U0188: Lost Communication with Audio Rear Control Module
The Audio Rear Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. Rear-seat audio controls stop working. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.
What U0188 means
U0188 is a generic OBD-II network code in the lost communication group. In plain English: a control module stopped receiving messages from the Audio Rear Control Module on the vehicle’s data network.
- Check engine light
- Usually off
- Emissions-related
- No
- Limp mode possible
- Not typical
- Drive cycle to clear
- Not required
Get it fixed
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Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
- 01Rear audio module unpoweredMost likely
- 02CAN wiring to rear audio module brokenPossible
- 03Gateway module routing CAN messages incorrectlyLess likely
Can I drive with U0188?
Generally yes.
This fault is unlikely to affect how the car drives. Fix it when convenient.
Why we rate it low
- Does not normally turn on the check engine light
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose U0188
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just U0188. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Fix other faults first
If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.
- 3
Check module power, ground and the data bus
Confirm the module named in the code has battery voltage, ignition feed and a good ground. With the battery disconnected, a healthy CAN bus usually measures about 60 ohms between CAN-High and CAN-Low at the OBD port. Inspect connectors for corrosion and pushed-out pins.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Rear audio module unpowered; CAN wiring to rear audio module broken; gateway module routing CAN messages incorrectly. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.
U0188 repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Moderate
- Good DIY job?
- Usually a shop job
Needs a scan tool and some experience with testing.
Parts and systems involved
- Audio rear control module
- CAN bus wiring
U0188 FAQ
What does U0188 mean?
U0188 means “Lost Communication with Audio Rear Control Module”. The Audio Rear Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. Rear-seat audio controls stop working. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.
Is U0188 serious? Can I keep driving?
We rate U0188 as low severity. Generally yes. This fault is unlikely to affect how the car drives. Fix it when convenient.
What causes U0188?
The most common causes, from most to least likely: Rear audio module unpowered; CAN wiring to rear audio module broken; Gateway module routing CAN messages incorrectly. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix U0188?
Typical labor is about $65–$250 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix U0188 myself?
DIY difficulty is moderate. Most owners leave this to a shop because it needs involved testing or specialist tools. Always confirm the cause before buying parts.
Will U0188 clear itself?
If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.