OBD Guide
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U1803

Lost Communication With Hybrid/EV Powertrain Control Module 2

U1803 is an OBD-II diagnostic trouble code meaning: Lost Communication With Hybrid/EV Powertrain Control Module 2. Common causes: broken or damaged wires in the communication circuit, malfunction of hybrid/ev powertrain control module 2. Estimated repair cost: $56–278.

Severity
🔴 High
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–278 (est.)

Symptoms

  • Check Engine light comes on
  • Reduced power or unstable engine operation
  • Problems with switching operating modes of the hybrid system
  • Disabling regenerative braking systems
  • Error messages on the dashboard

Causes

  • Broken or damaged wires in the communication circuit
  • Malfunction of hybrid/EV powertrain control module 2
  • Connector problems or contact corrosion
  • Module software failures
  • Problems with module power supply (blown fuse)

How to Fix

  1. Check the integrity of the wiring and connectors in the communication circuit
  2. Scan all modules for additional errors
  3. Check the fuses associated with the module power supply
  4. Update control module software (if available)
  5. If necessary, replace the faulty control module
  6. Repair only from an authorized dealer

Related codes

U1800U1801U1802

FAQ

What does the U1803 code mean?

U1803 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Hybrid/EV Powertrain Control Module 2

What causes a U1803 error code?

The most common causes of U1803 include: Broken or damaged wires in the communication circuit; Malfunction of hybrid/EV powertrain control module 2; Connector problems or contact corrosion; Module software failures.

How do I fix a U1803 diagnostic trouble code?

To fix U1803: Check the integrity of the wiring and connectors in the communication circuit. Scan all modules for additional errors. Check the fuses associated with the module power supply. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1803?

Limited driving only, diagnose soon

How much does it cost to fix U1803?

The estimated repair cost for U1803 is $56–278. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat