Return to Service - An ADAS Case Study
I'm sharing a recent experience here that I think some might find interesting. A couple of weeks ago one of my technicians and I travelled to North Carolina to attend the Mobile Tech 2-day ADAS training event advertised here:
It was recommended that attendees renting vehicles should try and secure a vehicle with ADAS. We arrived Friday the 26th of April in Charlotte and had about a 3+ hour drive to Wilmington. While walking the parking lot of National, we came across a vehicle equipped with Nissan's ProPILOT Assist which appeared to be a good candidate.
After departing the airport we headed for the highway and this is where we encountered our first anomaly. With every advanced feature on, we engaged the ICC (Intelligent Cruise Control) with intelligent lane intervention system and the vehicle locked on to the vehicle ahead and the lane markings. Now, although the system states that it can handle moderate sweeping turns, the first one we came across challenged the vehicle which failed to stay in the lane! A little later we reengaged the system and it did pretty well in moderate to stop and go traffic. Then while in stop and go traffic, the speed picked up to about 40-50 where we were all moving along nicely. Then about 2 minutes later traffic ahead began to stop but my vehicle wasn't planning on it which required driver intervention. This was very odd because my trust factor has increased due to its past performance. At this point I thought, wow, how could this vehicle miss all that.
Approximately 10 minutes later while in open traffic and ICC engaged, a warning light came on along with the following message letting us know that ICC was no longer available: (disregard the mileages recorded in these images, these were captured later after learning more about the failure modes)
We pulled over and performed a visual to see if we could detect anything amiss which we came up negative. After a key cycle, the system re-enabled and allowed us to re-engage the system. A short while later (10-12 min.) the same message appeared and the following status was shown each time you attempted to engage the ICC.
The next day at class, I informed the instructor that we had real live problem in our hands and that I would like to learn more about this vehicle. He proceeded to have one of his technicians perform a query using the Nissan Consult-III and then printed all the factory service information we would likely need to analyze and diagnose the vehicle. (I assume that his technician looked at this and had it figured out fairly quickly.)
The following DTC was the only one stored: C1A16-97 RADAR STAIN [CMP/SYS OPR OBST OR BLKD]
After performing a visual inspection we found that the front facing radar was not pointing straight ahead level with the ground:
(All of us working through this issue came to the consensus that this vehicle had recently had some collision work performed on the front end.)
This is the normal position of the radar sensor:
For the class, we temporarily bent the bracket forward and performed the sensor calibation:
Following that, four of us went for a test drive and recorded the following data:
Near the end of the second day, we decided to return the bracket back to its original orientation and logged more data:
Further, we road tested the vehicle and made several observations. The following two pictures show how the radar sensor is able to pick up a higher profile vehicle over a lower one with a bent bracket.
In closing, I'd like reflect on the "Return to Service" found in my subject like which makes reference to the FAA:
14 CFR § 43.5 - Approval for return to service after maintenance, preventive maintenance, rebuilding, or alteration.
How are we as an industry validating that the vehicles you service with ADAS are approved to be returned to service? We're all aware of the pre-post scan position statements, however, If this vehicle was followed up with a post scan, it likely passed as long as the vehicle wasn't taken on an extended road test. I'm interested in hearing your thoughts on this.
Ps, I had a conversation with the manager at the National Car Rental @ CLT about the vehicle and how it appeared that there had been some recent collision repair which likely resulted in the bent bracket. While I was on the phone with them, they reviewed the vehicle service history and stated that the only logged entry was one oil change in 6k miles. I returned the vehicle to the center and was assured that it would not be placed back into service until the issue I reported had been properly repaired. They also refunded my rental charge.
Hi Scott: Nice …e study. Mind if I borrow it for show-n-tell? No class involved but I'll give attribution. The manager would be a fool to place this unit back in service, especially if he knows that you documented it. He's an even bigger fool if he used Fly By Night Collision Repair and has no documentation. Bent brackets are a common failure. My perspiration level (sitting next to a judge…
Hi Scott, I'm putting together a short basic ADAS on the horizon type article for 'The Automotive Technician' (TAT) magazine in Australia/New Zealand. Would you be open to me using your bent radar bracket photo and referencing it to diag.net Thanks for your consideration
Sure Brendan and thanks for asking. A reference/credit would be honorable.
Did you bend that bracket to get a free rental again?😂 Nice case study!
Thanks Scott, I‘m still stuck on the “radar stain” code. What a revealing case study
Great work Scott. You guys really had a good example of a very real and ongoing issue, especially when dealing with rental fleets. Its astonishing when you account the liability aspect that National takes on when these vehicles are repaired and not properly vetted for use. I wish I could say this is a rare occurrence with, but as more and more studies and data acquired post repairs, we are…
Sir am in ghana west Africa and I to hv the opportunity to learn fully on this adas systems,kindly assist me if u get to know of any forum education on adas am ready to learn. its rare in my country
from what I have learned, the radar stain code is common when they are physically out of alignment. I have only seen that code on Nissan. The only way to validate the alignment/calibration is a test drive, with the vehicle braking and stopping. Such as at a red light, in traffic. It must be an extended test drive. Sometimes 20-30 miles. I will take an Audi or VW with the twin distance sensors…
A year ago I had a issue like this on a Acura MDX... had a code for radar blocked detected . I never figured it out .. I didn’t have the tools and wasn’t to knowledgeable on this subject .. I did know the radar was ok due power and ground and communication lines being good ,,they took it to the dealer and the dealer sold a new radar told them about the after market grill they didn’t replace it…
Scott, I really like that you found a real world problem. It is a concern that you found a faulty vehicle so easily. How many other vehicles are running around with issues like this? The fact that a key cycle would reset a defective system is also concerning. Great write up!
It was great seeing you at this event and kudos to David and Issac for hosting it! What luck that an ADAS equipped rental has an issue on its way to an ADAS event! Unfortunately this doesn't seem to be too uncommon. I have seen a few of these with nearly identical issues. "Radar blocked" or "radar stained" is the standard code that sets when these fail. I would like to think that as these…
Interesting. And dangerous. You'd think they'd have some type of level sensor in it to ensure it is in the proper position.
The level sensor may be a good idea but will require more programming to function normally. What if it’s driving uphill? Parked on a sloped driveway? The repairs meed to be performed properly. As an industry there are many corners cut that should not. Education and legislation is key, but how do we, as an industry, ensure compliance?
Chris, These systems have limitations. They will not pick up vehicles ifo when coming out of a turn, cresting or descending a hill, or immediately thereafter. Level sensor is not practical or necessary. They will gather misalignment angles as they drive. This will determine vertical and horizontal alignment, or level. If they are grossly misaligned, they will cease operation and illuminate the…
They do have a level sensor. It's located in the airbag module ;) The "technology" in these systems does not exist in the components but rather in the software.
That's cool. I had a 2017 Tahoe recently with left side blind zone alert inop. I test drove , right side worked fine, but sure enough left side nothing. Sometimes when pulling away from a stop the left exterior mirror indicator would flash but that was all. Full module scan nothing. Decided to do a visual inspection. And the left side detection module bracket had come loose from the inside of…
What a lucky/unlucky find for rental car for this kind of training. As Carm would say - learn just one thing - even not attending this training event (me being in Australia) I've added a few more pieces to my newly started ADAS knowledge puzzle.
For anyone interested in knowing a little more about this issue, I received word from Nissan that they looked into the history on this vehicle and they claim that the build images were clean on this vehicle and after visiting with Enterprise (National Parent) they claim to not have any history of collision damage/repair so the condition I found the vehicle in remains a mystery. For those…