U1104
Lost Communication with Driving Support ECU
U1104 is an OBD-II diagnostic trouble code meaning: Lost Communication with Driving Support ECU. Common causes: problems with the can bus (break, short circuit), malfunction of the driving support systems control unit. Estimated repair cost: $22–167.
Symptoms
- The Check Engine Light or Other Warning Lights Come On
- Disabling driving support systems (adaptive cruise control, lane keeping assist)
- An error message appears on the dashboard display
- Reduced functionality of advanced security systems
- Possible problems with other systems using the CAN bus
Causes
- Problems with the CAN bus (break, short circuit)
- Malfunction of the driving support systems control unit
- Damaged wiring harness or poor connections
- Driving support unit power supply problems
- Software errors in the ECU
How to Fix
- Check the integrity of the CAN bus and connections
- Diagnose the driving support systems control unit
- Check the power and ground of the driving support unit
- Inspect the wiring harness for damage
- Update ECU software if necessary
Related codes
FAQ
What does the U1104 code mean?
U1104 is an OBD-II diagnostic trouble code that indicates: Lost Communication with Driving Support ECU
What causes a U1104 error code?
The most common causes of U1104 include: Problems with the CAN bus (break, short circuit); Malfunction of the driving support systems control unit; Damaged wiring harness or poor connections; Driving support unit power supply problems.
How do I fix a U1104 diagnostic trouble code?
To fix U1104: Check the integrity of the CAN bus and connections. Diagnose the driving support systems control unit. Check the power and ground of the driving support unit. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U1104?
Limited driving only, diagnose soon
How much does it cost to fix U1104?
The estimated repair cost for U1104 is $22–167. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat