XLR Service Bulletin Details

[MrO]

Hi Guys,

Still going thru idle issues with the 2004 XLR. To re-summarize: sometimes the idle is rough and will bounce between 800rpm and 1100rpm will no response from the gas pedal. Had it at the dealer for 2 days and they couldn't figure it out. The said they've never seen so many error codes read out on their tester. They wanted to just start replacing modules until the problem went away... Sometimes it idles and drives fine. Other times it does the idle pulse with NO effect from the gas pedal. The unpredictability of this evil spirit makes it impossible to trust on any trip distance.. Anyway... I found these two service bulletins that sound familiar:

2004 Cadillac XLR Service Bulletins
75 TSB No.: 040604013 NHTSA No.: 10008668 TSB Date: March 1, 2004 Date Added to File: August 13, 2004
Failing Component: Engine And Engine Cooling:Engine
Summary: Lack of power, check engine light, traction control light on, diagnostic trouble code (dtc) P2108 set.

134 TSB No.: 102403 NHTSA No.: 10005011 TSB Date: October 24, 2003 Date Added to File: January 26, 2004
Failing Component: Electrical System
Summary: Complaints that the vehicle has reduced power and will not go over five miles an hour and the traction control message is displayed on the dic. Gm voicemail log

Any ideas on how to find out what the recommended fixes were for these problems??

Thx!

 

[ccclarke]

If GM has a list of historical fixes for this issue, your dealership's Service Department should have the resources to obtain the information. If they want to go the "Easter Egging" route for troubleshooting, that wouldn't inspire confidence in me. You're essentially paying for their training to learn how to troubleshoot your vehicle. Do they have a certified XLR tech on site? If not, look for another dealer.

CC

 

[HOMEGAMEROOM]

An intermittent rough idle might indicate that one (or more) of your ignition coils is failing. They can operate sporadically, and they don't last forever. They also don't necessarily set a DTC unless they are inpoerable for a longer period of time (the eventual DTC would be a misfire on cylinder X).

XLR's always have at least one or 2 DTCs set in them. I can't recall what the "standard" ones are, but, as long as everythng is running well, don't worry about it.

Also, be SURE your battery is fresh! 04's tend to drain them and that can set all kinds of codes (there are MANY threads on that issue).

Good luck - let us know what the result(s) is!

 

[MrO]

Certified XLR tech? Absolutely. Thx to this forum that was the first question that I asked before I let them look at the car... But... Not to impressed with their technical expertise.

 

[MrO]

An intermittent rough idle might indicate that one (or more) of your ignition coils is failing. They can operate sporadically, and they don't last forever. They also don't necessarily set a DTC unless they are inpoerable for a longer period of time (the eventual DTC would be a misfire on cylinder X).

XLR's always have at least one or 2 DTCs set in them. I can't recall what the "standard" ones are, but, as long as everythng is running well, don't worry about it.

Also, be SURE your battery is fresh! 04's tend to drain them and that can set all kinds of codes (there are MANY threads on that issue).

Good luck - let us know what the result(s) is!

Yup, new battery... Same problem... Interesting suggestion on the ignition coils... Couldn't hurt to look into that... Don't understand why that would cause the lack of response from the gas pedal though.... I'm starting to lean toward something in the main computer that governs all the ignition controls though... Temped to just swap it out... But... That's an expensive "guess" since most auto electrical parts are non-returnable....

 

[BusaMan]

Just an obtuse thought: give it a once over for vacuum leak(s). Strange things can happen w/ those, including sensors generating unexpected states. I'd also look hard at the intake plumbing for leaks. FWIW - can't hurt.

Tim

(I have a tendency to look for cheap stuff first. )

 

[HOMEGAMEROOM]

A new battery is great. I ALWAYS keep mine on a Battery Tender when I'm at home to insure the charge stays as good as possible. Knock on wood, I've had no strange error messages since I've started doing that.

If you have a rough idle, you can take the cover off of the engine and, one by one, unplug the ignition coils. If there is a change when unplugged (as in it runs worse), the coil is fine. If there is NO CHANGE, you might have discovered a bad coil. Of course, bad wiring further down the line would look the same as a bad coil, but that's pretty rare.

I bought a new coil bank on Amazon for about $130.00. Be aware that a new coil bank's coils are NOT interchangeable with the coils on an original 2004 NorthStar engine, though the new bank will fit perfectly.

And looking for a vacuum leak is a good idea too!

 

[MrO]

A new battery is great. I ALWAYS keep mine on a Battery Tender when I'm at home to insure the charge stays as good as possible. Knock on wood, I've had no strange error messages since I've started doing that.

If you have a rough idle, you can take the cover off of the engine and, one by one, unplug the ignition coils. If there is a change when unplugged (as in it runs worse), the coil is fine. If there is NO CHANGE, you might have discovered a bad coil. Of course, bad wiring further down the line would look the same as a bad coil, but that's pretty rare.

I bought a new coil bank on Amazon for about $130.00. Be aware that a new coil bank's coils are NOT interchangeable with the coils on an original 2004 NorthStar engine, though the new bank will fit perfectly.

And looking for a vacuum leak is a good idea too!

All valid points and next on my to-do list. Thx for the conventional wisdom! I'm leaning toward vacuum though. Your post reminded me that one of the issues with the 2004 XLR was intake manifold bolts that were proned to loosening... Time to get out the 'ol torque wrench. If any of y'all could share the tightening order, it would be great!! Otherwise I'll google it....
Cheers

 

[Stella]

All valid points and next on my to-do list. Thx for the conventional wisdom! I'm leaning toward vacuum though. Your post reminded me that one of the issues with the 2004 XLR was intake manifold bolts that were proned to loosening... Time to get out the 'ol torque wrench. If any of y'all could share the tightening order, it would be great!! Otherwise I'll google it....
Cheers

Sorry to hear your problems with your car. Question what do you mean no response from the gas pedal? I know a good way to check for any vacuum leaks is to have the engine running. Then take a can of starting fluid even brake clean works and spray around the thought to be problem area. The vacuum will pull in the fuel and the rpms will rise. Works great hope it'll help.

 

[MrO]

Sorry to hear your problems with your car. Question what do you mean no response from the gas pedal? I know a good way to check for any vacuum leaks is to have the engine running. Then take a can of starting fluid even brake clean works and spray around the thought to be problem area. The vacuum will pull in the fuel and the rpms will rise. Works great hope it'll help.

No response=no change in idle when you pump the gas pedal...VERY frustrating!! Good point on the vacuum check. I had forgotten about that trick... I'll give that a try first....

 

[HOMEGAMEROOM]

Propane works well for that too, if you have a tank handy.

 

[MrO]

Propane works well for that too, if you have a tank handy.

You read my mind...

 

[MarkSki]

I bought a new coil bank on Amazon for about $130.00. Be aware that a new coil bank's coils are NOT interchangeable with the coils on an original 2004 NorthStar engine, though the new bank will fit perfectly.

Are there different 2004 NorthStar Engines? One for the XLR and one for the other cars that use the NorthStar engine?

 

[HOMEGAMEROOM]

I'm not 100% sure.... The bottom line is that all of the NorthStar family share many common parts for whatever version they are in. (the coil bank is shared by other N*'s)
The XLR has a slightly unique engine, since it's the only version of the N* that is mounted the "normal" way (not transverse), but that affects the mounting components more than anything else.

 

[Rob]

Also, click on the Knowledgebase in the navigation bar above. We may have a copy of those Service Bulletins in there.

-Rob

 

[xlrlist01]

Hi Guys,

Still going thru idle issues with the 2004 XLR. To re-summarize: sometimes the idle is rough and will bounce between 800rpm and 1100rpm will no response from the gas pedal. Had it at the dealer for 2 days and they couldn't figure it out. The said they've never seen so many error codes read out on their tester. They wanted to just start replacing modules until the problem went away... Sometimes it idles and drives fine. Other times it does the idle pulse with NO effect from the gas pedal. The unpredictability of this evil spirit makes it impossible to trust on any trip distance.. Anyway... I found these two service bulletins that sound familiar:

2004 Cadillac XLR Service Bulletins
75 TSB No.: 040604013 NHTSA No.: 10008668 TSB Date: March 1, 2004 Date Added to File: August 13, 2004
Failing Component: Engine And Engine Cooling:Engine
Summary: Lack of power, check engine light, traction control light on, diagnostic trouble code (dtc) P2108 set.

134 TSB No.: 102403 NHTSA No.: 10005011 TSB Date: October 24, 2003 Date Added to File: January 26, 2004
Failing Component: Electrical System
Summary: Complaints that the vehicle has reduced power and will not go over five miles an hour and the traction control message is displayed on the dic. Gm voicemail log

Any ideas on how to find out what the recommended fixes were for these problems??

Thx!

In a situation like this I would suggest to clear all codes and see which ones reset. Codes are intended to be fixed from lowest number first. Not a 100% perfect system, but it is a guide, a starting point. I once diagnosed a vehicle with your exact symptoms of erratic power one moment and fine the next, it was the either the MAF sensor failing or the throttle control failing, I forget which. Using a diagnostic tool, it was possible to see the MAF/throttle reading suddenly start to jump all over the place, as the car was being driven, ie using live data. (Do not attempt to do this as the driver!) Remember that modern cars do not have a mechanical connection between the gas pedal and the throttle valve, so problems in that area can have very serious results. Previously (with a mechanical linkage) the engine would respond to pedal input somewhat (it might stall, but at least it responded), even if the sensors were out. Now a problem results in no power and no response at all.

What are the lowest code numbers you are getting?