Multiplex Control System: Other Lexus LS II

BODY ELECTRONIC CONTROL UNIT (ECU)

The body ECU, the master unit of the multiplex control system, has communication and control capabilities. The body ECU processes data signals received from all ECUs and sends electrical load data signals to each ECU. The main function of the body ECU is to control the anti-theft system and control the locking of the front and rear passenger doors.

DRIVER'S DOOR ELECTRONIC CONTROL UNIT (ECU)

The driver's door ECU is a slave unit of the body ECU and has communication and control capabilities. The driver's door ECU uses data signals from body ECU to control on/off operation of electrical loads. The main function of the driver's door ECU is to control driver's door power window, driver's door lock and driver's door outside mirror (if equipped with driver's memory system).

FRONT PASSENGER'S DOOR ELECTRONIC CONTROL UNIT (ECU)

The front passenger's door ECU is a slave unit of the body ECU and has communication and control capabilities. The front passenger's door ECU uses data signals from body ECU to control on/off operation of electrical loads. The main function of the front passenger's door ECU is to control front passenger door power window, front passenger door lock and front passenger door outside mirror (if equipped with driver's memory system).

TILT/TELESCOPIC ELECTRONIC CONTROL UNIT (ECU)

The tilt/telescopic ECU is a slave unit of the body ECU and has communication and control capabilities. The tilt/telescopic ECU uses data signals from body ECU to control on/off operation of electrical loads. The main function of the tilt/telescopic ECU is to control the driver's memory system.

* PLEASE READ FIRST *

PIN VOLTAGE TESTS

Note. Perform this procedure only if appropriate test under TESTING has been performed and system still does not operate.

BODY ECU

Disconnect body ECU connectors. Measure voltage between the following terminals of body ECU connectors. see scheme 4 If voltage is not as specified, repair wiring harness or replace components as necessary. If voltages are as specified, replace body ECU and retest system.

A8 & D16

During all conditions, voltage should be 10-14 volts.

A9 & D16

With ignition switch in ON position and wiper switch in INT position, voltage should change from 10-14 volts to less than one volt.

With ignition switch in ON position and wiper switch in OFF position, voltage should be less than one volt.

With ignition switch in ON position and wiper switch is turned from ON to OFF position, voltage should be 10-14 volts for 2.5 seconds.

A15 & D16

With ignition switch in ACC position, voltage should be 10-14 volts.

A20 & Ground

During all conditions, voltage should be less than one volt.

B2 & D16

With right rear door open and all others doors closed, voltage should be less than 2 volts.

With left rear door open and all others doors closed, voltage should be less than 2 volts.

With all doors closed, voltage should be 10-14 volts.

B7 & D16

With front passenger door opened, voltage should be 2-6 volts.

With front passenger door closed, voltage should be less than one volt.

B9 & D16

With ignition switch in ON position, voltage should be 10-14 volts.

B18 & D16

With right rear power window switch in UP position, voltage should be 10-14 volts.

With right rear power window switch in NEUTRAL position, voltage should be less than one volt.

B19 & D16

With right rear power window switch in DOWN position, voltage should be 10-14 volts.

With right rear power window switch in NEUTRAL position, voltage should be less than one volt.

C1 & D16

With anti-theft system set, luggage compartment door key lock and unlock switch in OFF position, and luggage compartment door open, voltage should change from 10-14 volts to less than one volt.

C2 & D16

With ignition switch in ACC position, voltage should be less than one volt.

With anti-theft system set and engine hood opened, voltage should be 10-14 volts.

C3 & D16

With ignition switch in ON position and light control switch in TAIL position, voltage should be less than 2 volts.

With ignition switch in ON position and light control switch in OFF position, voltage should be 10-14 volts.

C8 & D16

With ignition switch in ON position and light control switch in HEAD position, voltage should be less than 2 volts.

With ignition switch in ON position and light control switch in OFF position, voltage should be 10-14 volts.

C12 & D16

With SECURITY indicator light illuminated, voltage should be 3-6 volts.

Without SECURITY indicator light illuminated, voltage should be less than one volt.

D1 & D16

During all conditions, voltage should be 10-14 volts.

D3 & D16

With anti-theft system set, luggage compartment door key lock and unlock switch in OFF position, and luggage compartment door open, voltage should change from 10-14 volts to less than one volt.

D4 & D16

During all conditions, voltage should be 10-14 volts.

D5 & D16

With door lock control switch in LOCK position, voltage should be 10-14 volts for 250 milliseconds.

With door lock control switch in NEUTRAL position, voltage should be less than one volt.

D6 & D16

With key in ignition switch and door lock control switch in LOCK position, voltage should be 10-14 volts for 250 milliseconds.

With door lock control switch in NEUTRAL position, voltage should be less than one volt.

D7 & D16

With luggage compartment door opener switch in ON position, voltage should be 10-14 volts for 250 milliseconds.

D9 & D16

With driver's door opened, voltage should be 2-6 volts.

With driver's door closed, voltage should be less than one volt.

D13 & D16

With left rear power window switch in UP position, voltage should be 10-14 volts.

With left rear power window switch in NEUTRAL position, voltage should be less than one volt.

D14 & D16

With left rear power window switch in DOWN position, voltage should be 10-14 volts.

With left rear power window switch in NEUTRAL position, voltage should be less than one volt.

D16 & Ground

During all conditions, voltage should be less than one volt.

DRIVER'S DOOR ECU

Disconnect driver's door ECU connectors. Measure voltage between the following terminals of driver's door ECU connectors. see scheme 5 If voltages are not as specified, repair wiring harness or repl ace components as necessary. If voltages are as specified, replace driver's door ECU and retest system.

A2 & C10

With outside left rear view mirror in NEUTRAL position, voltage should be less than one volt.

With outside left rear view mirror operating to LEFT or UP position, voltage should be less than one volt.

With outside left rear view mirror operating to DOWN or RIGHT position, voltage should be 10-14 volts.

A3 & C10

With outside left rear view mirror in NEUTRAL position, voltage should be less than one volt.

With outside left rear view mirror operating to LEFT or UP position, voltage should be less than one volt.

With outside left rear view mirror operating to LEFT position, voltage should be 10-14 volts.

A5 & C10

With ignition switch in OFF position and after 30 seconds from closing door, voltage should be less than one volt.

With ignition switch in ON position, voltage should be 10-14 volts.

A6 & C10

With driver's door closed, voltage should be 10-14 volts.

With driver's door opened, voltage should be less than one volt.

A10 & C14

With shoulder belt adjust switch in OFF position, voltage should be 10-14 volts.

With shoulder belt adjust switch in DOWN position, voltage should be less than one volt.

A12 & C10

With outside left rear view mirror in NEUTRAL position, voltage should be less than one volt.

With outside left rear view mirror operating to DOWN or RIGHT position, voltage should be less than one volt.

With outside left rear view mirror operating to UP position, voltage should be 10-14 volts.

A15 & C10

During all conditions, voltage should be 10-14 volts.

B2 & C10

With master window lock switch in UNLOCK position, voltage should be less than one volt.

With master window lock switch in LOCK position, voltage should be 10-14 volts.

B3 & C10

With door lock control switch in NEUTRAL position, voltage should be 10-14 volts.

With door lock control switch in LOCK position, voltage should be less than one volt.

B4 & C10

With ignition switch in ON position and left rear power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and left rear power window switch in UP position, voltage should be 10-14 volts.

B5 & C10

With ignition switch in ON position and right rear power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and right rear power window switch in UP position, voltage should be 10-14 volts.

B6 & C10

With ignition switch in ON position and right front power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and right front power window switch in UP position, voltage should be 10-14 volts.

B7 & C10

With ignition switch in ON position and left front power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and left front power window switch in UP position, voltage should be 10-14 volts.

B8 & C10

With auto down switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and auto down switch in ON position, voltage should be 10-14 volts.

B10 & C10

With ignition switch in OFF position, voltage should be less than one volt.

With ignition switch in ON position, voltage should be 10-14 volts.

B11 & C10

With master door lock control switch in NEUTRAL position, voltage should be 10-14 volts.

With master door lock control switch in UNLOCK position, voltage should be less than one volt.

B12 & C10

With ignition switch in ON position and left rear power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and left rear power window switch in DOWN position, voltage should be 10-14 volts.

B13 & C10

With ignition switch in ON position and right rear power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and right rear power window switch in DOWN position, voltage should be 10-14 volts.

B14 & C10

With ignition switch in ON position and right front power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and right front power window switch in DOWN position, voltage should be 10-14 volts.

B15 & C10

With ignition switch in ON position and left front power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and left front power window switch in DOWN position, voltage should be 10-14 volts.

C1 & C10

During all conditions, voltage should be 10-14 volts.

C2 & C10

During all conditions, voltage should be 10-14 volts.

C3 & C10

With driver's door locked, voltage should be 10-14 volts.

With driver's door unlocked, voltage should be less than one volt.

C4 & C10

With driver's door key lock and unlock switch in NEUTRAL position, voltage should be less than one volt.

With driver's door key lock and unlock switch in LOCK position, voltage should be 10-14 volts.

C5 & C10

With shoulder belt adjust switch in OFF position, voltage should be 10-14 volts.

With shoulder belt adjust switch in UP position, voltage should be less than one volt.

C6 & C10

With set switch in OFF position, voltage should be 10-14 volts.

With set switch in ON position, voltage should be less than one volt.

C7 & C10

With memory switch No. 1 in OFF position, voltage should be 10-14 volts.

With memory switch No. 1 in ON position, voltage should be less than one volt.

C8 & C10

With left front door lock in NEUTRAL position, voltage should be less than one volt.

With left front door lock in UNLOCK position, voltage should be less than one volt.

With left front door lock in LOCK position, voltage should be 10-14 volts.

C9 & C10

With left front power window in NEUTRAL position, voltage should be less than one volt.

With left front power window in UP position, voltage should be 10-14 volts.

C10 & C11

With ignition switch in ON position, voltage should be 10-14 volts.

C10 & C12

During all conditions, voltage should be 10-14 volts.

C10 & C13

With driver's door key lock and unlock switch in NEUTRAL position, voltage should be less than one volt.

With driver's door key lock and unlock switch in UNLOCK position, voltage should be 10-14 volts.

C10 & Ground

During all conditions, voltage should be less than one volt.

C11 & Ground

During all conditions, voltage should be less than one volt.

C10 & C16

With memory switch No. 2 in OFF position, voltage should be 10-14 volts.

With memory switch No. 2 in ON position, voltage should be less than one volt.

C10 & C17

With left front door lock in NEUTRAL position, voltage should be less than one volt.

With left front door lock in LOCK position, voltage should be less than one volt.

With left front door lock in UNLOCK position, voltage should be 10-14 volts.

C10 & C18

With left front power window in NEUTRAL position, voltage should be less than one volt.

With left front power window in DOWN position, voltage should be 10-14 volts.

FRONT PASSENGER'S DOOR ECU

Disconnect front passenger's door ECU connectors. Measure voltage between the following terminals of passenger's door ECU connectors. see scheme 6 If voltages are not as specified, repair wiring harness or replace components as necessary. If voltages are as specified, replace passenger's door ECU and retest system.

A2 & B10

With outside right rear view mirror in NEUTRAL position, voltage should be less than one volt.

With outside right rear view mirror operating to LEFT or UP position, voltage should be less than one volt.

With outside right rear view mirror operating to DOWN or RIGHT position, voltage should be 10-14 volts.

A3 & B10

With outside right rear view mirror in NEUTRAL position, voltage should be less than one volt.

With outside right rear view mirror operating to LEFT or UP position, voltage should be less than one volt.

With outside right rear view mirror operating to LEFT position, voltage should be 10-14 volts.

A5 & B10

With ignition switch in OFF position and after 30 seconds from closing door, voltage should be less than one volt.

With ignition switch in ON position, voltage should be 4-6 volts.

A6 & B10

With right front door closed, voltage should be 10-14 volts.

With right front door opened, voltage should be less than one volt.

A11 & B10

With ignition switch in ON position, voltage should be 10-14 volts.

A12 & B10

With outside right rear view mirror in NEUTRAL position, voltage should be less than one volt.

With outside right rear view mirror operating to DOWN or RIGHT position, voltage should be less than one volt.

With outside right rear view mirror operating to UP position, voltage should be 10-14 volts.

A15 & B10

During all conditions, voltage should be 10-14 volts.

B3 & B10

With right front door locked, voltage should be 10-14 volts.

With right front door unlocked, voltage should be less than one volt.

B4 & B10

With right front door key lock and unlock switch in NEUTRAL position, voltage should be 10-14 volts.

With right front door key lock and unlock switch in LOCK position, voltage should be less than one volt.

B5 & B10

With right front door lock control switch in NEUTRAL position, voltage should be 10-14 volts.

With right front door lock control switch in LOCK position, voltage should be less than one volt.

B6 & B10

With ignition switch in OFF position, voltage should be less than one volt.

With ignition switch in ON position, voltage should be 10-14 volts.

B7 & B10

With right front power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and right front power window switch in UP position, voltage should be 10-14 volts.

B9 & B10

With right front power window in NEUTRAL position, voltage should be less than one volt.

With right front power window operating to DOWN position, voltage should be less than one volt.

With right front power window operating to UP position, voltage should be 10-14 volts.

B10 & Ground

During all conditions, voltage should be less than one volt.

B10 & B13

With right front door key lock and unlock switch in NEUTRAL position, voltage should be 10-14 volts.

With right front door key lock and unlock switch in UNLOCK position, voltage should be less than one volt.

B10 & B14

With right front door lock control switch in NEUTRAL position, voltage should be 10-14 volts.

With right front door lock control switch in UNLOCK position, voltage should be less than one volt.

B10 & B15

With ignition switch in OFF position, voltage should be less than one volt.

With ignition switch in ON position, voltage should be 10-14 volts.

B10 & B16

With right front power window switch in NEUTRAL position, voltage should be less than one volt.

With ignition switch in ON position and right front power window switch in DOWN position, voltage should be 10-14 volts.

B10 & B18

With right front power window in NEUTRAL position, voltage should be less than one volt.

With right front power window operating to UP position, voltage should be less than one volt.

With right front power window operating to DOWN position, voltage should be 10-14 volts.

B11 & Ground

During all conditions, voltage should be less than one volt.

Power Trunk Lid & Fuel Door Release System Wiring Diagram. Scheme 12

Keyless Entry System Wiring Diagram (1 Of 2). Scheme 13

Keyless Entry System Wiring Diagram (2 Of 2). Scheme 14