Toyota Sequoia (2005). Manual - part 524

I03343

I03344

I03345

I03977

ECU

ECU

ECU

ECU

ECU

ECU

Open

Open

ECU

ECU

Open

ECU

Disconnection (DTC is detected)

Open (DTC is detected)

Open (DTC is not detected)

I03346

Body ECU

Open

Open

Detects the DTCs for the 
communication stop of the 
3 ECUs.

Example

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

DI–1891

2085

3.

DIAGNOSIS SYSTEM

(a)

If a DTC for an ECU communication stop is indicated, a
connector may be disconnected or there may be open cir-
cuits on 2 or more communication buses. When there is
an open circuit on only 1 communication bus, no DTC will
be detected.

(b)

If 2 communication buses are open at the position shown
in the illustration, DTCs for the ECU communication stop
between these 2 buses are indicated.

DI3IO–11

Customer Problem Analysis

Vehicle Brought to Workshop

Problem Symptom Confirmation

Symptom Simulation

Problem does not
occur

Check DTC

Normal code

Problem Symptoms Table

Identification of Problem

Repair

Confirmation Test

End

Titles inside

are titles of pages in this

manual, with the page number indicated in
the bottom portion. See the indicated pages
for detailed explanations.

1

2

3

4

6

8

P. 

IN–24

*1

P. 

DI–1893

P. 

DI–1904

Malfunction code

Problem
occurs

Circuit Inspection

P. 

DI–1908

 – 

DI–1952

See page

Body control system

Driver door control system

Passenger door control system

System

DI–1682

DI–1780

DI–1816

DI–1610

Step 4, 8: Diagnostic steps permitting the use of the hand–held tester.

*1

5

7

Combination meter system

Slide roof control system

DI–1662

DI–1852

Back door control system

Power seat control system
w/ Driving position memory

DI–1505

Supplemental restraint system

Air conditioning system

DI–1126

DI–2301

DI–1892

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

2086

HOW TO PROCEED WITH TROUBLESHOOTING

Perform troubleshooting in accordance with the procedure on the following page.

DI3IP–10

MULTIPLEX COMMUNICATION SYSTEM Check Sheet

Inspector’s name:

Customer’s Name

VIN

Production Date

Licence Plate No.

Odometer Reading

             /               /

km
mile

Weather Conditions
When Problem
Occurred

Frequency Problem Occurs

Weather

                              /                                /

 Once only

Brought in

Malfunction
System

Outdoor Temperature

 Fine   

   

 Cloudy     

 

Rainy     

 

Snowy

 Various/Others

 Hot       

 

Warm         Cool

 Cold (Approx.     

°

F (     

°

C))

 Constant          Sometimes (    times per     day, month)

 Driver Door Control System

 Passenger Door Control System

 

Combination Meter System

 Body Control System

 

Back Door Control System

 

Slide Roof Control System

 

Power Seat Control System (w/ Driving Position Memory)

 

Supplemental Restraint System

 

Air Condition System

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

DI–1893

2087

CUSTOMER PROBLEM ANALYSIS CHECK

DIDFA–01

I27698

B5

B6

B7

DI–1894

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

2088

TERMINALS OF ECU

1.

CHECK BODY ECU

(a)

Disconnect the B5, B6 and B7 ECU connectors.

(b)

Measure the resistance or voltage of each terminal of the wire harness side connector.
Standard:

Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

BDR (B6–2) – 

Body ground

L–W – Body ground

+B (BATT) power supply

Always

10 to 14 V

IG (B7–6) – Body ground

B–R – Body ground

Ignition power supply

Ignition switch ON

10 to 14 V

ACC (B7–10) – 

Body ground

GR – Body ground

ACC power supply

Ignition switch ACC

10 to 14 V

OBD2 (B5–2) – 

Body ground

G–R – Body ground

Bus ”+” line

During transmission

Pulse generation

S+B (B6–1) – Body ground

W–L – Body ground

+B (BATT) power supply

Always

10 to 14 V

BECU (B6–5) – 

Body ground

W–R – Body ground

+B (BATT) power supply

Always

10 to 14 V

WIG (B7–5) – Body ground

L–Y – Body ground

Ignition power supply

Ignition switch ON

10 to 14 V

MPX3 (B7–20) – 

Body ground

G–O – Body ground

MPX line

Always

10 k

Ω

 or higher

MPX2 (B5–24) – 

Body ground

L–Y – Body ground

MPX line

Always

10 k

Ω

 or higher

MPX1 (B7–22) – 

Body ground

W–L – Body ground

MPX line

Always

10 k

Ω

 or higher

GND1 (B6–6) – 

Body ground

W–B – Body ground

Ground

Always

Below 1 

Ω

PRG – GND1 

(B5–5 – B6–6)

V – W–B

Wireless transmitter signal

ground

Wireless door look receiver

communication circuit

–

RDA – GND1 

(B5–4 – B6–6)

R–G – W–B

Wireless transmitter signal

input

Wireless door lock control

system is operated

Below 1 V

RDA – GND1 

(B5–4 – B6–6)

R–G – W–B

Wireless transmitter signal

input

Wireless door lock control

system is not operated

10 to 14 V

GSW

(B6–16)

GR–R

Air bag sensor commu-

nication signal

Air bag sensor commu-

nication circuit

–

CLTS (*1)  – GND1

(B6–12 – B6–6)

Y – W–B

Automatic light control sen-

sor (Signal)

Ignition switch OFF

Below 1 V

CLTS (*1)  – GND1

(B6–12 – B6–6)

Y – W–B

Automatic light control sen-

sor (Signal)

Ignition switch ON

Signal waveform

CLTE (*1) – GND1 

(B6–3 – B6–6)

BR – W–B

Automatic light control sen-

sor (Ground)

Always

Below 1 V