What Does U0103 Mean?
The vehicle's control module network has lost communication with the gear shift module. This module manages electronic shifter position and transmission range selection communication.
Safety Warning
Vehicle may not shift properly or start, potentially causing it to be stuck in park or neutral. Unsafe to drive if transmission function is compromised.
Common Causes
35%
Faulty or corroded wiring/connectors between gear shift module and CAN bus network
30%
Failed gear shift control module
20%
CAN bus network fault affecting multiple modules
10%
Power supply issue to gear shift module
5%
Software/firmware corruption in gear shift module
Diagnostic Steps
1
Step 1: Verify power and ground circuits to gear shift module using multimeter
2
Step 2: Inspect connectors and wiring at gear shift module for corrosion, damage, or loose pins
3
Step 3: Check CAN bus voltage between CAN High and CAN Low at gear shift module connector (should be ~2.5V with key on)
4
Step 4: Scan for additional U-codes to determine if communication loss is isolated or network-wide
5
Step 5: Test gear shift module functionality in isolation or substitute known-good module if available
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
The vehicle's control module network has lost communication with the gear shift module. This module manages electronic shifter position and transmission range selection communication.
The most common cause of U0103 (Lost Communication With Gear Shift Module) is: Faulty or corroded wiring/connectors between gear shift module and CAN bus network
Typical repair costs for U0103 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may not shift properly or start, potentially causing it to be stuck in park or neutral. Unsafe to drive if transmission function is compromised.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0103 to identify the root cause.
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Quick Info
Category
Network
System
Transmission Control / Network Communication
Difficulty
Type
Generic (SAE)
Recommended Tools
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