How to Troubleshoot the Collision Mitigation Braking System (CMBS)
CMBS Indicator (Amber)
When the CMBS detects a problem during operation, the CMBS stops operating, and the CMBS indicator and the brake system indicator (amber) turns on.

NOTE:
For CMBS function, review the Collision Mitigation Braking System (CMBS) Description.
The CMBS communicates with other control units via F-CAN. For CMBS diagram, refer to the System Diagram for CMBS. If a connected unit malfunctions, the CMBS will not operate. In this case, both CMBS indicator and connected unit indicator come on and stay on (except for the gauge control module).
Self-Diagnostic Function
When a problem is detected by the self-diagnostic function, the CMBS stops operating, turns on the CMBS indicator, indicates the problem on the multi-information display (MID), and stores a DTC.

CMBS OFF Switch
Press and hold the CMBS OFF switch for at least 1 second to turn the CMBS off and on.
CMBS Indication
When the CMBS is OK, the CMBS indicator comes on for a few seconds, then goes off after turning the vehicle to the ON mode.
When you set the CMBS to OFF, the multipurpose camera unit turns on the CMBS indicator.
When the system is activated, the MID indicates a brake system warning indicator and a warning buzzer sounds.
If the system stops operating because of a problem, the MID indicates the problem.
Millimeter Wave Radar
The millimeter wave radar measures the distance between your vehicle and the vehicle directly ahead to calculate the difference in speed between the vehicles.

The millimeter wave radar has a self-diagnostic function. If the system detects a problem, it disables the CMBS, and turns on the CMBS indicator.
Dirt or dust detective function (Clean Millimeter Wave Radar Indication)
If the millimeter wave radar or front grille gets dirty, the CMBS stops operating and the following message on the MID will appear. Clean the millimeter wave radar and the front grille surface.
Once the millimeter wave radar and front grille surface are clean, the message on the MID disappears and the CMBS automatically turns on.

NOTE:
The following MID message may come on temporarily when passing through an enclosed space, such as tunnel.
Under the above conditions DTC P2583-97 is stored.
When it is snowing, the radio waves transmitted and received by the millimeter wave radar may be refracted by the snow or ice attached around the millimeter wave radar such as the front grille. At this time, DTC P2583-76 is stored depending on the situation.
After DTC P2583-76 is stored, the message (Radar Obstructed) is displayed on the MID at the initial stage in some models, and then the indicators come on.
Millimeter Wave Radar Aiming
If the millimeter wave radar is removed or replaced, you must do the millimeter wave radar aiming procedure, otherwise the CMBS indicator blinks.
Multipurpose Camera Unit
The multipurpose camera unit controls the brakes and the various driver warnings when the system recognizes the possibility of a collision.

The multipurpose camera unit also has an error detection function which sends a signal to the millimeter wave radar if an error is detected. The millimeter wave radar receives this information from the multipurpose camera unit.
Dirt or dust detective function (CLEAN FRONT WINDSHIELD Indication)
If the following message appears on the MID, the camera lens or the windshield has enough dirt so that the camera view is obstructed, the CMBS stops operating.

Clean any dirt or contamination on the camera lens or the windshield. Once the camera's view is unobstructed, the indicator on the MID turns off and the CMBS automatically turns back to ON.

NOTE: When millimeter wave radar detected dirt or dust on the multipurpose camera lens or the windshield surface, DTC B2A60-97 is stored as a past failure.

System Protect Function (High temperature) (MULTIPURPOSE CAMERA HOT Indication)
If the following message appears on the MID, the CMBS stops operating, and stores a DTC.

When the multipurpose camera temperature cools down to its proper operating temperature, the indicator on the MID turns off, and the CMBS automatically resumes operation.

Multipurpose Camera Aiming Function
If the multipurpose camera unit is removed or replaced, you must do the multipurpose camera aiming procedure. If the aiming is incomplete, the CMBS indicator blinks.
CAN Communication
The CMBS communicates with other control units via F-CAN. For CMBS diagram, refer to the System Diagram for CMBS.

If the millimeter wave radar and the multipurpose camera unit detects a communication error or a malfunction in another connected unit, the CMBS system will not operate even though it is OK. In this case, both the CMBS indicator and the related unit indicator will come on and stay on.
How to Troubleshoot DTCs
Check the DTCs with the HDS.

NOTE: For CMBS DTCs, refer to the DTC troubleshooting index.

Before troubleshooting, check and note these items:
Ask the customer about the conditions when the problem occurred, and try to reproduce the same conditions for troubleshooting.
If the symptom does not appear and the CMBS indicator does not come on while test-driving, but troubleshooting is done based on the DTC, check for poor connections or loose terminals at all connectors related to the circuit that you are troubleshooting.
After the troubleshooting or repairs are done, clear the DTCs, and test-drive the vehicle under the same conditions as when the DTC was originally set. Make sure the CMBS indicator does not come on.
The CMBS may sometimes stop control because of the environment (weather, road conditions, driving conditions, etc.). Intermittent failure DTCs may be stored in these cases.
Intermittent Failures
The term ''intermittent failure'' means a system may have had a failure, but it checks OK now. If you cannot reproduce the condition, check for intermittent failure DTCs. If intermittent failure DTCs are not stored, check for loose connections and terminals. Also check ground and power connections related to the circuit that you are troubleshooting.
How to Retrieve DTCs
NOTE: Make sure the 12 volt battery is fully charged before you begin.

1.

2.
Use the HDS to check for Integrated Driver Support System DTCs.

3.
Read and record the DTC.

4.
Turn the vehicle to the OFF (LOCK) mode.

5.
Disconnect the HDS.

6.
Do the troubleshooting procedure for the DTC.
How to Clear DTCs
NOTE: Make sure the 12 volt battery is fully charged before you begin.

1.

2.
In the Driving Support of the HDS, select Integrated Driver Support System, then DTCs, choose the clear DTCs icon, and follow the prompts.

3.
Turn the vehicle to the OFF (LOCK) mode.

4.
Disconnect the HDS.