: 05 xlr trac light stabilatrac and abs lights on



jude_s1
07-08-10, 08:06 PM
Hi guys i have a problem that started on my 05 xlr last week :bonkers:when i get on the highway and reach about 70 miles an hour if i try to kick it down to go faster the abs trac and stabilatrac warnings start then i slow down to 65 or 60 miles an hour and try to use the cruise it does not function at all until I pull over and restart the car. anybody have any thoughts on this.:confused:

ccclarke
07-08-10, 11:40 PM
Good and bad news: Your car is working as designed. Because the Adaptive Cruise Control is integrated with the suspension system, (for one) it will not operate if there is a fault wihin the system(s). (--This is a good thing.) You probably have a suspension-related fault. (Any other DIC messages?)
A quick diagnosic with a dealer's Tech 2 will find out what's wrong. A suspension-related fault will display one of the following messages on the DIC:
SHOCKS INOPERATIVE
SERVICE RIDE CONTROL
MAXIMUM SPEED 129 km/h (80 MPH)

(Other system failures can flag these as well.) A fault code will reside in memory and can be pulled by the Tech 2.

CCC

ewill3rd
07-09-10, 09:09 AM
No telling without finding out what code is setting.
Even then anything anyone here tells you would be just a guess.

jude_s1
07-09-10, 03:39 PM
Good and bad news: Your car is working as designed. Because the Adaptive Cruise Control is integrated with the suspension system, (for one) it will not operate if there is a fault wihin the system(s). (--This is a good thing.) You probably have a suspension-related fault. (Any other DIC messages?)
A quick diagnosic with a dealer's Tech 2 will find out what's wrong. A suspension-related fault will display one of the following messages on the DIC:
SHOCKS INOPERATIVE
SERVICE RIDE CONTROL
MAXIMUM SPEED 129 km/h (80 MPH)

(Other system failures can flag these as well.) A fault code will reside in memory and can be pulled by the Tech 2.

CCC

thanks for the info and thank god for gmpp its going in next week for an alignment check and wheel balance i still havent purchased the tech yet but Cadillac has got me until 2011. already paid for the warranty though. I brought the car in for an oil change last month and they noticed some seapedge from the oil pan and valve covers so they did that job for me under warranty I figured that job for 1500 or so what do you think I just got a 0 bill so im not realy sure what the labor rate is.I know gaskets arent that much.any way ill let you know what the code is its going in on Tuesday.:cool2:also had abs light

ccclarke
07-10-10, 04:53 AM
Good for you! You have covered yourself as much as humanly possible. The GMPP warranty is the best insurance you can buy for an XLR that has outlived it's standard factory warranty. (GMPP is the only warranty that covers the Folding Top.) Your ACC fault may be symptomatic of an issue within the overall system since the brakes, transmission and suspension system all tie in to the ACC system. The dealer's Tech 2 is the best tool to diagnose the issue and determine if a valid fault is present.

ewill3rd is an awesome source of information. He's forgotten more than most folks will ever learn about the XLR and has the experience and know-how to diagnose the exact symptoms you describe. Wherever you decide to take your car for maintenance, make sure they have a certified XLR tech (like him) to work on it. A car as complex as the XLR requires specific training and in-depth knowledge to ensure it's fixed right the first time. Good XLR techs are worth their weight in gold!

Let us know how this turns out, so we all learn from it.
CCC

ewill3rd
07-10-10, 10:15 AM
jude, I have seen an odd issue on two cars (and I service a lot of these) where the ABS harness had issues.
I wouldn't call it a nightmare to fix (not to say that this is the problem) but to service the harness I basically had to the remove half of the driveline and replace the main harness that runs from where the engine controller is all the way down the torque tube and it contains all the wiring for the transmission, rear suspension, and ABS harnesses for the back sensors.

It really could be a lot of things. The steering sensor could be glitching or you could have a faulty sensor. Seems odd that it would wait until you juice it at 70 but if the warning lights come on there is a code in there and once we get it we can look toward a specific problem.

jude_s1
07-29-10, 12:20 AM
I got the car back from Tremonte Cadillac in Branford conn. they replaced a right front wheel hub and sensor it looks like the two codes they pulled were P1793 and C0040 :thepan:I left the dealer got on the hiway and before I got halfway home the lights came back on. needless to say its going back tomorrow. I guess I can look at the bright side I got a free hub and bearing in the right front .:dammit:......... I brought The Car back but before i did i used my buddys scanner (Matco Eliminator) I pulled three codes three in history p1790 p1793 and c0040 one current p1790the Current P1790 I pulled out of secondary transmission. Service writer said no such code p1790 I showed him my scanner and told him to call Cadillac tech support. well we will see.Any thoughts on this p1790 code in secondary trans causeing abs stabillatrac and trac lights to come on.

ccclarke
07-30-10, 02:58 AM
In my shop manual, the C0040 code points to a wheel speed sensor issue. The 1793 DTC indicates a wheel speed issue beween the ECM and TCM. The Tech 2 is one of the best tools to troubleshoot the XLR. Aftermarket scan tools can't look nearly as deep. The XLR has two data busses and requires a special interface (CANdi) module to access both. Let us know how this plays out.

CC

jude_s1
07-30-10, 05:55 PM
Clark What about the p1790 this code they also came up with and did not know what it was. I have to get a tech

ccclarke
07-30-10, 09:42 PM
The only P1700 series code in my shop manual is P1793. This is why you need to have a Tech 2 when isolating faults in the vehicle. (See previous post.) Aftermarket code pullers are primitive in comparison.

A Tech 2 doesn't just run comprehensive diagnostics, it has the ability to interact with sub-systems and individual components throughout the vehicle, -like Folding Top manifold solenoids for example. It can place a test pattern on the HUD to ensure the display is working properly. The list goes on and on. I spent an entire afternoon taking hundreds of photos of the display as I scrolled through the menu lists to learn what it could do. They aren't cheap though.

The XLR is one of the most complex vehicles on the road, and isn't the kind of car you let anyone work on. Your best bet is a certified GM XLR tech; anyone else is a gamble. And being Stabilitrac and ABS are safety issues, I'd opt for the best for my peace of mind.

CCC

ewill3rd
07-30-10, 09:43 PM
I think you mean the P1793

Here is some info from the diagnostic chart:

Circuit Description
The engine control module (ECM) sends wheel speed data to the transmission control module (TCM). The data is sent to the TCM through a communication network called the controller area network (CAN). Two circuits are used to communicate CAN data between the ECM and TCM. A fault in the CAN will not cause DTC P1793 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P1793.

When the TCM receives invalid wheel speed data from the ECM, then DTC P1793 will set. DTC P1793 is a type C DTC.

DTC Descriptor
This diagnostic procedure supports the following DTC:

DTC P1793 Wheel Speed Signal

Conditions for Running the DTC
• The engine run time is greater than 6 seconds.

• No other CAN errors are present.

Conditions for Setting the DTC
The TCM receives no valid wheel speed data from the ECM for 2 seconds.

Action Taken When the DTC Sets
• The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).

• The TCM inhibits autograde braking.

• The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.

• The TCM stores DTC P1793 in TCM history.

Conditions for Clearing the DTC
• A scan tool can clear the DTC.

• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.

• The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.


I'm not sure what it means in your case but the short of it is the ECM wasn't sending VSS data to the TCM for some reason.

ccclarke
07-30-10, 10:38 PM
Bill,

I think he's trying to get clarification of an (erroneous?) code (1790) reported by an aftermarket scan tool.

CCC

jude_s1
07-31-10, 12:06 AM
nooooooo :thepan:they ALSO PULLED A 1790 CODE ON THERE TECH 2 AND IGNORED IT BECAUSE IT ALSO HAD THE C0040 and The P1793.they diagnosed it changed the right front speed sensor,When i picked it up and went home it did the same thing at 70miles an hour. that's when i borrowed the Matco scanner from my friend I had no problem getting the three codes I did not find out until i brought the car back, the next day. That they also pulled the p1790 code, and ignored it, because they did not know what it was. I showed him I had the same code on my scanner.and told him he should call tech support. I hope that's a little clearer. Also that is the only code present now. the other two are only reading in history so part of there diagnosis is right.when i brought the car in the light s were on all the time when the problem first started it was at 70 miles an hour.So it seems it developed two problems in a short period of time. This code is reading P1790 in secondary transmission.on the tech 2 have not herd back from them yet the guy there is a Certified xlr tech he's young though, but seems to know What he's talking about. I was with Chevy for 15 years I left in 03 so i know the tech 2 is the best to have for this vehicle. Ill worry about that in two years when the warranty is out. Thank's see what you can come up with I "m waiting for them and that's not till Monday

ewill3rd
07-31-10, 12:13 PM
There is no such thing as a P1790.
I searched the service manual for XLR from 2004 until 2009.

jude_s1
07-31-10, 03:01 PM
That's what they said too, but it is there, I will keep you posted!!! The only time I ever got false codes it was a bad pcm. on a 99 Astro van totally different Animal.

jude_s1
07-31-10, 03:12 PM
Is there any tie in between traction control abs stabillatrac lights and the trans. the only time I ever got false codes it was a pcm on a 99 astrovan much different vehicle.

ewill3rd
08-01-10, 11:01 AM
It doesn't matter if the car sets that code or not. There are no diagnostics for it so even if it is there what are you going to do?
At any rate unless it is capable of commanding the MIL on it shouldn't much matter.

I don't understand the last question.
Is there a difference between ABS/TCS/Stabilitrak and the transmission?

jude_s1
08-01-10, 03:02 PM
Please try to read the post over. I am asking if there is a tie in, not a difference. I want to know if there is connection between the transmission and stabilatrac I can't figure why this false code P1790 is setting at 70 miles an hour. Yes and it does cause the abs trac.control and stabilatrac lights to come on. it is the only code setting in present memory.I hope that's clearer........................................... .................................


I talked to Cadillac this morning they are trying a new ecm. have not herd back yet.

jude_s1
08-02-10, 05:14 PM
well they replaced the ebcm and that seems to have taken care of it. if that makes any sense. It looks Like they wrote it up for warranty reasons as an intermittent problem in the ebcm causing code C0400 and false code in present memory. Thanks guys for your help. when I asked him how he figured it out, he just said. An experienced guess.So much for procedure.