Up and Down Shift Switch Circuit
The TCM detects a fault in the combined up/down shift switch circuit, where both switch states are simultaneously active or both inactive when activity is expected.
Affected components
- Shift switch assembly
- Wiring harness
Common causes
- High likelihood: Switch internal short
- Medium likelihood: Wiring shorted between channels
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
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.