OBD Codes

U0201

Lost Communication with Door Control Module "C"

Moderateelectrical

Overview

The U0201 code indicates a lost communication with door control module "c" condition on the vehicle's communication network. This diagnostic trouble code means that one or more control modules are unable to communicate over the CAN bus or other vehicle networks. Communication failures can cause multiple systems to malfunction simultaneously and should be diagnosed promptly to restore proper vehicle operation.

Symptoms

  • Electrical accessories malfunctioning
  • Check Engine Light (MIL) illuminated
  • Intermittent electrical failures
  • Erratic gauge readings

Common Causes

  • Failed relay or fuse
  • Low battery voltage or failing battery
  • Faulty alternator/generator
  • Short or open circuit in wiring

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
  2. 2Check battery voltage and charging system output with a multimeter
  3. 3Inspect wiring and connectors related to the trouble code
  4. 4Test circuit voltage, ground, and resistance with a multimeter
  5. 5Check related fuses and relays

Estimated Repair Cost

$75$400

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

BMW 3 SeriesRam 1500Hyundai SonataHonda Ridgeline

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Frequently Asked Questions

Electrical codes can be challenging because they often involve intermittent issues. A thorough inspection of wiring, connectors, and grounds with a multimeter is essential for accurate diagnosis.