P0AA4

HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM: P0AA4-232: Hybrid Battery Negative Contactor Circuit Stuck Closed
P0AA4-232 - Hybrid Battery Negative Contactor Circuit Stuck Closed

DESCRIPTION

The SMRs (System Main Relay) 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 hybrid battery junction block assembly in the battery carrier under the HV battery. SMRP and the system main resistor are located in the hybrid vehicle converter (DC/DC converter) assembly in the battery carrier.

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 the 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:





P0AE6-225 is output first because the time required for diagnosis is the shortest.






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) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check if DTCs are output.

Result:









HINT
- *1: If any INF codes are output for this DTC, refer to the corresponding diagnostic procedure.
- P0AA4-232 may be output due to a malfunction which causes the DTCs in the table above to be output. In this case, first troubleshoot the output DTCs in the table above. Then, perform a reproduction test to check that no DTCs are output.
(e) Turn the power switch off.

B -- GO TO DTC CHART Hybrid Control System
A -- Continue to next step.

2. CHECK DTC OUTPUT (HV)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check if DTCs are output.

Result:





HINT
P0AA4-232 may be output due to a malfunction which causes the DTC in the table above to be output. In this case, first troubleshoot the output DTC in the table above. Then, perform a reproduction test to check that no DTCs are output.

(e) Turn the power switch off.

B -- GO TO DTC CHART
A -- Continue to next step.

3. CHECK FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Read the freeze frame data of DTC P0AA4-232. Result

Result:





(e) Turn the power switch off.

A -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Components
B -- Continue to next step.

4. CHECK HYBRID BATTERY JUNCTION BLOCK ASSEMBLY

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

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.

(b) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





HINT
- If a system main relay is stuck closed, inspect the hybrid battery junction block assembly without removing it from the vehicle, in order to keep the relay closed.
- In the previous step, if the result of reading the freeze frame data was B, this indicates that the hybrid battery junction block assembly must be replaced. The purpose of measuring the resistance in this step is to determine whether the malfunction is either a present or past malfunction.
NG -- REPLACE HYBRID BATTERY JUNCTION BLOCK ASSEMBLY Components

OK -- REPLACE HYBRID BATTERY JUNCTION BLOCK ASSEMBLY Components