OBD Guide

U0103

Lost Communication With Gear Shift Control Module A

Severity: HIGH

Symptoms

  • Check Engine light comes on
  • The car may not shift gears
  • It is possible to switch to emergency mode of operation of the gearbox
  • The instrument panel may display incorrect selector positions
  • Loss of power or acceleration problems

Causes

  • Open or short circuit in the CAN bus circuit
  • Shift Module Power Problems
  • Malfunction of the gear shift module itself
  • Poor contact in wiring connectors
  • Problems with the main ECU

How to Fix

  1. Check fuses associated with the shift module
  2. Inspect the wiring harness and connectors for damage.
  3. Check the module supply voltage
  4. Scan the CAN bus for communication errors
  5. If necessary, replace the gear shift module

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