P07A9 code meaning
Transmission Friction Element D Stuck On
Powertrain system Generic code P07xx codes Check engine light
What P07A9 means
Each friction element (clutch or brake) has three functional codes: slip while commanded locked (P079A ff), performance/stuck off – it does not apply or applies too weakly – and stuck on – it does not release. GM's hybrid transmissions use only the stuck-on codes: when a clutch should release, the module expects slip to build and flags it if slip stays near zero – the Two-Mode SUVs (2008–13) in two cases: in mode 1 at very low slip with strong deceleration of slip and over 700 Nm for 3.2 s, in mode 2 at 80 rpm or less with over 180 Nm for 4.5 s, after two trips. The Cadillac CT6 plug-in compares with the release profile, 1 s, after one trip. Volt and Malibu do not use clutch 4.
P07A9 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 12 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P07A9
- Check engine light or 'service hybrid system' message
- Jolt or tie-up on mode or gear changes
- Engine stalls or drags when stopping
- Limp mode with reduced power
Common causes of P07A9
- Most likelyClutch D stuck, welded or piston hanging
- PossibleValve or spool sticking in the applied position
- PossibleContaminated fluid (debris)
- Less likelyModule software
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Transmission clutchesTransmission valve bodyHybrid control module
What each part of P07A9 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7 | Area: transmission. |
| A9 | The exact fault in that area. |
What to do next
- Note P07A9 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 P07A9
What does P07A9 mean?
P07A9 means "Transmission Friction Element D Stuck On". Each friction element (clutch or brake) has three functional codes: slip while commanded locked (P079A ff), performance/stuck off – it does not apply or applies too weakly – and stuck on – it does not release. It is a generic code, so it means the same on every make.
Is it safe to drive with P07A9?
Drive gently and only to a workshop. With P07A9 the car can go into limp mode (reduced power) to protect itself.
Will P07A9 fail an emissions test?
Yes, it can. P07A9 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 P07A9 to fix?
Difficulty: hard. A typical repair takes 1 to 12 hours of work. This is a job for a workshop.
Will P07A9 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.