Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001D1OV
Model Year Start: 2019 Model: GR Corolla Prod Date Range: [06/2018 - 01/2019]
Title: THEFT DETERRENT / KEYLESS ENTRY: THEFT DETERRENT SYSTEM (for Gasoline Model): Power Source Circuit; 2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019]

Power Source Circuit

DESCRIPTION

Based on changes in the power source voltage, the main body ECU (multiplex network body ECU) can detect if the battery has been disconnected and reconnected.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

    Click here 2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (POWER SUPPLY)

(a) Disconnect the 4B instrument panel junction block assembly connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

4B-1 - Body ground

Always

8.5 V or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the main body ECU (multiplex network body ECU).

Click here 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL

*a

Component without harness connected

(Instrument Panel Junction Block Assembly)

-

-

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4B-1 - MB-31 (BECU)

Always

Below 1 Ω
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY