Road Sign Assist System Precaution

Under the following conditions, signs may not be displayed or the system may not operate.

1. Misalignment has occurred in the installation of the forward recognition camera
   
2. Mud, snow, ice, a sticker, etc. is stuck to the windshield in the forward recognition camera's field of view
   
3. During poor weather, such as heavy rain, heavy snow or dense fog
   
4. A bright light source is shining in front of the forward recognition camera
   
5. The sign is dirty, faded, angled, bent or has poor contrast (if electronic)
   
6. A part of the sign is concealed
   
7. After the forward recognition camera acquires the sign, the vehicle passes by too quickly
   
8. The driving scene is misjudged
   

Under the following conditions, the incorrect sign may be displayed or the system may not operate properly.

1. Speed limit signs on side roads may be detected and displayed (if positioned in the detection range of the front sensor) while traveling on a main road
   
2. Speed limit signs on roundabout exit roads may be detected and displayed (if positioned in the detection range of the front sensor) while traveling on a roundabout
   
3. The speed information displayed on the meter may differ from the speed information displayed on the navigation system (if equipped) due to the navigation system using map data
   
4. A sticker applied to the rear of the preceding vehicle is recognized as a sign
   
5. A shape resembling a supported sign is recognized
   
6. Immediately after moving over to a state or country with different speed limit units or driving directions
   
7. The driving scene is misjudged
   

If the malfunction is due to connectors being loosely connected, or improper installation of parts, reconnecting the connectors or removing and reinstalling the parts may temporarily or completely correct the problem.

The road sign assist system may be affected by malfunctions in other systems. Check for DTCs in other systems and, if present, troubleshoot those DTCs first.

If the forward recognition camera has been replaced with a new one or the windshield glass has been removed and installed, it is necessary to perform Recognition Camera/Target Position Memory and Recognition Camera Axis Adjust (Click here). If the system is turned on without performing Recognition Camera/Target Position Memory and Recognition Camera Axis Adjust, DTC C1AA9 will be stored.

When replacing the forward recognition camera, 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 and a DTC may be stored.

When replacing or removing/installing the forward recognition camera, do not damage the camera lens or allow it to become contaminated with foreign matter.

Do not reuse a forward recognition camera that has been dropped or subjected to a strong impact.

When replacing the windshield glass of a vehicle equipped with a forward recognition camera, make sure to use a Toyota genuine part. If a non-Toyota genuine part is used, the forward recognition camera may not be able to be installed due to a missing bracket or the road sign assist system may not operate properly due to a difference in the transmissivity or black ceramic border.

Do not attach stickers, including transparent stickers, or other items to the outer side of the windshield glass assembly within the area in front of the forward recognition camera.