with the bus.

Will U0494 clear itself?

Sometimes U0494 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

How do I diagnose U0494 myself?

Start with a scan: confirm U0494, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the vehicle network (CAN bus) communication, and verify the suspect component against live data before buying parts.

How much does it cost to fix U0494?

Remove interfering aftermarket device — $0–$150; Replace the faulty control module — $300–$1,500; Repair CAN wiring or connectors — $100–$400. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What does OBD2 code U0494 mean?

Invalid Data Received From "Digital Audio Control Module A" (U0494): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by a faulty module pulling the bus down, damaged CAN bus wiring or short to power/ground, aftermarket equipment interfering with the bus.

What does U0494 mean?

The engine control module sets U0494 when it detects a fault in the vehicle network (CAN bus) communication. In practical terms: invalid data received from "digital audio control module A". The code belongs to the vehicle network group of OBD2 codes.

The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores U0494 and switches on the warning light. Freeze frame data saved with the code shows the exact conditions — rpm, load, temperature, speed — at the moment the fault was detected, which is the best starting point for diagnosis.

What causes U0494?

  • a faulty module pulling the bus down
  • water ingress in harness junctions
  • poor grounds or low battery voltage
  • aftermarket equipment interfering with the bus

Common symptoms of U0494

  • multiple warning lights on at once
  • intermittent loss of functions (gauges, windows, steering assist)
  • random, hard-to-reproduce electrical glitches
  • no-start or intermittent starting in some cases
  • modules intermittently not communicating with the scanner

How to diagnose U0494

  1. Connect an OBD2 scanner, confirm U0494 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many U0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the vehicle network (CAN bus) communication for damage, corrosion, chafing or poor contact.
  4. Measure resistance between CAN-High and CAN-Low at the OBD port with power off — about 60 Ω is healthy.
  5. Scan all modules: the one that does not respond is either the culprit or downstream of the break.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0494 does not return.

How to fix U0494

Start with the cheapest and most common causes before replacing expensive parts:

  • Remove interfering aftermarket device — $0–$150
  • Replace the faulty control module — $300–$1,500
  • Repair CAN wiring or connectors — $100–$400

How much does it cost to fix U0494?

Repair cost depends on which component actually failed. Typical scenarios for U0494 (parts and labor, USD, independent shop rates):

  • Remove interfering aftermarket device: $0–$150
  • Replace the faulty control module: $300–$1,500
  • Repair CAN wiring or connectors: $100–$400

Overall, fixing U0494 usually costs between $0 and $1,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with U0494?

Depends on what is affected. A single dead convenience module is fine to drive with; loss of communication with engine, braking or steering modules is not. If multiple critical systems drop out, do not drive.

Related OBD2 codes