P09A2Gate Select Position Circuit B
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- General electrical fault on the second gate select position signal (circuit B) of an automated manual gearbox. The published designs from Isuzu (one select potentiometer) and Aisin AI (one select stroke sensor) show only a single sensor, so it is not documented whether B is a redundant second track of that sensor or a separate sensor. No manufacturer documents this code publicly. CARB requires circuit checks on such inputs. P09A4 and P09A5 are the more specific low and high faults of circuit B, P09A3 its plausibility fault; unlike circuit A (P0908) there is no intermittent variant. P0904 and P09A6 cover circuits A and C. Expect shifting to be restricted.
- What you may notice
- Check engine or transmission warning light on
- Gearbox shifts slowly or locks out certain gears
- Gearbox stays in one gear or neutral
- Likely causes
- LikelyLoose, corroded or wet connector at the select sensor or actuator unit
- PossibleChafed or broken signal wire of circuit B near the gearbox
- PossibleFaulty select sensor, often integrated in the shift and select actuator
- RareFaulty input stage for circuit B in the transmission control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.