Diagnosis System

DIAGNOSIS

If the skid control ECU detects a malfunction, it will warn the driver by turning on the ABS, brake and brake control warning lights and slip indicator light. It also warns the driver with the indication on the multi-information display.

The table below indicates which lights will come on when there is a malfunction in a particular function.

Fig 1: Identifying ABS, BRAKE And Brake Control Warning Lights And SLIP Indicator Light

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

LIGHTS INDICATION REFERENCE CHART

Item / Trouble Area	ABS	EBD	BA	TR(A)C	VSC
ABS Warning Light	◦	◦	◦	-	-
Brake Warning Light	-	◦	-	-	-
Brake Control Warning Light (Multi-information Display)	◦	◦	◦	◦	◦
Slip Indicator Light	◦	◦	◦	◦	◦
Multi-information Display	◦	◦	◦	◦	◦
HINT: ◦: Light ON -: Light OFF The DTCs are simultaneously stored in the memory. The DTCs can be read by connecting SST between terminals 13 (TC) and 4 (CG) of the DLC3 and observing the blinking pattern of the ABS, brake control warning lights, or indication on the multi-information display, or by connecting the Techstream. This system has a signal check function. The DTC can be read by connecting the Techstream and observing the blinking pattern of the ABS and brake control warning lights or by reading the multi-information display.

WARNING LIGHT AND INDICATOR LIGHT BULB CHECK

Release the parking brake.

CAUTION: When releasing the parking brake, set chocks to hold the vehicle for safety.

HINT:

When the power switch is turned ON (IG), check that the ABS, brake and brake control warning lights and slip, VSC OFF indicator lights come on until the power switch is turned ON (READY).
If the warning light and indicator light check result is not normal, proceed to troubleshooting for the ABS, brake and brake control warning light circuits, and slip, VSC OFF indicator light circuits.

If the indicator remains on, proceed to troubleshooting for the light circuit below.

TROUBLE AREA REFERENCE CHART

Trouble area	See procedure
ABS warning light circuit	ABS WARNING LIGHT REMAINS ON
Brake warning light circuit	BRAKE WARNING LIGHT REMAINS ON
Brake control warning light circuit	BRAKE CONTROL WARNING LIGHT REMAINS ON
Slip indicator light circuit	SLIP INDICATOR LIGHT REMAINS ON
VSC OFF indicator light circuit	VSC OFF INDICATOR LIGHT REMAINS ON

Fig 2: Identifying ABS, BRAKE, Brake Control Warning Lights, SLIP And VSC OFF Indicator Lights

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CHECK DLC3

HINT:

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

Fig 3: Identifying Terminal Of DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CONNECTOR TERMINAL REFERENCE

Symbols (Terminal No.)

Terminal Description

Condition

Specified Condition

CG (4) - Body ground

Chassis ground

Always

Below 1 Ω

SG (5) - Body ground

Signal ground

Always

Below 1 Ω

SIL (7) - SG (5)

Bus "+" line

During transmission

Pulse generation

BAT (16) - Body ground

Battery positive

Always

10 to 14 V

CANH (6) - CANL (14)

CAN bus line

Power switch OFF⁽¹⁾

54 to 67 Ω

CANH (6) - BAT (16)

HIGH-level CAN bus line

Power switch OFF⁽¹⁾

6 kΩ or higher

CANH (6) - CG (4)

HIGH-level CAN bus line

Power switch OFF⁽¹⁾

200 Ω or higher

CANL (14) - BAT (16)

LOW-level CAN bus line

Power switch OFF⁽¹⁾

6 kΩ or higher

CANL (14) - CG (4)

LOW-level CAN bus line

Power switch OFF⁽¹⁾

200 Ω or higher

⁽¹⁾	Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power 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 Techstream to the DLC3, turn the power 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.