U0189 — Lost Communication With Digital Disc Player/Changer Module "C"

OBD2 code U0189 flags a problem with the vehicle network (CAN bus) communication (lost communication with digital disc player/changer module "C"). Short, gentle driving to a shop is usually possible. Common culprits: poor grounds or low battery voltage, water ingress in harness junctions, damaged CAN bus wiring or short to power/ground.

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

Read the code and freeze frame Connect an OBD2 scanner, confirm U0189 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
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.
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.
Subsystem check Measure resistance between CAN-High and CAN-Low at the OBD port with power off — about 60 Ω is healthy.
Subsystem check Scan all modules: the one that does not respond is either the culprit or downstream of the break.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0189 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for U0189 (parts and labor, USD, independent shop rates): Replace the faulty control module: $300–$1,500; Remove interfering aftermarket device: $0–$150; Repair CAN wiring or connectors: $100–$400. Overall, fixing U0189 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

Will U0189 clear itself?

Sometimes U0189 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.

What are the symptoms of U0189?

Drivers most often notice: intermittent loss of functions (gauges, windows, steering assist), multiple warning lights on at once, modules intermittently not communicating with the scanner, no-start or intermittent starting in some cases.

What does OBD2 code U0189 mean?

What is the most common cause of U0189?

The most common causes are: poor grounds or low battery voltage, water ingress in harness junctions, damaged CAN bus wiring or short to power/ground.

Is it safe to drive with U0189?

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.

What does U0189 mean?

U0189 is logged by the onboard diagnostics when the vehicle network (CAN bus) communication does not behave as expected. The official definition is “Lost Communication With Digital Disc Player/Changer Module "C"”. This is a vehicle network category code.

This code does not appear from a single bad reading: the module must see the fault condition repeat under defined operating conditions before it turns on the warning light. The freeze frame captured with U0189 — engine load, rpm, temperature, speed — tells you exactly when the problem occurs, so reproduce those conditions when testing.

Common symptoms of U0189

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

What causes U0189?

damaged CAN bus wiring or short to power/ground
a faulty module pulling the bus down
aftermarket equipment interfering with the bus
water ingress in harness junctions

How to diagnose U0189

Connect an OBD2 scanner, confirm U0189 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
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.
Visually inspect the wiring harness and connectors related to the vehicle network (CAN bus) communication for damage, corrosion, chafing or poor contact.
Measure resistance between CAN-High and CAN-Low at the OBD port with power off — about 60 Ω is healthy.
Scan all modules: the one that does not respond is either the culprit or downstream of the break.
Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0189 does not return.

How to fix U0189

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

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

How much does it cost to fix U0189?

Repair cost depends on which component actually failed. Typical scenarios for U0189 (parts and labor, USD, independent shop rates):

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

Overall, fixing U0189 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.