Gear Shift Control Module A Communication Circuit High
The gear shift control module A communication circuit reports a communication circuit high condition. Shift command exchange is impaired.
Affected components
- Gear shift control module a
- Wiring harness
Common causes
- High likelihood: Bus wire shorted to B+
- Medium likelihood: Module output high
- Low likelihood: Gateway module routing CAN messages incorrectly
Possible symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Diagnostic notes
- The malfunction indicator lamp may illuminate
- Reduced-power or limp mode may occur
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.