U1878
Drive Motor B Control Module Lost Communication With Battery Energy Control Module
U1878 is an OBD-II diagnostic trouble code meaning: Drive Motor B Control Module Lost Communication With Battery Energy Control Module. Common causes: can bus break or damage, problems with module power supply. Estimated repair cost: $56–278.
Symptoms
- Check Engine light comes on
- Reduced motor power
- Incorrect operation of the hybrid system
- Errors in the operation of the energy recovery system
- The vehicle goes into emergency mode
Causes
- CAN bus break or damage
- Problems with module power supply
- Motor control module B malfunction
- Battery Energy Management Module malfunction
- Corrosion or poor contact in connectors
How to Fix
- Check the integrity of the CAN bus between modules
- Check power and ground on both modules
- Inspect connectors for corrosion or damage
- Read error codes from both modules for additional diagnostics
- If necessary, replace the faulty module
Related codes
FAQ
What does the U1878 code mean?
U1878 is an OBD-II diagnostic trouble code that indicates: Drive Motor B Control Module Lost Communication With Battery Energy Control Module
What causes a U1878 error code?
The most common causes of U1878 include: CAN bus break or damage; Problems with module power supply; Motor control module B malfunction; Battery Energy Management Module malfunction.
How do I fix a U1878 diagnostic trouble code?
To fix U1878: Check the integrity of the CAN bus between modules. Check power and ground on both modules. Inspect connectors for corrosion or damage. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U1878?
Limited driving only, diagnose soon
How much does it cost to fix U1878?
The estimated repair cost for U1878 is $56–278. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat