Adaptive Cruise Control (ACC) Symptom Troubleshooting - Intermittently senses the vehicle driving ahead
Intermittently senses the vehicle driving ahead
- Road condition check
-1. Find out if the detection problem occurs only on a particular road such as a winding road, an entrance of a corner, an exit of a corner, a tight corner, or a bad road.
Does it occur only on a particular road?
YES
Explain to the customer that the system sometimes cannot detect under certain road conditions.
NO
Go to step 2.
- Weather condition check
-1. Find out if the detection problem occurs only under poor weather conditions such as fog, snow, heavy rain, or gusty winds.
Does it occur only under poor weather conditions?
YES
Explain to the customer that the system sometimes cannot detect under poor weather conditions.
NO
Go to step 3.
- Driving condition check:
Find out if the detection problem occurs only when the vehicle ahead drives under these conditions:
- Merged into the lane suddenly.
- Closing on a vehicle within 4 m (13 ft).
Does it occur only under certain driving conditions?
YES
Explain to the customer that the system sometimes cannot detect under certain driving conditions.
NO
Go to step 4.
- Millimeter wave radar aiming check
-1. Confirm if the radar detects vehicles driving in another lane.
Does it detect vehicles in other lanes?
YES
The millimeter wave radar horizontal aiming is incorrect. Aim the millimeter wave radar aiming .
NO
Go to step 5.
- All condition check
-1. Find out if the detection problem occurs under all conditions.
Does it occur under all conditions?
YES
The millimeter wave radar vertical aiming is incorrect. Aim the millimeter wave radar aiming .
NO
Go to step 6.
- Other component check
-1. Confirm if the detection problem is caused by instability.
NOTE: If the cause of the misdetection or undetectable problems is unclear, it is possible that the problem was caused by environmental conditions. Explain to the customer that intermittent failures are sometimes caused by environmental conditions.
Is the vehicle unstable? (Compare it to a known-good, like vehicle.)
YES
Check other components such as VSA modulator-control unit or wheel speed sensors, etc.
NO
Go to step 7.
- Heavy load check
-1. Check if there is a heavy load on the vehicle.
Was there a heavy load on the vehicle?
YES
Remove the heavy load from the vehicle. Advise the customer that this problem may occur temporarily when hauling heavy loads.
NO
Go to step 8.
- Millimeter wave radar and front grille check
-1. Check for dirt, dust, or snow on the surface of the millimeter wave radar and the front grille.
Are the millimeter wave radar and front grille OK?
YES
Go to step 9.
NO
Clean the millimeter wave radar and the front grille.
- Vehicle's history check
-1. Check the vehicle's history for front end collision repairs.
Has the vehicle been in a collision and repaired?
YES
Go to step 10.
NO
Go to step 12.
- Millimeter wave radar installing check
-1. Check if the millimeter wave radar and its bracket are installed correctly, and also check if the vehicle frame is straight.
Are all parts installed correctly?
YES
Go to step 11.
NO
Reinstall the part correctly, or if damaged, replace the part, then aim the millimeter wave radar .
- Vehicle ride height check
-1. Measure the front and rear vehicle ride height.
Is the vehicle ride height equal?
YES
Go to step 12.
NO
Inspect the suspension for damage, and compare ride height to a known-good vehicle. Adjust the wheel alignment as needed .
- Wheel alignment check
-1. Check the wheel alignment .
Is the wheel alignment OK?
YES
Aim the millimeter wave radar .
NO