Diagnosis System

DESCRIPTION
1. Pre-collision system data can be read through the vehicle's Data Link Connector 3 (DLC3). When the system seems to be malfunctioning, use the intelligent tester to check for malfunctions and perform repairs.

CHECK DLC3

The seat belt control 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 (CANL And BAT)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CONNECTOR TERMINAL SPECIFICATION

Symbols (Terminal No.)

Terminal Description

Condition

Specified Condition

SIL (7) - SG (5)

Bus "+" line

During transmission

Pulse generation

BAT (16) - Body ground

Battery positive

Always

10 to 14 V

CG (4) - Body ground

Chassis ground

Always

Below 1 Ω

SG (5) - Body ground

Signal ground

Always

Below 1 Ω

CANH (6) - CANL (14)

CAN bus line

Power switch OFF⁽¹⁾

54 to 69 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

NOTE:

⁽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 intelligent tester (with CAN VIM) to the DLC3, turn the power switch ON (IG) and attempt to use the tester. If the screen displays the message UNABLE TO CONNECT TO VEHICLE, there is a problem either with the vehicle or with the tester.

Fig 2: Connecting Cable Of Intelligent Tester (With CAN VIM) To DLC3

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 is probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.

FUNCTION OF WARNING INDICATOR AND MESSAGE

If the pre-collision system is not functioning properly, the driver is warned through the combination meter's master warning indicator, PCS warning indicator and multi-information display warning message.

Fig 3: Identifying Multi-Information Display, Master Warning Indicator And PCS Warning Indicator
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Initial check.
1. The initial check occurs when the power switch is OFF for more than 2 seconds and then turned ON (IG). The initial check consists of a pre-collision system diagnostic check with a duration of approximately 3 seconds.
2. If a malfunction is detected during the initial check, the multi-information display will output "CHECK PCS SYSTEM" or "PCS NOT AVAILABLE NOW".
Constant check.
1. The seat belt control ECU and cruise control ECU (distance control ECU) constantly monitor the pre-collision system for malfunctions after the initial check (approximately 3 seconds after turning the power switch ON (IG).
2. "CHECK PCS SYSTEM" or "PCS NOT AVAILABLE NOW" is displayed on the multi-information display in the combination meter when the constant check detects malfunctions in the pre-collision system.

Review.

PCS WARNING INDICATOR REFERENCE CHART

Master Warning Indicator	Warning Message	Detail	DTC	PCS Warning Indicator
Illuminate	CHECK PCS SYSTEM	This message appears when the seat belt control ECU detects a system malfunction	◦	ON
Illuminate	PCS NOT AVAILABLE NOW	This message appears when the seat belt control ECU is in the fail-safe mode (see FAIL-SAFE CHART )	-	Blinking