U1023
Lost Communications With Hybrid Control Module
U1023 is an OBD-II diagnostic trouble code meaning: Lost Communications With Hybrid Control Module. Common causes: open or short circuit in the can bus, problems with power supply of the hybrid module. Estimated repair cost: $167–889.
Symptoms
- Check Engine Light Is On
- The car goes into emergency mode
- Reduced power or hybrid system failure
- Problems with charging a high-voltage battery
- Inability to switch between driving modes
Causes
- Open or short circuit in the CAN bus
- Problems with power supply of the hybrid module
- Malfunction of the hybrid control module itself
- Corroded or damaged connectors
- Module grounding problems
How to Fix
- Check the integrity of the CAN bus and connections
- Check power supply and grounding of the hybrid module
- Inspect connectors for corrosion or damage
- Scan all modules for additional errors
- If necessary, replace the hybrid control module
Related codes
FAQ
What does the U1023 code mean?
U1023 is an OBD-II diagnostic trouble code that indicates: Lost Communications With Hybrid Control Module
What causes a U1023 error code?
The most common causes of U1023 include: Open or short circuit in the CAN bus; Problems with power supply of the hybrid module; Malfunction of the hybrid control module itself; Corroded or damaged connectors.
How do I fix a U1023 diagnostic trouble code?
To fix U1023: Check the integrity of the CAN bus and connections. Check power supply and grounding of the hybrid module. Inspect connectors for corrosion or damage. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U1023?
Do not drive — repair immediately
How much does it cost to fix U1023?
The estimated repair cost for U1023 is $167–889. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat