P05D6Driver Mode Select Switch B Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The driver mode select switch (tour, sport, eco, snow, off-road, towing) changes engine and transmission maps such as shift points, pedal map and cylinder deactivation, so CARB requires it to be monitored as an input. GM reads switch A as an eight-position resistor ladder in the body module and sets P05D1–P05D3 in its 2025 tables when a condition is present for 4 s within 5 s, type B with warning lamp after two trips. A fault blocks mode selection; the vehicle stays in its basic mode. No manufacturer document available to us uses codes for switch B (a second mode switch or second signal line); its monitoring is assumed to match switch A. P05D6 means its signal is above the valid range – with a pull-up usually an open circuit, otherwise a short to positive, like P05D2 for switch A.
- What you may notice
- Mode selection via switch B inoperative
- Check engine light possible
- Vehicle stays in its basic mode
- Likely causes
- LikelyConnector off or wire open
- PossibleSwitch B faulty
- RareShort to positive
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.