P0AA1-224

DESCRIPTION

The SMRs (System Main Relays), installed in the HV relay assembly, connect and disconnect the high-voltage power supply circuit in accordance with requests from the HV control ECU. To ensure a reliable operation, there are three SMRs in total (one for the negative side and two for the positive side).

To connect, SMR1 and SMR3 turn on initially. Then, SMR2 turns on and SMR1 turns off. This process protects the circuit from the high-voltage surge current by allowing the limit current to flow via the resistor. To disconnect, SMR2 and SMR3 turn off in that order. The HV control ECU checks that the relays have turned off properly.
The HV control ECU monitors operation of the SMRs (CON1, CON2, CON3) to check for malfunctions.

DTCNo.	INF Code	DTC Detection Condition	Trouble Area
P0AA1	224	Open or +B short in SMR1 (CON1) circuit	Wire harness or connector HV relay assembly HV control ECU
P0AA2	225	Short to GND in the SMR1 (CON1) circuit	Wire harness or connector HV relay assembly HV control ECU

WIRING DIAGRAM

INSPECTION PROCEDURE

CAUTION:

1. Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from reconnecting it while you are working on the high-voltage system.
   
2. After disconnecting the service plug grip, wait for at least 5 minutes before touching any of the high-voltage connectors or terminals.
   

HINT:

At least 5 minutes is required to discharge the high-voltage capacitor inside the w/ converter inverter assembly.

1. CHECK HARNESS AND CONNECTOR (HV CONTROL ECU - HV RELAY ASSEMBLY)

CAUTION:

Be sure to wear insulated gloves.

1. Turn the ignition switch off and remove the service plug grip. (Click here)

   NOTICE:

   Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.

2. Disconnect the H30 connector from the HV control ECU.

3. Disconnect the S48 connector from the HV relay assembly.

4. Measure the voltage according to the value(s) in the table below when the ignition switch is in the ON position.

   HINT:

   If the ignition switch is turned to the ON position with the service plug grip removed, the DTC (P0A0D-350) for the interlock switch system will be output.

   Standard Voltage:

   Tester Connection	Specified Condition
   CON1 (H30-3) - Body ground	Below 1 V

5. Turn the ignition switch off.

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

   Standard Resistance (Check for open):

   Tester Connection	Specified Condition
   CON1 (H30-3) - CON1 (S48-3)	Below 1 Ω

   Standard Resistance (Check for short):

   Tester Connection	Specified Condition
   CON1 (H30-3) or CON1 (S48-3) - Body ground	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2. INSPECT HV RELAY (SMR1)

CAUTION:

Be sure to wear insulated gloves.

1. Turn the ignition switch off and remove the service plug grip. (Click here)

   NOTICE:

   Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.

2. Remove the HV relay assembly from the vehicle. (Click here)

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

   Standard Resistance:

   Tester Connection	Specified Condition
   S47-1 - S44-1	Below 1 Ω (Apply auxiliary battery voltage between terminals (CON1 (S48-3) and GND (S48-4))

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

   Standard Resistance:

   Tester Connection	Specified Condition
   CON1 (S48-3) - GND (S48-4)	70 to 165 Ω at -30 to 70°C ( -22 to 176°F)

NG	REPLACE HV RELAY ASSEMBLY

OK
REPLACE HYBRID VEHICLE CONTROL ECU