Toyota Tacoma (2015-2018) Service Manual: Vehicle Speed Sensor Circuit (C1AA3)

Toyota Tacoma (2015-2018) Service Manual / Cruise Control / Lane Departure Alert System / Vehicle Speed Sensor Circuit (C1AA3)

DESCRIPTION

The forward recognition camera receives vehicle speed signals from the skid control ECU. If the skid control ECU receives a vehicle speed sensor malfunction signal, it informs the forward recognition camera via CAN communication, and DTC C1AA3 is stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1AA3	Vehicle Speed Sensor Circuit	3 seconds after the ignition switch is turned to ON, a signal from the skid control ECU indicating a malfunction in a vehicle speed sensor is detected by the forward recognition camera for 5 seconds or more.	Vehicle stability control system Skid control ECU (brake actuator assembly)1 Skid control ECU (master cylinder solenoid)2 Forward recognition camera

*1: for Vacuum Brake Booster
*2: for Hydraulic Brake Booster

CAUTION / NOTICE / HINT

NOTICE:

When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle. 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.
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PROCEDURE

1.	CHECK DTC OUTPUT (VEHICLE STABILITY CONTROL SYSTEM)

HINT:

If DTC C1AA3 is stored, the vehicle stability control system may be malfunctioning. Check for DTCs related to the vehicle stability control system first.

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Check for DTCs.

for Vacuum Brake Booster
Click here
for Hydraulic Brake Booster
Click here

Result	Proceed to
Vehicle stability control system DTCs are not output	A
Vehicle stability control system DTCs are output (for Vacuum Brake Booster)	B
Vehicle stability control system DTCs are output (for Hydraulic Brake Booster)	C

GO TO VEHICLE STABILITY CONTROL SYSTEM

2.	CHECK DTC OUTPUT

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Chassis / LKA/LDA / Trouble Codes.

(e) Clear the DTCs.

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

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

HINT:

If the following procedure is not performed, the previously output DTC cannot be detected.

(g) Check for DTCs.

Click here

Result	Proceed to
DTC C1AA3 is output	A
DTC C1AA3 is not output	B

USE SIMULATION METHOD TO CHECK

3.	REPLACE FORWARD RECOGNITION CAMERA

(a) Replace the forward recognition camera.

Click here (b) Adjust the forward recognition camera.

(b) Adjust the forward recognition camera.

Click here

4.	CHECK DTC OUTPUT

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Chassis / LKA/LDA / Trouble Codes.

(e) Clear the DTCs.

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

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

HINT:

If the following procedure is not performed, the previously output DTC cannot be detected.

(g) Check for DTCs.

Click here

Result	Proceed to
DTC C1AA3 is output (for Vacuum Brake Booster)	A
DTC C1AA3 is output (for Hydraulic Brake Booster)	B
DTC C1AA3 is not output	C

REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)

REPLACE SKID CONTROL ECU (MASTER CYLINDER SOLENOID)

END (FORWARD RECOGNITION CAMERA WAS DEFECTIVE)

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