Pre-Collision System

PRE-COLLISION: PRE-COLLISION SYSTEM: C1A6A: Infrared Signal Circuit
C1A6A - Infrared Signal Circuit

DESCRIPTION

The driving support ECU uses the front millimeter wave radar sensor, driver monitor camera and object recognition camera to detect obstacles in front of and behind the vehicle, and detect the direction that the driver's head is facing. Based on this information, the driving support ECU sends pre-collision control operation signals.

The headlight's hi beam part is equipped with a near infrared ray filter. While driving at night, when the light conditions surrounding the vehicle are the darker than a certain threshold, the headlights are automatically changed to hi beam mode, and the near infrared ray filter is activated. By emitting near infrared rays toward the area in front of the vehicle, the object recognition camera's ability to detect obstacles is improved.

HINT
Even if hi beam mode is automatically set, occupants in oncoming vehicles will not be affected as the near infrared filter is activated.

When there is a malfunction in the wire harness between the object recognition ECU and headlight, and a headlight (Lo beam) malfunction signal is received, this DTC is output.

This DTC is also output from the dynamic radar cruise control system.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK HEADLIGHT

(a) Turn the power switch ON (READY).

(b) Check that the headlights (Lo/Hi) turn on.

OK:

Headlights turn on normally.

HINT
If the near infrared ray filter is stuck in the activated position, the headlights will seem as if they are not in Hi beam mode (only a dim, red light will be emitted). If this occurs, it is necessary to replace the headlight assembly.

Result

B -- REPAIR OR REPLACE HEADLIGHT Removal

C -- REPAIR OR REPLACE HEADLIGHT Removal
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (OBJECT RECOGNITION ECU - HEADLIGHT)

(a) Disconnect the p1 ECU connector.

(b) for LH:

(1) Disconnect the B1 headlight connector.

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

Standard resistance:

(1) Disconnect the B11 headlight connector.

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

Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. PERFORM ACTIVE TEST USING TECHSTREAM (NEAR INFRARED RAY FILTER)

(a) Using the Techstream, enter the following menus: Body Electrical / Pre-Collision 2 / Active Test.

Pre-Collision 2

OK:

Near infrared ray filter operates normally.

HINT
When the near infrared ray filter is operated, the headlights illuminate in a faint red color.

Result

B -- REPLACE HEADLIGHT Removal

C -- REPLACE HEADLIGHT Removal
A -- Continue to next step.

4. CHECK OBJECT RECOGNITION ECU

(a) Reconnect the p1 ECU connector.

(b) Disconnect the B1*1 and B11*2 headlight connectors.

HINT
*1: for LH

*2: for RH

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

Standard resistance:

NG -- REPLACE OBJECT RECOGNITION ECU Removal
OK -- Continue to next step.

5. CHECK HEADLIGHT (NEAR INFRARED RAY FILTER SIGNAL)

(a) Reconnect the B1*1 and B11*2 headlight connectors.

HINT
*1: for LH

*2: for RH

(b) Using the Techstream, enter the following menus: Body Electrical / Pre-Collision 2 / Active Test.

(c) Select "Infrared Signal Status", and perform the Active Test.

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

Standard voltage:

Result

B -- REPLACE HEADLIGHT Removal

C -- REPLACE HEADLIGHT Removal

A -- REPLACE OBJECT RECOGNITION ECU Removal