OBD Guide

U1849

Drive Motor Control Module 1 Lost Communication With Transmission Control Module

U1849 is an OBD-II diagnostic trouble code meaning: Drive Motor Control Module 1 Lost Communication With Transmission Control Module. Common causes: open or short circuit in the can bus, engine control module (ecm) malfunction. Estimated repair cost: $17–89.

Severity
🔴 High
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Check Engine Light Is On
  • The car goes into emergency mode
  • Gear shifting problems
  • Reduced engine power
  • Unstable operation at idle

Causes

  • Open or short circuit in the CAN bus
  • Engine control module (ECM) malfunction
  • Problems with the automatic transmission control module (TCM)
  • Poor contact in connectors
  • Damage to the wiring harness between the ECM and TCM

How to Fix

  1. Check the integrity of the CAN bus with a multimeter
  2. Inspect ECM/TCM connectors and contacts for oxidation
  3. Scan both modules for errors
  4. Check power and ground of modules
  5. If necessary, replace damaged wires or connectors

Related codes

FAQ

What does the U1849 code mean?

U1849 is an OBD-II diagnostic trouble code that indicates: Drive Motor Control Module 1 Lost Communication With Transmission Control Module

What causes a U1849 error code?

The most common causes of U1849 include: Open or short circuit in the CAN bus; Engine control module (ECM) malfunction; Problems with the automatic transmission control module (TCM); Poor contact in connectors.

How do I fix a U1849 diagnostic trouble code?

To fix U1849: Check the integrity of the CAN bus with a multimeter. Inspect ECM/TCM connectors and contacts for oxidation. Scan both modules for errors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1849?

Yes, but get it checked soon

How much does it cost to fix U1849?

The estimated repair cost for U1849 is $17–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat