Transmission Mode Switch A Circuit High
Same as P071A with the signal shorted to supply. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Affected components
- Transmission mode switch a
Common causes
- High likelihood: Signal shorted to supply
- Low likelihood: Connector pins corroded - high contact resistance
- Low likelihood: Supply wire pinched against B+ source
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
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.