Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: IG Signal Circuit

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Vehicle Interior / Lighting (int) / Lighting System(for Gasoline Model) / IG Signal Circuit

DESCRIPTION

This circuit detects the engine switch on (IG) or off condition, and sends it to the main body ECU (multiplex network body ECU).

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • First, check for smart key system (for Start Function) DTCs, and after confirming that there is no malfunction, proceed with troubleshooting.

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  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration.

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PROCEDURE

1.

READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Main Body > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

IG SW

Engine switch on (IG) signal

OFF or ON

OFF: Engine switch off

ON: Engine switch on (IG)

"OFF" is also displayed for this item when the engine switch is on (ACC).
Body Electrical > Main Body > Data List

Tester Display

IG SW

OK:

Normal conditions listed above are displayed.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

(a) Disconnect the 4K and 4D instrument panel junction block assembly connectors.

(b) Disconnect the G32 main body ECU (multiplex network body ECU) connector.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

4K-1 - Body ground

Always

11 to 14 V

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4D-3 - Body ground

Always

Below 1 Ω

G32-19 (GND2) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

*a

Component without harness connected (Instrument Panel Junction Block Assembly)

-

-

(a) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4K-1 - MB-32 (IG)

Battery not connected to 4A-17 and 4D-3

10 kΩ or higher

4K-1 - MB-32 (IG)

Battery positive (+) → 4A-17

Battery negative (-) → 4D-3

Below 1 Ω
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    How To Proceed With Troubleshooting

    Interior Light Auto Cut Circuit

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    DESCRIPTION There may be a short circuit between one of the CAN bus lines and +B when there is no resistance between terminal 22 (CA2H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 7 (CA2L) of the central gateway ECU (network gateway ECU) and termin ...

    Toyota Avalon (XX50) 2019-2022 Owners Manual

    Toyota Avalon (XX50) 2019-2022 Service & Repair Manual

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