P0ADF code meaning
Hybrid/EV Battery Negative Contactor Control Circuit Low
Powertrain system Generic code P0Axx codes Check engine light
What P0ADF means
P0ADF reports that the drive circuit of the negative main contactor is pulled too low, typically a short to ground in the coil line. GM documents the code in its 2016-19 hybrid tables: control voltage below 5.35 V while the contactor is commanded on, 13 of 16 samples at 12.5 ms (20 of 25 in one 2016 group), Type B with two trips, enabled above about 9 to 10 V on the 12 V system. CARB 1968.2 requires this kind of circuit monitoring for hybrid outputs. Counterparts are P0ADD (open), P0AE0 (high) and, on the positive side, P0ADB. As the contactor cannot close properly, the high-voltage system does not come up and the vehicle will not drive or charge.
P0ADF at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0ADF
- Vehicle will not enter ready mode or start
- Hybrid or EV warning light and check engine light
- Charging not possible
Common causes of P0ADF
- Most likelyCoil control wire shorted to ground
- PossibleNegative contactor coil internally shorted
- PossibleMoisture in the battery disconnect unit connector
- Less likelyDriver in the battery controller defective
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery neg contactorWiring harnessBms
What each part of P0ADF means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A | Area: hybrid propulsion. |
| DF | The exact fault in that area. |
What to do next
- Note P0ADF 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 P0ADF
What does P0ADF mean?
P0ADF means "Hybrid/EV Battery Negative Contactor Control Circuit Low". P0ADF reports that the drive circuit of the negative main contactor is pulled too low, typically a short to ground in the coil line. It is a generic code, so it means the same on every make.
Is it safe to drive with P0ADF?
Drive gently and only to a workshop. With P0ADF the car can go into limp mode (reduced power) to protect itself.
Will P0ADF fail an emissions test?
Yes, it can. P0ADF 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 P0ADF to fix?
Difficulty: workshop only. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0ADF clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.