DTC P0AA3 (128)
DTC P0AA3 (128): HV Sub Contactor Circuit
General Description
In the electric powertrain system, the main contactor-positive is turned OFF and the main contactor-positive weld detection is performed when the vehicle condition is turned to the OFF (LOCK) mode or when the plug-in charge is stopped, or the system is stopped by fail safe action. Then, the precharge contactor is turned ON, the main contactor-negative is turned OFF after performing precharge resister disconnection detection and the main contactor-negative weld detection is performed. When the main contactor-negative is turned OFF, the electric charge stored in the power drive unit (PDU) capacitor of the inverter is discharged by the DC-DC converter and the discharge resistor to cause the inverter voltage to decrease. In case of a main contactor-negative stuck-ON failure, the Inverter voltage does not decrease since the above-mentioned discharge does not occur. When vehicle condition is turned to the OFF (LOCK) mode, the voltage value is monitored by the inverter voltage sensor, and when charging, the voltage value is monitored by the battery charger voltage sensor and when the difference in the voltage before and after turning OFF the main contactor-negative to be within the specified value for a set time, the battery condition monitor module A detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | After the vehicle condition is turned to the OFF (LOCK) mode or after stop the plug-in charge |
| Sequence | None |
| Duration | - |
| DTC Type | One drive cycle, MIL off, POWER SYSTEM indicator on, 12 volt battery charging system indicator off |
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 main contactor-negative OFF is 15.3 V or less for at least 70 seconds.
Possible Cause
- Main contactor A-negative CNT2(A) line short to ground
- Main contactor B-negative CNT2(B) line short to ground
- Main contactor A-negative stuck on
- Main contactor B-negative stuck on
- Battery condition monitor module A internal circuit failure
Confirmation Procedure
Operating Condition
- Turn the vehicle to the ON mode.
- Turn the vehicle to the OFF (LOCK) mode, and wait at least 220 seconds.
With the HDS
None.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the POWER 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 POWER SYSTEM indicator is cleared if the malfunction does not return in next trip in which the diagnostic runs. The POWER SYSTEM indicator, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.