Gear Shift Control Module B Supply Voltage High
Supply voltage on the gear shift control module B is above the expected window.
Affected components
- Gear shift control module b
- Wiring harness
Common causes
- High likelihood: Alternator overvoltage
- Medium likelihood: Wire shorted to B+
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.