Last Modified: 11-29-2007 1.6 J
Service Category: Power Source/Network Section: Networking
Model Year: 2008 Model: Sequoia Doc ID: RM000002VTJ002X
Title: NETWORKING: CAN COMMUNICATION SYSTEM: DESCRIPTION (2008 Sequoia)

4WD Control ECU Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

4WD Control ECU Communication Stop Mode

When either condition below is met:

  • Four Wheel Drive Control is not displayed on "CAN Bus Check".
  • Applies to "4WD Control ECU Communication Stop Mode" in "DTC Combination Table".
  • Power source or inside 4WD control ECU
  • 4WD control ECU branch wire or connector
  • 4WD control 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 (4WD CONTROL ECU BRANCH WIRE)

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

(b) 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

3.

CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - BATTERY AND BODY GROUND)

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

(b) Disconnect the A29 4WD control ECU connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A29-4 (GND) - Body ground

Always

Below 1 Ω

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A29-3 (IG) - Body ground

Ignition switch ON

11 to 14 V
OK