P27A2 code meaning
Electric/Auxiliary Transmission Fluid Pump B Control Circuit/Open
Powertrain system Generic code P27xx codes Check engine light
What P27A2 means
P27A2 flags a broken control circuit between the module and auxiliary pump B, the second electric fluid pump on gearboxes that carry two. While its output is energised, the controller compares the voltage on the line with the level an intact load would pull it to; a floating line reveals the interruption. No manufacturer documents P27A2 publicly. GM's 2025 TCM tables describe the identical test for pump A as P2796: more than 200 kΩ to ground in at least 20 of 25 samples taken every 100 ms, with 9 to 15 V supply, Type B. Audi ties its pump B codes to the gear oil pump V553 of the 0CJ, 0CK and 0CL twin-clutch units. P27A4 and P27A5 are the shorted variants. Typical faults are a cracked wire, a pushed-back pin or an open motor winding; stop-start is normally withdrawn.
P27A2 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P27A2
- Stop-start no longer active
- Transmission warning or MIL
- Harsh engagement when driving off after a restart
Common causes of P27A2
- Most likelyControl wire broken in the harness to pump B
- PossiblePump connector unplugged, pin pushed back or corroded
- PossibleOpen motor winding or internal connection in pump B
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Aux trans pump bPump relayWiring harness
What each part of P27A2 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 7 | Area: transmission. |
| A2 | The exact fault in that area. |
What to do next
- Note P27A2 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 P27A2
What does P27A2 mean?
P27A2 means "Electric/Auxiliary Transmission Fluid Pump B Control Circuit/Open". P27A2 flags a broken control circuit between the module and auxiliary pump B, the second electric fluid pump on gearboxes that carry two. It is a generic code, so it means the same on every make.
Is it safe to drive with P27A2?
Drive gently and only to a workshop. With P27A2 the car can go into limp mode (reduced power) to protect itself.
Will P27A2 fail an emissions test?
Yes, it can. P27A2 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 P27A2 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P27A2 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.