OBD Guide
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U1890

Hybrid Control Module Lost Communication With HVAC Control Module

U1890 is an OBD-II diagnostic trouble code meaning: Hybrid Control Module Lost Communication With HVAC Control Module. Common causes: can bus break or damage, climate control module malfunction. Estimated repair cost: $56–278.

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

Symptoms

  • Climate control does not work
  • The hybrid system goes into emergency mode
  • Check Engine light comes on
  • Reduced performance of the hybrid system

Causes

  • CAN bus break or damage
  • Climate control module malfunction
  • Problems with module power supply
  • Contact corrosion
  • Software error

How to Fix

  1. Check the integrity of the CAN bus between modules
  2. Diagnose the climate control module
  3. Check power and ground of both modules
  4. Update module software
  5. Check connections in the high voltage system

Related codes

U1889U1891U0100

FAQ

What does the U1890 code mean?

U1890 is an OBD-II diagnostic trouble code that indicates: Hybrid Control Module Lost Communication With HVAC Control Module

What causes a U1890 error code?

The most common causes of U1890 include: CAN bus break or damage; Climate control module malfunction; Problems with module power supply; Contact corrosion.

How do I fix a U1890 diagnostic trouble code?

To fix U1890: Check the integrity of the CAN bus between modules. Diagnose the climate control module. Check power and ground of both modules. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1890?

Limited driving only, diagnose soon

How much does it cost to fix U1890?

The estimated repair cost for U1890 is $56–278. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat