P0AA4

L110F HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0AA4-232: Hybrid Battery Negative Contactor Circuit Stuck Closed

DTC P0AA4-232 - Hybrid Battery Negative Contactor Circuit Stuck Closed

DESCRIPTION

The SMRs (System Main Relays) are the relays that connect or disconnect the high voltage power system in accordance with commands from the hybrid vehicle control ECU.
The SMR system is composed of three SMRs and one system main resistor. SMRB and SMRG are located on the HV battery junction block in the HV battery pack. SMRP and the system main resistor are located in the hybrid vehicle converter (DC/DC converter) assembly in the HV battery pack.
To connect to the high voltage power system, the vehicle will first turn on SMRP and SMRB to charge the vehicle through the system main resistor. Then, SMRP will be turned off after SMRG is turned on. To shut off the high voltage power system, SMRB and SMRG are turned off.
When there is an open in the AMD line or IGCT line, the following DTCs are output:






WIRING DIAGRAM








INSPECTION PROCEDURE
CAUTION:
- Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
- After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
HINT:
- Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.
- If P0AA4-232 is stored, the hybrid system cannot be turned on.

PROCEDURE

1. CHECK DTC OUTPUT (HV)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:










B -- GO TO DTC CHART
A -- Continue to next step.
2. CHECK FREEZE FRAME DATA
(a) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(b) Read the freeze frame data of DTC P0AA4-232.
Result:






A -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
B -- Continue to next step.
3. CHECK HV BATTERY JUNCTION BLOCK
CAUTION:
Be sure to wear insulated gloves.
(a) Turn the power switch off.




(b) Remove the service plug grip L110F Hybrid Vehicle Control System.
NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.
(c) Disconnect the high voltage connector of the HV battery junction block.
HINT: For the removal and installation procedures related to inspection of the HV battery junction block, Components.
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:





HINT:
- If a system main relay is stuck closed, impacts or vibrations during the inspection may cause it to open.
- If the result of reading the freeze frame data is B, the HV battery junction block must be replaced. Measuring resistance can determine that this is either a present or past malfunction.

NG -- REPLACE HV BATTERY JUNCTION BLOCK
OK -- REPLACE HV BATTERY JUNCTION BLOCK