OBD Guide

U1838

Lost Communication With Battery Charger Control Module On High Voltage Energy Management CAN Bus

U1838 is an OBD-II diagnostic trouble code meaning: Lost Communication With Battery Charger Control Module On High Voltage Energy Management CAN Bus. Common causes: open or short circuit in can circuit, charging control module malfunction. Estimated repair cost: $56–278.

Severity
🔴 High
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–278 (est.)

Symptoms

  • Check Engine light comes on
  • Problems with charging a high-voltage battery
  • Reduced vehicle power
  • Errors in the operation of the hybrid system
  • Inability to charge the battery

Causes

  • Open or short circuit in CAN circuit
  • Charging control module malfunction
  • Module power problems
  • Corrosion of connectors
  • Software error in the module

How to Fix

  1. Check the integrity of the CAN bus wiring harness
  2. Check the power and ground of the charging control module
  3. Inspect connectors for corrosion
  4. Scan other modules for errors
  5. Update module software
  6. Repair only from an authorized dealer

Related codes

FAQ

What does the U1838 code mean?

U1838 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Battery Charger Control Module On High Voltage Energy Management CAN Bus

What causes a U1838 error code?

The most common causes of U1838 include: Open or short circuit in CAN circuit; Charging control module malfunction; Module power problems; Corrosion of connectors.

How do I fix a U1838 diagnostic trouble code?

To fix U1838: Check the integrity of the CAN bus wiring harness. Check the power and ground of the charging control module. Inspect connectors for corrosion. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1838?

Yes, but get it checked soon

How much does it cost to fix U1838?

The estimated repair cost for U1838 is $56–278. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat