Last Modified: 11-29-2007 1.6 J
Service Category: Power Source/Network Section: Networking
Model Year: 2008 Model: Sequoia Doc ID: RM000002VTK002X
Title: NETWORKING: CAN COMMUNICATION SYSTEM: DESCRIPTION (2008 Sequoia)

Main Body ECU Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Main Body ECU Communication Stop Mode

When either condition below is met:

  • Main Body is not displayed on "CAN Bus Check".
  • Applies to "Main Body ECU Communication Stop Mode" in "DTC Combination Table".
  • Power source or inside main body ECU
  • Main body ECU branch wire or connector (V Bus)
  • Main body ECU

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Operating the ignition switch, any 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 FOR OPEN IN CAN BUS WIRE (MAIN BODY ECU BRANCH WIRE)

(a) Disconnect the H2 main body ECU connector.

(b) 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

3.

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND BODY GROUND)

(a) Reconnect the cable to the negative (-) battery terminal.

(b) Disconnect the DA, DB and DD main body ECU connectors.

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



Standard Resistance:

Tester Connection

Condition

Specified Condition

DD-62 (GND1) - Body ground

Always

Below 1 Ω

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

DA-1 (ALTB) - Body ground

Always

11 to 14 V

DB-13 (BECU) - Body ground
OK