P05D3Driver Mode Select Switch A Range/Performance
- 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. P05D3 means the voltage lies between the low and high limits but in a dead band between two valid positions, so no position is clear – at GM for example 1.327–1.427 V or 2.967–3.348 V (petrol) and 0.528–0.628 V (diesel). Typical are contact resistance shifting all steps or a rotary switch resting between two detents.
- What you may notice
- Selected mode not taken over or jumping
- Check engine light (GM after two trips)
- Mode display missing
- Likely causes
- LikelyCorroded connector or increased contact resistance
- PossibleSwitch worn or detent unclear (knob between two positions)
- PossibleMoisture in the switch
- RareGround offset at the switch
- 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.