P0A94-547

DESCRIPTION

Refer to the description of the boost converter. (Click here)
If the boost converter detects a circuit malfunction or overvoltage, it transmits this information to the OVL terminal of the MG ECU via the boost converter overvoltage signal line.

DTC No.	INF Code	DTC Detection Condition	Trouble Area
P0A94	547	Boost converter overvoltage signal detection (overvoltage by MG ECU malfunction)	HV relay assembly w/ converter inverter assembly (MG ECU)
↑	548	Boost converter overvoltage signal detection (overvoltage by inverter malfunction)	HV relay assembly w/ converter inverter assembly (MG ECU)

MONITOR DESCRIPTION

If the boost converter detects overvoltage, it transmits a boost converter overvoltage signal to the MG ECU. Upon receiving this signal, the HV control ECU illuminates the MIL and sets a DTC.

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. READ OUTPUT DTC (HV)

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch to the ON position.

3. Select the following menu items: Powertrain / Hybrid Control / DTC.

4. Read output DTCs. (Click here)
   

   Result:

   The DTCs shown in the table below are output:

   DTC No.	INF Code	Detection Item
   P0A78	266, 280	Motor inverter function malfunction
   P0A94	558, 559, 588, 589	Boost converter circuit malfunction
   P0A95	123	High voltage fuse blown out
   P0AA1	226	SMR+ stuck closed
   P0AA2	227	SMR+ stuck open
   P0AA4	228	SMR- stuck closed
   P0AA5	229	SMR- stuck open
   P3004	803	High-current wiring malfunction

   HINT:

   1. Turning the ignition switch to the ON position with the service plug grip and inverter cover removed causes interlock switch system DTC P0AD-350 output.
      
   2. P0A94-547 and P0A94-548 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.
      

YES	GO TO DTC CHART

NO

2. CHECK CONNECTION CONDITION OF MG ECU CONNECTOR (LOOSENESS AND POOR CONTACT)

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 inverter cover. (Click here)

   NOTICE:

   1. Wrap the interlock round terminal for the inverter cover with vinyl tape to prevent it from shorting to ground.
      
   2. Prevent water in the reservoir tank from entering the inverter.
      
   3. Removing the inverter cover causes the MG ECU board to be exposed. Therefore, temporarily install the inverter cover for each area to be inspected.
      

3. Check the connections of all MG ECU connectors.

   OK:

   Connectors are connected securely and there is no poor connection.
   

NG	CONNECT SECURELY

OK

3. INSPECT HV RELAY ASSEMBLY (SMR2)

CAUTION:

Be sure to wear insulated gloves.

1. Check that the service plug grip is removed.

2. Remove the HV relay assembly from the vehicle.

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 CON2 (S48-1) and GND (S48-4))

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

   Standard Resistance:

   Tester Connection	Specified Condition
   CON2 (S48-1) - GND (S48-4)	20 to 60 Ω at -35 to 80°C ( -31 to 176°F)

NG	REPLACE HV RELAY ASSEMBLY

OK

4. INSPECT HV RELAY ASSEMBLY (SMR3)

CAUTION:

Be sure to wear insulated gloves.

1. Check that the service plug grip is removed.

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

   Standard Resistance:

   Tester Connection	Specified Condition
   S49-1 - S45-1	Below 1 Ω (Apply auxiliary battery voltage between terminals CON3 (S48-2) and GND (S48-4))

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

   Standard Resistance:

   Tester Connection	Specified Condition
   CON3 (S48-2) - GND (S48-4)	20 to 60 Ω at -35 to 80°C ( -31 to 176°F)

NG	REPLACE HV RELAY ASSEMBLY

OK
REPLACE W/ CONVERTER INVERTER ASSEMBLY