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Discussion Starter · #1 ·
I know that upper and lower mesh grilles on an XLR result in the loss of cruise control, but now I'm being told it also impacts the air flow causing the computer to throw codes, usually resulting in the Service Engine Soon light randomly coming on... has anyone else seen this? My mechanic says there was a GM bulletin describing all the problems caused by this upgrade, but has not found it to show me. Other than the cruise control, I had not heard of any other problems. I bought my car with the grille already installed so I'm at a loss at this point.
 

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I've had my '06 since February of '08 and it also had the mesh grill installed when I purchased it (upper only). I have driven around 10,000 miles since then and have not encountered any problems caused by the grill. I'm in PA so we should see similar weather conditions.

Jon
 

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Discussion Starter · #5 ·
Thanks for the replies. I was suspect due to the fact the Service message comes on when I start the car, not when its moving. They say there is a GM bulletin, which I've yet to see that warns about the cruise control and the air flow problem. They wanted to replace my grille with the original, but I bought the car with the mesh installed. They are supposedly modifying my grille with parts from an old original grille to deflect air flow to the mass air sensor. We'll see... I'll keep you posted and also try and get the GM bulletin info. Thanks again.
 

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The upper grill, as stated above, has nothing to do with cooling. For cars equipped with adaptive (radar controlled) cruise control, the mesh may interfere with the radar emitter. The cooling opening is the lower grill. (Notice the front of the Corvette. Same deal.
Jester:jester
08 White
 

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Discussion Starter · #7 ·
Here's the analysis from the GM Tech. After reviewing the engine data, the code is being set around 40mph. Based on the GM bulletin about lower grille changes, he said "the issue is that normally behind the side lenses there is no air intake. The center piece allows air through and there are some deflectors that channel the air in and up through the radiator. Those deflectors are gone causing incoming air pressure to go around the radiator shroud and up to the air intakes causing this error in MAF calculation."

That seems to be the ground Cadillac is sticking to, the suggested fix is to replace the lower grille and associated parts per original specs. Having bought the car after the changes were made means ordering the parts for replacement. I'll let you know how the story goes, of course there is no guarantee this will fix the issue, but all other options have been pursued. :skep
 

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I have been following your thread on this topic and would suggest you contact D3 performance www.d3cadillac.com and see what they recommend.

The reason is that they have considerable experience with the mapping and remapping process on both the XLR and the XLR-V with a variety of performance enhancements.

MAF sensor failures due to the grill lower being installed are not a normal conclusion.

Also please read the posting on this topic here. To be sure you see all of them please be sure that the settings at the lower portion of the page are set to "The Begining"

Please keep us informed of the progress.

Regards



 

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Discussion Starter · #9 ·
LATEST UPDATE:
:cry
After waiting two weeks for diagnosis and parts, the lower grille was removed and replaced with a stock grille and the supporting sir deflectors that funnel airflow up past the radiator towards to air intakes. A day after getting the car back the "Service Vehicle Soon" message returned in the DIC and the car was returned to the dealership for attempt #7 to repair...

To recap : 1) new throttle body 2) gas cap and mass air sensor 3) reload updated programming into ECM 4) another new throttle body (supposedly new model) 5) new air intake manifold gaskets and tighten loosened bolts 6) remove aftermarket mesh lower grille and restore original parts due to GM bulletin
:mad
Car runs fine, but manual indicates this message indicates engine problem and should be taken to dealer immediately. My concern is the "boy that cried wolf syndrome", someday this message may indicate real problem! Right now it gives the typical air flow codes associated with mass air/throttle body problems and sets at a speed of 40mph, message appears the next time I start up the car.

I've suggested a new computer, maybe there's a problem there. Cadillac insists that cannot be the problem. :banghead

Thank God for warranty, although the last change was out of pocket because they blamed the aftermarket product, though apparently unfounded. :nopity
 
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