P0A79Drive Motor B Inverter Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0A79 is the drive motor B counterpart of P0A78: the inverter stage for motor B has detected a power-switch fault. In GM hybrid OBD tables the IGBT module reports a desaturation status on a high or low side switch of any phase; persisting for about 2 ms it sets P0A79 as Type A with MIL on the first trip. Stellantis documents P0A79 several times: on the 2021 Jeep Wrangler 4xe together with P0A78 and an engine-only limp mode, fixed by a new power inverter module; on the 2017 Pacifica Hybrid with improved hybrid control software, and with a loose high-voltage cable at the inverter terminal that also caused loss of propulsion. P0A78 is motor A, P0A7A the generator inverter, P0A3D overheating of inverter B. The driver loses electric drive.
- What you may notice
- MIL and hybrid system warning
- No electric drive, engine-only operation
- Loss of propulsion in severe cases
- Likely causes
- LikelyIGBT desaturation or short in the motor B power stage
- LikelyPower inverter module defective
- PossibleLoose high-voltage cable at the inverter terminal (Pacifica Hybrid)
- PossibleHybrid control software requiring update
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €200 – €6,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.