Last Modified: 11-29-2007 1.6 J
Service Category: Power Source/Network Section: Networking
Model Year: 2008 Model: Sequoia Doc ID: RM000002VTL002X
Title: NETWORKING: CAN COMMUNICATION SYSTEM: DESCRIPTION (2008 Sequoia)

Open in CAN Main Wire

DESCRIPTION

There may be an open circuit in the CAN main wire and/or the DLC3 branch wire when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 69 Ω or higher.

Symptom

Trouble Area

Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is 69 Ω or higher.
  • CAN main wire and connector
  • No. 1 junction connector
  • No. 2 junction connector
  • No. 4 junction connector*1
  • ECM
  • Combination Meter ECU

HINT:

*1: w/ Air suspension system

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Operating the ignition switch, any other switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

PROCEDURE

1.

DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

(a) Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and the branch wire.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

NEXT

2.

CHECK DLC3

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

Result

Tester Connection

Switch Condition

Measured Resistance

Proceed to

H19-6 (CANH) - H19-14 (CANL)

Ignition switch off

108 to 132 Ω

OK

133 Ω or higher

NG

NOTICE:

When the measured value is 132 Ω or higher and a CAN communication system DTC is output, there may be a problem besides disconnection of the DLC3 branch wire. For that reason, troubleshooting should be performed again from "How to Proceed with Troubleshooting" NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING (2008 Sequoia) after repairing the trouble area.
OK

3.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 1 JUNCTION CONNECTOR - ECM)

(a) Disconnect the H101 No. 1 junction connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H101-1 (CANH) - H101-2 (CANL)

Ignition switch off

108 to 132 Ω
OK

4.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 1 JUNCTION CONNECTOR - COMBINATION METER ECU)

(a) Disconnect the H91 No. 1 junction connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H91-1 (CANH) - H91-2 (CANL)

Ignition switch off

108 to 132 Ω

Result

Result

Proceed to

OK

A

NG (w/o Air suspension system)

B

NG (w/ Air suspension system)

C
A

6.

CONNECT CONNECTOR

(a) Reconnect the H101 No. 1 junction connector.

NEXT

7.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 2 JUNCTION CONNECTOR - ECM)

(a) Disconnect the H99 No. 2 junction connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H99-1 (CANH) - H99-2 (CANL)

Ignition switch off

108 to 132 Ω
OK

8.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)

(a) Disconnect the H100 No. 2 junction connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H100-1 (CANH) - H100-2 (CANL)

Ignition switch off

108 to 132 Ω
OK

10.

CONNECT CONNECTOR

(a) Reconnect the H99 No. 1 junction connector.

NEXT

11.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM - NO. 2 JUNCTION CONNECTOR)

(a) Disconnect the A27 ECM connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

A27-10 (CANH) - A27-11 (CANL)

Ignition switch off

108 to 132 Ω

Result

Result

Proceed to

NG

A

OK (for 2UZ-FE)

B

OK (for 3UR-FE)

C
A

13.

CONNECT CONNECTOR

(a) Reconnect the H91 No. 1 junction connector.

NEXT

14.

CHECK OPEN IN CAN BUS MAIN WIRE (COMBINATION METER ECU - NO. 1 JUNCTION CONNECTOR)

(a) Disconnect the H37 combination meter ECU connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H37-33 (CANH) - H37-34 (CANL)

Ignition switch off

108 to 132 Ω
OK

16.

CONNECT CONNECTOR

(a) Reconnect the H91 No. 1 junction connector.

NEXT

17.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 4 JUNCTION CONNECTOR - COMBINATION METER ECU)

(a) Disconnect the O41 No. 4 junction connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

O41-1 (CANH) - O41-7 (CANL)

Ignition switch off

108 to 132 Ω
OK

18.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 1 JUNCTION CONNECTOR - NO. 4 JUNCTION CONNECTOR)

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

O41-2 (CANH) - O41-8 (CANL)

Ignition switch off

108 to 132 Ω
OK

20.

CONNECT CONNECTOR

(a) Reconnect the O41 No. 4 junction connector.

NEXT

21.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (COMBINATION METER ECU - NO. 4 JUNCTION CONNECTOR)

(a) Disconnect the H37 combination meter ECU connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

H37-33 (CANH) - H37-34 (CANL)

Ignition switch off

108 to 132 Ω
OK