How to Troubleshoot the Adaptive Cruise Control (ACC)
ACC Indicator (Amber)
When the ACC system detects a problem while operating, the ACC system stops working, then the ACC indicator and the brake system indicator (amber) stay on.

NOTE:
For ACC function, review the Adaptive Cruise Control (ACC) Description.
The ACC system communicates with other control units via F-CAN. For ACC system diagram, review the ACC System Diagram. If a connected unit malfunctions, the ACC system will not operate. In this case, both ACC indicator and connected unit indicator come on and stay on (except for the gauge control module).
Multi-Information Display (MID) Indication
When the ACC system is OK, the ACC indicates its status on the multi-information display (MID) when the MAIN switch is ON.

Self-Diagnostic Function
The ACC system has a self-diagnostic function. If the self-diagnostic function detects a malfunction, the ACC system stops operating. The ACC indicator comes on, and the ACC system indicates "Adaptive Cruise Control Problem" on the MID.

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 ACC, and turns on the ACC indicator.
Dirt or dust detective function (Clean Millimeter Wave Radar Indication)
If the millimeter wave radar or front grille gets dirty, the ACC system 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 ACC system 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 ACC indicator blinks.
Multipurpose Camera Unit
The multipurpose camera unit uses inputs from the millimeter wave radar to maintain a constant distance between your vehicle and the vehicle directly ahead by accelerating and braking as needed.

The multipurpose camera unit also has an error detection function which sends a signal to the millimeter wave radar if an error is detected.
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 ACC indicator blinks.
CAN Communication
The ACC system communicates with other control units via F-CAN. For ACC system diagram, review the ACC System Diagram.

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

NOTE: For ACC system 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 ACC indicator does not come on while test-driving, but if your troubleshooting was based on a 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 ACC indicator does not come on.
The ACC system sometimes stops operating because of certain environmental conditions (weather, road conditions, driving conditions, etc.). Intermittent failure DTCs or ACC System Auto Stop Control Codes may be stored in these cases.
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.