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 either DTC or CRUISE OK is not displayed on the multi-information display on the combination meter when checking for DTCs, there may be a problem with either the combination meter or the CAN communication system. Use the intelligent tester to check and solve the problem.

CHECK DLC3

The ECU 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

TERMINALS REFERENCE

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

10 to 14 V

CANH (6) - CANL (14)

CAN bus line

Engine switch off⁽¹⁾

54 to 69 Ω

CANH (6) - CG (4)

HIGH-level CAN bus line

Engine switch off⁽¹⁾

200 Ω or higher

CANL (14) - CG (4)

LOW-level CAN bus line

Engine switch off⁽¹⁾

200 Ω or higher

CANH (6) - BAT (16)

HIGH-level CAN bus line

Engine switch off⁽¹⁾

6 kΩ or higher

CANL (14)-BAT (16)

LOW-level CAN bus line

Engine switch off⁽¹⁾

6 kΩ or higher

NOTE:

⁽¹⁾	Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine 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 to the DLC3, turn the engine switch on (IG) and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.

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.

CHECK INDICATOR
1. Turn the engine switch on (IG).
  
  Fig 2: Identifying Cruise Main Indicator Light
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check that the CRUISE main indicator light illuminates when the cruise control main switch is turned on, and that the indicator light turns off when the main switch is turned off. If the results are not as specified, inspect the CRUISE MAIN INDICATOR LIGHT CIRCUIT .
  HINT:
  
  While driving with cruise control, the ECM activates AUTO CANCEL of the cruise control system when a malfunction occurs in one of the following: 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 to the left. At the same time, data of the malfunction is stored as a DTC.
  
  Fig 3: Identifying Blinking Pattern
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002