Vehicle Interior

Terminals Of Ecu

~2min read
TERMINALS OF ECU

1. CHECK DRIVER SIDE JUNCTION BLOCK ASSEMBLY AND MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)


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


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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

A-30 (BECU) - Body ground

-

Battery power supply

Always

11 to 14 V

A-31 (ALTB) - Body ground

-

Battery power supply

Always

11 to 14 V

A-32 (IG) - Body ground

-

Ignition switch power supply

Ignition switch ON

11 to 14 V

A-32 (IG) - Body ground

-

Ignition switch power supply

Ignition switch off

Below 1 V

A-29 (ACC) - Body ground

-

ACC power supply

Ignition switch ACC

11 to 14 V

A-29 (ACC) - Body ground

-

ACC power supply

Ignition switch off

Below 1 V

A-11 (GND1) - Body ground

-

Ground

Always

Below 1 Ω

F10-3 (GND2) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

F9-17 (KSW) - Body ground

B - Body ground

Unlock warning switch input

No key in ignition key cylinder

10 kΩ or higher

F9-17 (KSW) - Body ground

B - Body ground

Unlock warning switch input

Key inserted in ignition key cylinder

Below 1 Ω

If the result is not as specified, there may be a malfunction in the wire harness.

(c) Install the main body ECU (multiplex network body ECU).

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

2F-27 (FLCY) - Body ground

R - Body ground

Front door LH courtesy switch input

Front door LH open

Below 1 V

2F-27 (FLCY) - Body ground

R - Body ground

Front door LH courtesy switch input

Front door LH closed

11 to 14 V

If the result is not as specified, the main body ECU (multiplex network body ECU) or driver side junction block assembly may have a malfunction.

Test yourself

A quick Toyota 4Runner quiz: every answer comes with an explanation and a link to the manual page.