Toyota Tacoma (2015-2018) Service Manual: Skid Control Buzzer Circuit (C1A4A)

Toyota Tacoma (2015-2018) Service Manual / Cruise Control / Dynamic Radar Cruise Control System(for 2tr-fe) / Skid Control Buzzer Circuit (C1A4A)

DESCRIPTION

Based on dynamic radar cruise control system operation, the forward recognition camera provides warnings to the driver by sounding the skid control buzzer.

DTC C1A4A is stored when a malfunction is detected in the skid control buzzer circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1A4A	Skid Control Buzzer Circuit	While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, the forward recognition camera detects a malfunction in the skid control buzzer circuit for approximately 0.4 seconds or more.	Skid control buzzer Millimeter wave radar sensor assembly Forward recognition camera Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.
When replacing the forward recognition camera, make sure to replace it with a new one. If a device which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle, and as a result, a DTC may be stored.
If the forward recognition camera has been replaced with a new one, be sure to perform Forward Recognition Camera Learning.
Click here
First check the CAN communication system by following How to Proceed with Troubleshooting. After checking that there are no malfunctions in the CAN communication system, proceed with troubleshooting.
Click here

PROCEDURE

1.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Check for DTCs of the pre-collision system.

Click here HINT:

HINT:

The dynamic radar cruise control system only stores DTC C1A4A when the vehicle speed reaches 36 km/h (22 mph), however the pre-collision system stores this DTC at any vehicle speed. If DTC C1A4A is stored by the pre-collision system, perform troubleshooting of the pre-collision system first.

Result	Proceed to
DTC C1A4A is not output	A
DTC C1A4A is output	B

GO TO PRE-COLLISION SYSTEM

2.	CHECK FOR DTCs (RADAR CRUISE 2)

(a) Clear the DTCs.

Click here (b) Make sure that the DTC detection conditions are met.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

Turn the ignition switch to ON.
Turn the dynamic radar cruise control system on using the cruise control main switch (ON-OFF button).
Drive the vehicle at 36 km/h (22 mph) or more for 1 second or more.

Click here NOTICE:

NOTICE:

Perform the Active Test for 1 second or more.

HINT:

Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.

Powertrain > Radar Cruise2 > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Radar Cruise Stop Buzzer	Skid control buzzer (stop sound)	ON or OFF	Buzzer can be heard
Radar Cruise Approach Alarm Buzzer	Skid control buzzer (approach sound)	ON or OFF	Buzzer can be heard

(d) Check for DTCs.

Click here

Result	Proceed to
DTC C1A4A is not output	A
DTC C1A4A is output	B

USE SIMULATION METHOD TO CHECK

3.	INSPECT TERMINAL VOLTAGE

(a) Disconnect the skid control buzzer connector.

*a	Front view of wire harness connector (to Skid Control Buzzer)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
N38-2 (IG1) - Body ground	Ignition switch ON	11 to 14 V
N38-2 (IG1) - Body ground	Ignition switch off	Below 1 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - BATTERY)

4.	CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER - FORWARD RECOGNITION CAMERA)

(a) Disconnect the N38 skid control buzzer connector.

(b) Disconnect the F46 forward recognition camera connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
N38-1 (BZ) - F46-8 (BZ)	Always	Below 1 Ω
N38-1 (BZ) or F46-8 (BZ) - Body ground	Always	10 kΩ or higher

GO TO STEP 7

5.	REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER - FORWARD RECOGNITION CAMERA)

(a) Repair or replace the harness or connector.

6.	CHECK FOR DTCs (RADAR CRUISE 2)

(a) Clear the DTCs.

Click here (b) Perform the Active Test according to the display on the Techstream.

(b) Perform the Active Test according to the display on the Techstream.

Click here NOTICE:

NOTICE:

Perform the Active Test for 1 second or more.

HINT:

Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.

Powertrain > Radar Cruise2 > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Radar Cruise Stop Buzzer	Skid control buzzer (stop sound)	ON or OFF	Buzzer can be heard
Radar Cruise Approach Alarm Buzzer	Skid control buzzer (approach sound)	ON or OFF	Buzzer can be heard

Click here

Result	Proceed to
DTC C1A4A is not output	A
DTC C1A4A is output	B

END

7.	INSPECT SKID CONTROL BUZZER (CONFIRM BUZZER OPERATION)

(a) Turn the ignition switch to ON.

(b) Check if the skid control buzzer is sounding.

Result	Proceed to
The skid control buzzer does not sound when the ignition switch is ON	A
The skid control buzzer sounds continuously when the ignition switch is ON	B

GO TO STEP 9

8.	INSPECT SKID CONTROL BUZZER (UNIT INSPECTION)

(a) Remove the skid control buzzer.

Click here (b) Inspect the skid control buzzer.

(b) Inspect the skid control buzzer.

Click here

Result	Proceed to
Skid control buzzer is abnormal	A
Skid control buzzer is normal	B

GO TO STEP 10

9.	REPLACE SKID CONTROL BUZZER

(a) Replace the skid control buzzer.

Click here

10.	CHECK FOR DTCs (RADAR CRUISE 2)

(a) Clear the DTCs.

Click here (b) Perform the Active Test according to the display on the Techstream.

(b) Perform the Active Test according to the display on the Techstream.

Click here NOTICE:

NOTICE:

Perform the Active Test for 1 second or more.

HINT:

Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.

Powertrain > Radar Cruise2 > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Radar Cruise Stop Buzzer	Skid control buzzer (stop sound)	ON or OFF	Buzzer can be heard
Radar Cruise Approach Alarm Buzzer	Skid control buzzer (approach sound)	ON or OFF	Buzzer can be heard

Click here

Result	Proceed to
DTC C1A4A is not output	A
DTC C1A4A is output	B

END

11.	REPLACE FORWARD RECOGNITION CAMERA

(a) Replace the forward recognition camera.

Click here (b) Perform forward recognition axis adjustment.

(b) Perform forward recognition axis adjustment.

Click here

12.	CHECK FOR DTCs (RADAR CRUISE 2)

(a) Clear the DTCs.

Click here (b) Perform the Active Test according to the display on the Techstream.

(b) Perform the Active Test according to the display on the Techstream.

Click here NOTICE:

NOTICE:

Perform the Active Test for 1 second or more.

HINT:

Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.

Powertrain > Radar Cruise2 > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Radar Cruise Stop Buzzer	Skid control buzzer (stop sound)	ON or OFF	Buzzer can be heard
Radar Cruise Approach Alarm Buzzer	Skid control buzzer (approach sound)	ON or OFF	Buzzer can be heard

Click here

Result	Proceed to
DTC C1A4A is not output	A
DTC C1A4A is output	B

END (FORWARD RECOGNITION CAMERA WAS DEFECTIVE)

13.	REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

(a) Replace the millimeter wave radar sensor assembly.

Click here (b) Adjust the millimeter wave radar sensor assembly.

(b) Adjust the millimeter wave radar sensor assembly.

Click here

14.	CLEAR DTC (RADAR CRUISE 2)

(a) Clear the DTCs.

Click here

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

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