I would like to fab up a 'shield' or something that would prevent my 'smart cruise control' from 'looking at the other lanes'. My system will detect cars and trucks in both lanes and react to all. I want to make a 'shield' that would only allow the sensor to 'see' forward and not to either side. Has this been done in the past?

You don't want to go there . . . for a lot of reasons.

The ACC self-calibrates by checking out all the obstacles on either side of the road. The more stationary objects, (sign posts, cement barriers, etc) the better the calibration. Unless you know a lot about antenna theory and exactly how this system works, placing RF shielding around the transmitters and receivers to adjust the beam lobes is asking for trouble by modifying a system that automatically activates your brakes and speed control. There's a good reason why the system "looks" at the other lanes. . . A low doppler shift would be normal for vehicles moving near the same speed. A super-high doppler shift would be indicative of a vehicle moving head-on toward you, so I would assume the software rejects that on a two-lane road.

Now that I think about it, I've never even used it on a two-lane road, only for highway driving where all adjacent lanes are moving in the same (doppler-wise) direction. Has anyone else used ACC much on straight or twisty two-lane (bi-directional) roads with oncoming traffic? Does the system flip out and display the red CRASH icon with oncoming vehicles?

CC :seeya

You don't want to go there . . . for a lot of reasons.

The ACC self-calibrates by checking out all the obstacles on either side of the road. The more stationary objects, (sign posts, cement barriers, etc) the better the calibration. Unless you know a lot about antenna theory and exactly how this system works, placing RF shielding around the transmitters and receivers to adjust the beam lobes is asking for trouble by modifying a system that automatically activates your brakes and speed control. There's a good reason why the system "looks" at the other lanes. . . A low doppler shift would be normal for vehicles moving near the same speed. A super-high doppler shift would be indicative of a vehicle moving head-on toward you, so I would assume the software rejects that on a two-lane road.

Now that I think about it, I've never even used it on a two-lane road, only for highway driving where all adjacent lanes are moving in the same (doppler-wise) direction. Has anyone else used ACC much on straight or twisty two-lane (bi-directional) roads with oncoming traffic? Does the system flip out and display the red CRASH icon with oncoming vehicles?

CC :seeya
I have used mine on two lanes quite a bit here in Montana with no problems with oncoming traffic or curves. It works stupendously (hopefully that's actually a word??).

AzGeo:

I agree with CC and Rod.

I have used it many times and never had it over react to cars coming the other way. I would suggest a trip to the dealer to see if it is aligned properly and has the right software.

As you posted it is not a good idea to mess with this feature for all of the reasons you mentioned.!!!

Perhaps the bracket has a break, causing the eye to be off-center? The bracket is aluminum and doesn't look to be particularly strong.

Rod is right. If the bracket is out of alignment, self-calibration may not work.

The dealer has a tool to do the job, alignment tool (J45442.)

I submit a little Adaptive Cruise Control 101 for those who are interested or are having trouble sleeping:

The Adaptive Cruise Control (ACC) system's controller is the Distance Sensing Cruise Control (DSCC) Module. --There's one available on eBay as I write.

The ACC system allows the vehicle to operate at or below the driver-selected set speed --depending on traffic conditions. The system uses radar to detect objects in the vehicles' path and then slows the XLR depending on the object's range and closure rate; --doppler for you fellow geeks like me out there.

The DSCC module consists of a forward-looking radar sensor and the DSCC controller. The radar is used to detect and classify objects in the road ahead of the vehicle. If the radar detects objects within its field of view, the DSCC controller issues throttle and/or brake commands via the GMLAN (high speed/priority) bus to the Engine Control Module (ECM) and Electronic Brake Control Module (EBCM) to control XLR's speed and keep you, --a valued customer out of the obituaries, and contributing to our fine forum here.

The DSCC module is a Delphi product and uses 76Ghz radar pulses. It's located behind the front fascia on the driver's side. The module mounts to a bracket that attaches to the left side frame rail near the bumper beam. When activated, it radiates through the plastic lens of the front fascia. --Plastic being the operative word here, is nearly transparent to radar beams. If you want the look of the V's lower metal mesh grill, you will most likely sacrifice your ACC option.

I've droned on long enough. Test on Monday.

CC :seeya

If I'm in the #1 lane going 75 MPH and I start to pass a truck in the #2 lane going 60 MPH, (same direction) my car will SLOW to follow the truck rather than SEE the open road ahead of me in my lane. Alignment or actual problem?

Your problem could be either or both. With the system operating normally you shouldn't have any problems passing a car in an adjacent lane that's going slower with ACC enabled. I'd take it in and have it checked out.

Is this an issue that just started, or has it always behaved this way since you bought the car? When operating correctly, it's a really nice enhancement --especially on long freeway drives.

Once fixed, let us know how it was resolved, okay?

CC

AzGeo, one thing you did not mention is the type of traffic you are encountering. If you are in heavy, metro traffic the ACC can be very frustating and I usually turn it off in these conditions. It works well, as others have stated, on rural interstates with moderate traffic. You also need to be aware of the 'car ahead' indicator (a small car appears in the HUD) and the the following distance adjustment on the steering wheel. You will notice that your car starts to slow down to match the speed of the car ahead of you shortly after the 'car ahead' appears; and you can adjust how soon this happens with the distance adjustment.

Also, you need to be fully in the passing lane for the ACC to recognize that car you are passing is clear of your path. I notice that it does not always acceterate in the same way that I would since it cannot 'guess' when you are going to move into the passing lane.

Since you joined this forum recently, I'm assuming you are a new owner. If so, it does take a little expirmentation with the ACC to fully appreciate its operation.

Hope this helps. Jon

CC is on to something with the bracket being out of alignment. If you can't get behind a vehicle with the ACC on and pull out into a clear lane and have it accelerate to the speed you set then its out of alignment for some reason.....bracket bent, broken or......

CC Now FOR YOUR HOMEWORK......We need find a way to use the ACC system technology to enhance our existing radar detectors.........

"Kahuna" While on hiway #40 (open road) divided roadways and at posted 75 MPH speeds. Large spaces between packs of cars/trucks. This system has always worked this way. It does work correctly when following at my 'set personal interval', but when passing a slower vehicle (slower on right) and no vehicle directly ahead of me, it freaks out. Thank you all for your insite and tips, I will first address 'alignment' and then ???

Sorry Jerry, but I can’t take one iota of credit for the bracket misalignment theory; that honor goes to Rod.

As for my homework, it’s done. Here it is:

Police radars (in the US) work on the following frequencies:

10.50 to 10.55 Ghz (X band)
24.05 to 24.25 Ghz (K band)
33.40 to 36.00 Ghz (Ka band)
Everything else (Walmart doors)

The XLR’s radar transmits and receives at 76 Ghz, far above the police bands. This was designed intentionally, to avoid interference, --the same as the Easy Key (fob) system. You wouldn't want some intra-cranial, blinking bluetooth headset-wearing Borg wannabe walking by your car as they're yacking away and have your doors unlock or trunk open, right?

Generally speaking, the best location for a threat/warning receiver is as high as possible. Even if the XLR’s forward-looking receivers could be tuned to do this, their position is less than ideal, and of minimal use for rearward threats.

The best idea I’ve seen in awhile is the integrated V1 and HUD display currently under development for the Corvette HUD. I spoke with a couple of guys at work and it doesn’t sound too difficult to build. For starters, the handshaking between the V1 and it’s remote would need to be mapped out on a protocol analyzer, then the same would need to be done on the Class II bus between the Device Logic Controller and HUD. An interface would need to be built to transmit the V1’s output into ASCII characters with position information on the HUD. We have the talent and equipment to do it, but all of us are tied up with bigger fish to fry and I have an impending move from WA to Sacramento as soon as my place sells. I’m pretty much slammed for the next six to eight months. But who knows? If nobody builds one for us, and the need is still there to justify the time and expense, I’ll consider it down the road. Like most of you I’m sure, I’ve got multiple irons in the fire, and time is the one luxury I never seem to have enough of.

Back on Thread:

Here’s a little ACC 105 for those of you who can’t get enough of the XLR Xperience or refuse to be lulled to sleep with ab-buster ads tonight:

If any cruise control components fail or engagement requirements (clean sensors, gap distance, really tight curves) are not met, the system will not operate. Additionally, the radar must be mechanically aligned for the system to work as advertised.

RADAR NOT READY: Causes can include overheated brakes, an over temp in the radar transceiver in the DSCC module, system voltage out of specs, or the radar is not detecting an object during the current ignition cycle.

More on Alignment: The ACC system has a continuous alignment function during vehicle operation with ACC engaged. How far the vehicle needs to be driven to achieve proper alignment depends on the number of detected stationary objects on the side of the road. More detects will achieve faster alignment. The Tech II scan tool is equipped to display the ACC automatic alignment status as well as DSCC module alignment error (skew or yaw --if you’re flight-trained.) Skew in excess of 3.9 degrees will set an error code. In this case, the dealer’s mechanical alignment tool comes into play.

Something to remember: The system needs to recalibrate itself after a wheel alignment.

Stay tuned as we delve into the mysteries of the Heated and Cooled Seats!

CC :cheers

CC:

Thanks. WOW thats more information than I was able to turn up on the valentine site about thier radar.

You definitely have a lot of technical information stored in your head.

Are you afraid its going to explode if you get too near some of the new electronics??