DTC P0AA1 (46)
DTC P0AA1 (46): HV Main Contactor Circuit Stuck Closed
General Description
The electric powertrain turns off the contactor when the vehicle is turned to the OFF (LOCK) mode, when the plug-in charge is stopped or the system is shut down by fail safe action. When either the main contactor-positive or the main contactor-negative is turned off, the electric charge of the power drive unit (PDU) capacitor in the inverter is discharged by the DC-DC converter or the precharge resistor, and the inverter voltage drops. In case of a contactor on malfunction, the electric charge of the PDU capacitor in the inverter will not be discharged, and the inverter voltage does not drop. The battery condition monitor module A monitors the inverter voltage when the vehicle is running and battery charger voltage when charging. The battery condition monitor module A detects a malfunction and stores a DTC when the difference between the inverter voltage and the inverter voltage before turning OFF the contactor is within the prescribed value continuously for the prescribed time.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | After the vehicle condition is turned to the OFF (LOCK) mode or after stopping the plug-in charge |
| Sequence | None |
| Duration | - |
| DTC Type | One drive cycle, MIL on, POWER SYSTEM indicator on, 12 volt battery charging system indicator on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Battery condition monitor module A power-supply voltage | 10.2 V | - |
| Inverter voltage difference | - | 22.0 V |
| Inverter voltage | 118.0 V | 368.0 V |
| Battery pack voltage difference | - | 2.9 V |
| Vehicle condition | Vehicle OFF (LOCK) mode, or Plug-in charge off, or Plug-in quick charge off | |
Malfunction Threshold
The voltage difference between the inverter voltages before and after turning the contactor OFF is 40 V or less for at least 120 seconds.
Possible Cause
- Main contactor A-positive CNT1(A) line short
- Main contactor B-positive CNT1(B) line short
- Main contactor A-positive stuck on
- Main contactor B-positive stuck on
- Precharge contactor A-positive stuck on
- Precharge contactor B-positive stuck on
- Battery condition monitor module internal circuit failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL and the POWER SYSTEM indicator, and the 12 volt battery charging system indicator comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the battery condition monitor module A memory.
Conditions for clearing the DTC
The MIL, the POWER SYSTEM indicator and the 12 volt battery charging system indicator are cleared if the malfunction does not return on the next trip in which the diagnostic runs. The MIL, the POWER SYSTEM indicator and the 12 volt battery charging system indicator, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.