Diagnosis System

DESCRIPTION
The ECM controls the cruise control system of the vehicle. The data and DTCs relating to the cruise control system can be read from the DLC3 of the vehicle. If the CRUISE main indicator light does not illuminate after a DTC check, there may be a problem with the cruise control system. Use the intelligent tester to check and solve the problem.

CHECK DLC3

The ECM uses ISO 15765-4 for communication. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.

Fig 1: Identifying DLC3 Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

ECU CONNECTOR TERMINAL SPECIFIED CONDITION

Symbols (Terminals No.)

Terminal Description

Condition

Specified condition

SIL (7) - SG (5)

Bus "+" line

During transmission

Pulse generation

CG (4) - Body ground

Chassis ground

Always

Below 1 Ω

SG (5) - Body ground

Signal ground

Always

Below 1 Ω

BAT (16) - Body ground

Battery positive

Always

11 to 14 V

CANH (6) - CANL (14)

CAN bus line

Ignition switch OFF⁽¹⁾

54 to 69 Ω

CANH(6)-BAT(16)

HIGH-level CAN bus line

Ignition switch OFF⁽¹⁾

6 kΩ or higher

CANH (6) - CG (4)

HIGH-level CAN bus line

Ignition switch OFF⁽¹⁾

200 Ω or higher

CANL (14)-BAT (16)

LOW-level CAN bus line

Ignition switch OFF⁽¹⁾

6 kΩ or higher

CANL (14) - CG (4)

LOW-level CAN bus line

Ignition switch OFF⁽¹⁾

200 Ω or higher

NOTE:

⁽¹⁾	Before measuring the resistance, leave the vehicle as is at least 1 minute and do not operate the ignition switch, any other switches or the doors.

If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

HINT:

Connect the cable of the intelligent tester (with CAN VIM) to the DLC3, turn the ignition switch ON and attempt to use the tester. If the screen displays UNABLE TO CONNECT TO VEHICLE, a problem may be on the vehicle side or tester side.

If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.

Fig 2: Connecting Cable Of Intelligent Tester (With CAN VIM) To DLC3
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CHECK INDICATOR
1. Turn the ignition switch ON.
2. Check that the CRUISE main indicator light illuminates when the cruise control main switch is pushed ON, and that the indicator light turns off when the main switch is pushed OFF.
  If the results are not as specified, inspect the CRUISE main indicator light circuit (see CRUISE MAIN INDICATOR LIGHT CIRCUIT ).
  
  Fig 3: Identifying Cruise Main Indicator Light
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. While driving with cruise control, the ECM activates AUTO CANCEL of the cruise control system when a malfunction in one of the following occurs: vehicle speed sensors, stop light switch or other related parts. When AUTO CANCEL is activated, the CRUISE main indicator light outputs the blinking pattern shown in the illustration. At the same time, data of the malfunction is stored in the ECM as a Diagnostic Trouble Code (DTC).
  
  Fig 4: Indicator Light Blinking Pattern
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002