P0AD9Hybrid/EV Battery Positive Contactor Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The positive main contactor connects the traction battery to the high-voltage bus; its coil is driven by the battery or hybrid controller. P0AD9 covers an open in this coil circuit. GM documents it in detail: in hybrid tables from model year 2011 the HPC2 sets it on open load during the commanded state, Type B. 2016-19 tables use a control voltage between 1.15 and 2.81 V with the contactor commanded off, 40 of 50 samples at 12.5 ms; 2019 versions also check coil current below 194 mA when on. CARB requires circuit monitoring of hybrid outputs. Low and high faults are P0ADB and P0ADC; a contactor stuck open is P0AA2. The car usually cannot go ready.
- What you may notice
- Vehicle will not enter ready mode or start
- Hybrid or EV warning light and check engine light
- Charging not possible
- Likely causes
- LikelyOpen in the contactor coil or its pigtail inside the battery disconnect unit
- PossibleLoose or corroded low-voltage connector at the battery disconnect unit
- PossibleBroken control wire in the battery harness
- RareHigh-side driver in the battery controller defective
- 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: €100 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.