Cruise Control. Dtc C1A11 Front Radar Sensor Incorrect Axial Gap

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect objects in front of the vehicle.
When it is determined that the vehicle is being driven in a straight line or on a gradual curve based on signals from the yaw rate and acceleration sensor, the millimeter wave radar sensor assembly performs self-diagnosis to check if the sensor beam axis has deviated. When the millimeter wave radar sensor assembly beam axis is misaligned, the driving support ECU assembly stores DTC C1A11.
After installing a new millimeter wave radar sensor assembly, if sensor beam axis adjustment is not performed, DTC C1A14 is stored.

DTC No.	DTC Detection Condition	Trouble Area
C1A11	When the vehicle is being driven at a speed of 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, misalignment of the millimeter wave radar sensor assembly is detected for approximately 1 second or more.	Millimeter wave radar sensor assembly Driving support ECU assembly
C1A14	When the vehicle is being driven at a speed of 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, incompletion of the millimeter wave radar sensor beam axis alignment is detected for approximately 1 second or more.	Millimeter wave radar sensor assembly Driving support ECU assembly

INSPECTION PROCEDURE

NOTICE:

When replacing the driving support ECU assembly, 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 driving support ECU assembly will not match the information from the vehicle, and as a result, a DTC may be stored.
When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed (Click here).
When replacing the millimeter wave radar sensor assembly, 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 millimeter wave radar sensor assembly will not match the information from the vehicle, and as a result, a DTC may be stored.
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).

1.CHECK DTC OUTPUT (RADAR CRUISE 2)

Check if the stored DTCs are current DTCs.

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

Enter the following menus: Chassis / Radar Cruise2 / Trouble Codes.

Check for DTCs (Click here).

Result
Result	Proceed to
Current DTC C1A11 is output	A
Current DTC C1A14 is output	B
History DTC C1A11 is output	C

Go to step 13

Go to step 15

A

2.CHECK VEHICLE CONDITION

Check the operating conditions of the vehicle.
HINT:
DTC C1A11 may be stored if the millimeter wave radar sensor assembly beam axis is temporarily misaligned due to the vehicle being overloaded.

Result
Result	Proceed to
Vehicle is not overloaded or being towed	A
Vehicle is overloaded or being towed	B

Go to step 12

A

3.CHECK WHEEL ALIGNMENT

Check the front wheel alignment (toe) (Click here).
HINT:
DTC C1A11 may be stored if the millimeter wave radar sensor assembly beam axis is misaligned due to incorrect wheel alignment (toe).

Result
Result	Proceed to
Front wheel is misaligned (toe)	A
Front wheels are not misaligned (toe)	B

Go to step 7

A

4.ADJUST WHEEL ALIGNMENT

Adjust the alignment (toe) of the wheels (Click here).

NEXT

5.ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Perform millimeter wave radar sensor assembly adjustment (Click here).

NEXT

6.CHECK DTC OUTPUT (RADAR CRUISE2)

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

Enter the following menus: Chassis / Radar Cruise2 / Trouble Codes.

Clear the DTCs (Click here).

Make sure that the DTC detection conditions are met.
HINT:
If the following procedure is not performed, the previously output DTC cannot be detected.
1. Turn the engine switch on (IG).
2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON/OFF).
3. Drive the vehicle at 5 km/h (3 mph) or more for 1 second or more.

Check for DTCs (Click here).

Result
Result	Proceed to
DTC C1A11 is not output	A
DTC C1A11 is output	B

Go to step 16

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

7.CHECK MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Check that the bracket of the millimeter wave radar sensor assembly is not deformed (Click here).
Result
Result
Proceed to
Bracket is not deformed
A
No. 1 millimeter wave radar sensor bracket is deformed
B
The other bracket than No. 1 millimeter wave radar sensor bracket is deformed
C

Go to step 10

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY (Click here)

A

8.ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Perform millimeter wave radar sensor assembly adjustment (Click here).

NEXT

9.CHECK DTC OUTPUT (RADAR CRUISE2)

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

Enter the following menus: Chassis / Radar Cruise2 / Trouble Codes.

Clear the DTCs (Click here).

Make sure that the DTC detection conditions are met.
HINT:
If the following procedure is not performed, the previously output DTC cannot be detected.
1. Turn the engine switch on (IG).
2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON/OFF).
3. Drive the vehicle at 5 km/h (3 mph) or more for 1 second or more.

Check for DTCs (Click here).
Result
Result
Proceed to
DTC C1A11 is not output
A
DTC C1A11 is output
B

Go to step 16

END (NO. 1 MILLIMETER WAVE RADAR SENSOR BRACKET WAS DEFECTIVE)

10.REPLACE NO. 1 MILLIMETER WAVE RADAR SENSOR BRACKET

Replace the No. 1 millimeter wave radar sensor bracket with a new one (Click here).

Perform millimeter wave radar sensor assembly adjustment (Click here).

NEXT

11.CHECK DTC OUTPUT (RADAR CRUISE2)

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

Enter the following menus: Chassis / Radar Cruise2 / Trouble Codes.

Clear the DTCs (Click here).

Make sure that the DTC detection conditions are met.
HINT:
If the following procedure is not performed, the previously output DTC cannot be detected.
1. Turn the engine switch on (IG).
2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON/OFF).
3. Drive the vehicle at 5 km/h (3 mph) or more for 1 second or more.

Check for DTCs (Click here).
Result
Result
Proceed to
DTC C1A11 is not output
A
DTC C1A11 is output
B

REPLACE DRIVING SUPPORT ECU ASSEMBLY (Click here)

END (NO. 1 MILLIMETER WAVE RADAR SENSOR BRACKET WAS DEFECTIVE)

12.ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Return the vehicle to normal operating conditions.

Perform millimeter wave radar sensor assembly adjustment (Click here).

Clear the DTCs (Click here).

END

13.ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Perform millimeter wave radar sensor assembly adjustment (Click here).

NEXT

14.CHECK DTC OUTPUT (RADAR CRUISE2)

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

Enter the following menus: Chassis / Radar Cruise2 / Trouble Codes.

Check for DTCs (Click here).

Make sure that the DTC detection conditions are met.
HINT:
If the following procedure is not performed, the previously output DTC cannot be detected.
1. Turn the engine switch on (IG).
2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON/OFF).
3. Drive the vehicle at 5 km/h (3 mph) or more for 1 second or more.

Check for DTCs (Click here).

Result
Result	Proceed to
DTC C1A14 is not output	A
DTC C1A14 is output	B

Go to step 18

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

15.CLEAR DTC

Check for DTCs related to misalignment of millimeter wave radar sensor assembly.
HINT:
If only history DTCs are stored, they may have stored due to a temporarily condition such as overloading of the vehicle, and the system returned to normal when beam axis learning was performed.

Clear the DTCs (Click here).

END

16.REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Replace the millimeter wave radar sensor assembly with a new one (Click here).

Perform millimeter wave radar sensor assembly adjustment (Click here).

NEXT

17.CHECK DTC OUTPUT (RADAR CRUISE2)

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

Enter the following menus: Chassis / Radar Cruise2 / Trouble Codes.

Clear the DTCs (Click here).

Make sure that the DTC detection conditions are met.
HINT:
If the following procedure is not performed, the previously output DTC cannot be detected.
1. Turn the engine switch on (IG).
2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON/OFF).
3. Drive the vehicle at 5 km/h (3 mph) or more for 1 second or more.

Check for DTCs (Click here).
Result
Result
Proceed to
DTC C1A11 is not output
A
DTC C1A11 is output
B

REPLACE DRIVING SUPPORT ECU ASSEMBLY (Click here)

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

18.REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Replace the millimeter wave radar sensor assembly with a new one (Click here).

Perform millimeter wave radar sensor assembly adjustment (Click here).

NEXT

19.CHECK DTC OUTPUT (RADAR CRUISE2)

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

Enter the following menus: Chassis / Radar Cruise2 / Trouble Codes.

Clear the DTCs (Click here).

Make sure that the DTC detection conditions are met.
HINT:
If the following procedure is not performed, the previously output DTC cannot be detected.
1. Turn the engine switch on (IG).
2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON/OFF).
3. Drive the vehicle at 5 km/h (3 mph) or more for 1 second or more.

Check for DTCs (Click here).

Result
Result	Proceed to
DTC C1A14 is not output	A
DTC C1A14 is output	B

REPLACE DRIVING SUPPORT ECU ASSEMBLY (Click here)

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

Result	Proceed to
Bracket is not deformed	A
No. 1 millimeter wave radar sensor bracket is deformed	B
The other bracket than No. 1 millimeter wave radar sensor bracket is deformed	C