Last Modified: 11-29-2007 1.6 J
Service Category: Power Source/Network Section: Networking
Model Year: 2008 Model: Sequoia Doc ID: RM000002VTG002X
Title: NETWORKING: CAN COMMUNICATION SYSTEM: DESCRIPTION (2008 Sequoia)

Open in One Side of CAN Branch Line

DESCRIPTION

If 2 or more ECUs and/or sensors do not appear on the Techstream "CAN Bus Check" screen, one side of the CAN branch wire may be open. (One side of the CANH [branch wire]/CANL [branch wire] of the ECU and/or sensor is open.)

Symptom

Trouble Area

2 or more ECUs and/or sensors do not appear on Techstream "CAN Bus Check" screen.
  • One side of CAN branch wire is open
  • Main body ECU
  • Skid control ECU
  • Steering angle sensor
  • Center airbag sensor
  • Bus buffer ECU*1
  • Air conditioning amplifier
  • 4WD control ECU*2
  • Suspension control ECU*3
  • Distance control ECU*4
  • Power steering ECU

HINT:

  • *1: w/ Bus Buffer ECU
  • *2: w/ 4WD
  • *3: w/ Air suspension system
  • *4: w/ Dynamic laser cruise control

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

  • Perform the following inspection for the ECUs (sensors) which are not displayed on the Techstream. If a malfunction cannot be identified, perform the following inspections for the ECUs (sensors) connected to the CAN communication system.
  • Do not remove the combination meter and ECM, as they are the end parts of the circuit. If removed, CAN communication will not be possible.
  • The open circuit confirmation of the combination meter, ECM and main wire is performed in the Check CAN Bus Line procedure of "How to Proceed with Troubleshooting". This inspection only has procedures for checking for an open circuit on one side of the CAN branch wire.

PROCEDURE

1.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (MAIN BODY ECU)

(a) Disconnect the H2 main body ECU connector.

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

Main Body not displayed on Techstream.

A

Several ECUs and sensors other than Main Body not displayed on Techstream.

B
A

2.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (MAIN BODY ECU BRANCH WIRE)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H2-5 (CANH) - H2-6 (CANL)

Ignition switch off

54 to 69 Ω
OK

4.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SKID CONTROL ECU)

(a) Disconnect the A19 skid control ECU connector.

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

ABS/VSC/TRC not displayed on Techstream.

A

Several ECUs and sensors other than ABS/VSC/TRC not displayed on Techstream.

B
A

5.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SKID CONTROL ECU BRANCH WIRE)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

A19-5 (CANH) - A19-4 (CANL)

Ignition switch off

54 to 69 Ω
OK

7.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (STEERING ANGLE SENSOR)

(a) Disconnect the H6 steering angle sensor connector.

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

Steering Angle Sensor not displayed on Techstream.

A

Several ECUs and sensors other than Steering Angle Sensor not displayed on Techstream.

B
A

8.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (STEERING ANGLE SENSOR BRANCH WIRE)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H6-10 (CANH) - H6-9 (CANL)

Ignition switch off

54 to 69 Ω
OK

10.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (BUS BUFFER ECU)

NOTICE:

For vehicles without bus buffer ECU, go to "Check for Open in One Side of CAN Branch Wire (Center Airbag Sensor)".

(a) Disconnect the H66 bus buffer ECU connector.

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

Accessory Gateway not displayed on Techstream.

A

Several ECUs and sensors other than Accessory Gateway not displayed on Techstream.

B
A

11.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (BUS BUFFER ECU BRANCH WIRE)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H66-3 (CAN+) - H66-2 (CAN-)

Ignition switch off

54 to 69 Ω
OK

13.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR)

(a) Disconnect the H56 center airbag sensor connector.

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

SRS Airbag not displayed on Techstream.

A

Several ECUs and sensors other than SRS Airbag not displayed on Techstream.

B
A

14.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR BRANCH WIRE)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H56-13 (CANH) - H56-22 (CANL)

Ignition switch off

54 to 69 Ω
OK

16.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER STEERING ECU)

(a) Disconnect the H38 power steering ECU connector.

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

Power Steering not displayed on Techstream.

A

Several ECUs and sensors other than Power Steering not displayed on Techstream.

B
A

17.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER STEERING ECU BRANCH WIRE)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H38-8 (CANH) - H38-3 (CANL)

Ignition switch off

54 to 69 Ω
OK

19.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (DISTANCE CONTROL ECU)

NOTICE:

For vehicles without Dynamic laser cruise control system, go to "Check for Open in One Side of CAN Branch Wire (Suspension Control ECU)".

(a) Disconnect the A43 distance control ECU connector.

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

Cruise Control (ACC) not displayed on Techstream.

A

Several ECUs and sensors other than Cruise Control (ACC) not displayed on Techstream.

B
A

20.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (DISTANCE CONTROL ECU BRANCH WIRE)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

A43-8 (CANH) - A43-9 (CANL)

Ignition switch off

54 to 69 Ω
OK

22.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SUSPENSION CONTROL ECU)

NOTICE:

For vehicles without Air suspension system, go to "Check for Open in One Side of CAN Branch Wire (4WD Control ECU)".

(a) Disconnect the O18 suspension control ECU connector (w/ AVS) or O19 suspension control ECU connector (w/o AVS).

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

Air Suspension not displayed on Techstream.

A

Several ECUs and sensors other than Air Suspension not displayed on Techstream.

B
A

23.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SUSPENSION CONTROL ECU BRANCH WIRE)

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

Standard Resistance:

w/ AVS

Tester Connection

Switch Condition

Specified Condition

O18-30 (CANH) - O18-29 (CANL)

Ignition switch off

54 to 69 Ω

w/out AVS

Tester Connection

Switch Condition

Specified Condition

O19-29 (CANH) - O19-28 (CANL)

Ignition switch off

54 to 69 Ω
OK

25.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (4WD CONTROL ECU)

NOTICE:

For vehicles without 4WD, go to "Check for Open in One Side of CAN Branch Wire (Air Conditioning Amplifier Branch Wire)".

(a) Disconnect the A28 4WD control ECU connector.

(b) Select "CAN Bus Check" on the Techstream NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM (2008 Sequoia) .

Result

Result

Proceed to

Four Wheel Drive Control not displayed on Techstream.

A

Several ECUs and sensors other than Four Wheel Drive Control not displayed on Techstream.

B
A

26.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (4WD CONTROL ECU BRANCH WIRE)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

A28-19 (CANH) - A28-20 (CANL)

Ignition switch off

54 to 69 Ω
OK

28.

CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AIR CONDITIONING AMPLIFIER BRANCH WIRE)

(a) Disconnect the H24 air conditioning amplifier connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H2-11 (CANH) - H2-12 (CANL)

Ignition switch off

54 to 69 Ω
A