Toyota Avalon (XX50): Hybrid/EV Battery Voltage Isolation Sensor Circuit Internal Electronic Failure (P0AA749). Hybrid/EV Battery Air Temperature Sensor "A" Circuit Short to Ground (P0AAC11,P0AAC15). Hybrid/EV Battery Curr

Hybrid/EV Battery Voltage Isolation Sensor Circuit Internal Electronic Failure (P0AA749)

DESCRIPTION

The hybrid vehicle control ECU monitors the insulation monitoring circuit located in the battery voltage sensor and detects malfunctions.

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

Click here

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
4. Turn the power switch off and wait for 2 minutes or more.
5. Turn the power switch on (IG) and turn the Techstream on.
6. With power switch on (IG) and wait for 70 seconds or more.
7. Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.
8. Check the DTC judgment result.

   HINT:

   • If the judgment result shows NORMAL, the system is normal.
   • If the judgment result shows ABNORMAL, the system has a malfunction.
   • If the judgment result shows INCOMPLETE or N/A, perform driving pattern again.

PROCEDURE

Click here

NEXT

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG) and wait for 70 seconds or more.

NOTICE:

Do not turn the power switch off until step 3 is complete.

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

(d) Check if DTCs are output.

B

REPLACE BATTERY VOLTAGE SENSOR

A

NOTICE:

Do not turn the power switch off while performing this inspection.

(a) With the vehicle and engine stopped, turn the power switch on (READY) with shift lever in P and wait for 70 seconds or more. (If the engine starts, wait until the engine stops.)

(b) While depressing the brake pedal without depressing the accelerator pedal, move the shift lever to D and wait for 1 minute. (Step A)

(c) Drive the vehicle 0.5 m (1.6 ft.) forward and perform step A.

(d) Drive the vehicle another 0.5 m (1.6 ft.) forward and perform step A. Repeat this procedure 5 times (minimum total driving distance: 2 m (6.6 ft.)).

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

(f) Check if DTCs are output.

A

REPLACE BATTERY VOLTAGE SENSOR

B

GO TO DTC CHART (P0AA649)

Hybrid/EV Battery Air Temperature Sensor "A" Circuit Short to Ground (P0AAC11,P0AAC15)

DESCRIPTION

The inlet air temperature sensor (battery) is mounted on the HV battery. The resistance of the sensor varies in accordance with changes in the intake air temperature. The characteristics of the inlet air temperature sensor are the same as those of the battery temperature sensors (Click here ). The battery voltage sensor uses signals from the inlet air temperature sensor to control the air volume of the battery cooling blower assembly.

HINT:

After checking for the above DTCs, check the hybrid system Data List item "Hybrid Battery Cooling Fan Intake Air Temperature 1" using the Techstream.

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

Click here

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
4. Turn the power switch off and wait for 2 minutes or more.
5. Turn the power switch on (IG) and turn the Techstream on.
6. With power switch on (IG) and wait for 5 seconds or more.
7. Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.
8. Check the DTC judgment result.

   HINT:

   • If the judgment result shows NORMAL, the system is normal.
   • If the judgment result shows ABNORMAL, the system has a malfunction.
   • If the judgment result shows INCOMPLETE or N/A, perform driving pattern again.

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0A9B2A.

Click here

CAUTION / NOTICE / HINT

CAUTION:

• Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.
  • Inspecting the high-voltage system
  • Disconnecting the low voltage connector of the inverter with converter assembly
  • Disconnecting the low voltage connector of the HV battery
• To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.
• After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
• After removing 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.

  Click here

  HINT:

  Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

  

  *a	Without waiting for 10 minutes

NOTICE:

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

Click here

PROCEDURE

(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 for DTCs.

(e) Turn the power switch off.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

A

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) Remove the No. 1 hybrid battery exhaust duct.

Click here

(c) Check the connections of the y6 battery voltage sensor connector. Click here OK: The connector is connected securely and there are no contact problems.

(d) Install the No. 1 hybrid battery exhaust duct.

NG

CONNECT SECURELY

OK

CAUTION:

Be sure to wear insulated gloves and protective goggles.

(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) Remove the upper HV battery cover sub-assembly.

Click here

(c) Visually check the installation condition of the inlet air temperature sensor. Result Proceed to The inlet air temperature sensor is installed in the correct location and its claws are engaged securely. A The claws of the inlet air temperature sensor are damaged. B The inlet air temperature sensor is not installed correctly, but its claws are not damaged. C

(d) Install the upper HV battery cover sub-assembly.

B

REPLACE HYBRID BATTERY THERMISTOR

C

INSTALL PARTS CORRECTLY

A

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) Remove the No. 1 hybrid battery exhaust duct.

Click here

(c) Disconnect the y6 battery voltage sensor connector.

NOTICE:

Before disconnecting the connector, check that it is not loose or disconnected.

(d) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition y6-1 (TC0) - y6-7 (GC0) Power switch off 0 to 10°C (32 to 50°F) 17.7 to 27.8 kΩ y6-1 (TC0) - y6-7 (GC0) Power switch off 10 to 20°C (50 to 68°F) 12.0 to 18.2 kΩ y6-1 (TC0) - y6-7 (GC0) Power switch off 20 to 30°C (68 to 86°F) 8.22 to 12.2 kΩ y6-1 (TC0) - y6-7 (GC0) Power switch off 30 to 40°C (86 to 104°F) 5.74 to 8.41 kΩ y6-1 (TC0) - y6-7 (GC0) Power switch off 40 to 50°C (104 to 122°F) 4.09 to 5.91 kΩ NOTICE: When taking a measurement with a tester, do not apply excessive force to the tester probe to avoid damaging the holder.

*a Rear view of wire harness connector (to Battery Voltage Sensor)

(e) Disconnect the K17 battery voltage sensor connector.

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

Standard Resistance:

(g) Reconnect the y6 and K17 battery voltage sensor connectors.

(h) Install the No. 1 hybrid battery exhaust duct.

OK

REPLACE BATTERY VOLTAGE SENSOR

NG

CAUTION:

Be sure to wear insulated gloves and protective goggles.

(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) Remove the upper HV battery cover sub-assembly.

Click here

(c) Check the wire harnesses and connectors of the battery temperature sensors and inlet air temperature sensor for abnormalities by sight and touch.

Specified Condition:

There are no open or short circuits in the wire harnesses and connectors. There are no short circuits to other wire harnesses.

(d) Install the upper HV battery cover sub-assembly.

OK

REPLACE HYBRID BATTERY THERMISTOR

NG

REPAIR HARNESS OR CONNECTOR (INLET AIR TEMPERATURE SENSOR)

Hybrid/EV Battery Current Sensor "A" Circuit Range/Performance (P0ABF00)

DESCRIPTION

A battery current sensor is installed to the positive (+) terminal side of the HV battery and detects current flowing from the HV battery. The battery current sensor outputs voltage, which changes between 0 and 5 V according to the detected amperage, to the IB terminal of the battery voltage sensor. The battery voltage sensor sends signals to the hybrid vehicle control ECU. The hybrid vehicle control ECU determines the charging and discharging amount of the HV battery based on the received signals and calculates the SOC of the HV battery through the accumulated amperage.

MONITOR DESCRIPTION

The hybrid vehicle control ECU detects malfunctions of the battery current sensor by monitoring motor and generator torque. If the hybrid vehicle control ECU detects a battery current sensor malfunction, the hybrid vehicle control ECU will illuminate the MIL and store a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

CONFIRMATION DRIVING PATTERN

HINT:

• After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

  Click here

• When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

  Click here

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
4. Turn the power switch off and wait for 2 minutes or more.
5. Turn the power switch on (IG) and turn the Techstream on.
6. Drive the vehicle for approximately 10 minutes according to the freeze frame data items "Vehicle Speed", "Accelerator Position", "Hybrid Battery Current", "Motor Torque" and "Generator Torque". [*1]

   HINT:

   [*1] : Normal judgment procedure.

   The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

7. Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.
8. Check the DTC judgment result.

   HINT:

   • If the judgment result shows NORMAL, the system is normal.
   • If the judgment result shows ABNORMAL, the system has a malfunction.
   • If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

PROCEDURE

(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 for DTCs.

(e) Turn the power switch off.

(f) Disconnect the Techstream from the DLC3.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

A

Click here

NG

REPLACE HYBRID BATTERY THERMISTOR

OK

Click here

NEXT

Click here

NEXT

(a) Drive the vehicle for approximately 10 minutes according to the freeze frame data items "Vehicle Speed", "Accelerator Position", "Hybrid Battery Current", "Motor Torque" and "Generated Torque".

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

NEXT

(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 for DTCs.

(e) Turn the power switch off.

A

END

B

REPLACE BATTERY VOLTAGE SENSOR