P09A2 code meaning
Gate Select Position Circuit B
Powertrain system Generic code P09xx codes Check engine light
What P09A2 means
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.
P09A2 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P09A2
- Check engine or transmission warning light on
- Gearbox shifts slowly or locks out certain gears
- Gearbox stays in one gear or neutral
Common causes of P09A2
- Most 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
- Less likelyFaulty input stage for circuit B in the transmission control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Gate select position sensor bWiring harnessTCM
What each part of P09A2 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9 | Area: transmission. |
| A2 | The exact fault in that area. |
What to do next
- Note P09A2 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P09A2
What does P09A2 mean?
P09A2 means "Gate Select Position Circuit B". General electrical fault on the second gate select position signal (circuit B) of an automated manual gearbox. It is a generic code, so it means the same on every make.
Is it safe to drive with P09A2?
Drive gently and only to a workshop. With P09A2 the car can go into limp mode (reduced power) to protect itself.
Will P09A2 fail an emissions test?
Yes, it can. P09A2 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P09A2 to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P09A2 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.