Toyota Avalon Service & Repair Manual: Hybrid/EV Battery Voltage Isolation Sensor Circuit Internal Electronic Failure (P0AA749)

Toyota Avalon Service & Repair Manual / Engine / Hybrid / Battery Control / Hybrid Control System / 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.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0AA749

Hybrid/EV Battery Voltage Isolation Sensor Circuit Internal Electronic Failure

Malfunction in the insulation monitoring circuit in the battery voltage sensor

(1 trip detection logic)

Battery voltage sensor

Does not come on

Master Warning Light:

Comes on

Related Data List

DTC No.

Data List

P0AA749

Short Wave Highest Value Level

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

1.

CLEAR DTC

Click here

NEXT

2.

SIMULATION TEST

(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.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

P0AA749 is not output.

A

P0AA749 is output.

B

B

REPLACE BATTERY VOLTAGE SENSOR

A

3.

SIMULATION TEST

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.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

P0AA649 is not output.

A

P0AA649 is output.

B

A

REPLACE BATTERY VOLTAGE SENSOR

B

GO TO DTC CHART (P0AA649)

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