U18A3
Lost Communication With Human Machine Interface Control Module
U18A3 is an OBD-II diagnostic trouble code meaning: Lost Communication With Human Machine Interface Control Module. Common causes: open or short circuit in the hmi module power supply circuit, damage to the can bus wiring harness. Estimated repair cost: $56–278.
Symptoms
- Controls on the center console do not work
- No image on display
- Malfunctions of the multimedia system
- Dashboard flashing or turning off completely
- Error message on display
Causes
- Open or short circuit in the HMI module power supply circuit
- Damage to the CAN bus wiring harness
- Oxidation of contacts in module connectors
- HMI module software failure
- Problems with the car's main control unit
How to Fix
- Check fuses associated with the HMI module
- Inspect the connectors and wiring of the module for damage
- Carry out CAN bus diagnostics
- Reboot the module (disconnect the battery for 10-15 minutes)
- Update HMI module software
- Repair only from an authorized dealer
Related codes
FAQ
What does the U18A3 code mean?
U18A3 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Human Machine Interface Control Module
What causes a U18A3 error code?
The most common causes of U18A3 include: Open or short circuit in the HMI module power supply circuit; Damage to the CAN bus wiring harness; Oxidation of contacts in module connectors; HMI module software failure.
How do I fix a U18A3 diagnostic trouble code?
To fix U18A3: Check fuses associated with the HMI module. Inspect the connectors and wiring of the module for damage. Carry out CAN bus diagnostics. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U18A3?
Limited driving only, diagnose soon
How much does it cost to fix U18A3?
The estimated repair cost for U18A3 is $56–278. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat