P0AB9Hybrid/EV System Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Despite the broad title, GM uses P0AB9 for one concrete check: a failed engine auto-start or auto-stop in its hybrids, including an engine stall during that process. In the 2016 and 2019 hybrid tables the hybrid controller sets the code when the engine still reports no torque about 15 seconds into an auto-start although more than 20 Nm is commanded, provided fuel level is sufficient and no cam or crank fault is present. The 2011 and 2013 tables describe the same idea with a stall during start/stop. GM rates it Type A, so the MIL comes on after one trip. Other faults that prevent starting, such as P0A0F, point at more specific causes; P0AB9 itself is the symptom.
- What you may notice
- Check engine light on
- Engine hesitates, fails or stalls when restarting at a stop
- Auto-stop disabled for the rest of the trip
- Likely causes
- LikelyFuel delivery problem (weak pump, nearly empty tank, clogged filter)
- PossibleIgnition or injector fault that prevents the engine from firing
- PossibleStarter-generator or motor unable to spin the engine to start speed
- RareController software needing an update
- 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.