position sensor

[stormshadow71]

Hi. I was wondering if anyone would know why a position sensor status would display "invalid" when looking at it on a tech 2? It should display open/mid/closed or invalid. I replaced the folding top potentiometer and the new potentiometer keeps stopping the relearn process because the switch is going invalid. I even purchased another one thinking that I may have received a bad one but the same thing. Why are the new position sensors not working? I was told the new updated ones are more reliable,but they won't work for me. I have an 04 xlr. Has this happened to anyone else? If so what should I do?

 

[xlrlist01]

Hi. I was wondering if anyone would know why a position sensor status would display "invalid" when looking at it on a tech 2? It should display open/mid/closed or invalid. I replaced the folding top potentiometer and the new potentiometer keeps stopping the relearn process because the switch is going invalid. I even purchased another one thinking that I may have received a bad one but the same thing. Why are the new position sensors not working? I was told the new updated ones are more reliable,but they won't work for me. I have an 04 xlr. Has this happened to anyone else? If so what should I do?

There is a similar question on another XLR forum. Here is what I put for that.

A potentiometer used in this way simply reads from a max voltage to a min voltage. Max and min are references provided by the FTM. As the unit moves, a wiper (inside the potentiometer) slides along the potentiometer's internal resistor travelling from one voltage towards the other. Thus the idea of getting low (or invalid) readings suggests defective wiring or failing FTM.

The following are some suggestions, if you are unsure take professional advice.

First: Consider use of proper contact cleaner on all the connectors, especially the FTM connectors and examine the connectors most carefully. Avoid WD-40, instead source proper contact cleaner. It is available for electronics and is used by audio (microphones on stage) specialists. You want the normal (lubricating) type.

Did that fix it?

No? - Second:
Suggest you look at the voltages being provided at the sensor connectors, a wiring fault or defective FTM is indicated.

To diagnose further, suggest you need to pin out the voltages at the FTM and the sensor and compare them. This requires specialist skill.

The ideal tool is a memory scope which records as a minimum the signal (wiper) voltage at the sensor and at the FTM. A difference should not arise. Better still would be to record the signal at the two places and the max and min voltage at the sensor. At the sensor, 'A' is reference high (set to 5v from the FTM), 'C' is the min voltage (the workshop manual doesn't state, but usually this is sensor ground, ie 0v, but is called 'low reference') and 'B' is the signal.

At the FTM, it looks like C13 is reference high (5v), C15 is reference low and D1, D2 and D3 the three sensor signals, (D1=Folding top position; D2=Front and D3=Rear tonneau sensors).

Never pierce insulation to take voltage readings, it causes long term problems. There are very fine wires for this purpose that slide into the back of the connectors.

HTHs

 

[HOMEGAMEROOM]

Another possibility might be that the original sensors were simple switches - they were later "upgraded" to pots. You may need to get a more current version of software for the folding top control unit for the potentiometers to function correctly.

You may want to try to put one of the original switches in it to see if it works and/or what the Tech II says.....

BTW, I live a few miles south of you - welcome!!!

 

[stormshadow71]

What is strange is that when I swapped the new sensors with the front tonneau sensor,all readings or counts looked about the same,but would not advance to next step in process...which is the folding top stowing. As soon as I put the original sensor back in,the top stowed after the front tonneau opened. The new sensors just will not work and I don't get it. I did just replace the FTC...with no change in function. I tried the new sensors where the folding top position sensors is and they will not work there. The readings or counts are from low(38) to high(199). Car never driven in or left in rain. Only 37k and connections look solid and new. Do the new FTM come already programmed with latest software? If so,I am at a loss for now. By the way, the sensors are no longer going to invalid state...found and repaired the loose screw holding sensors in place.
By the way gameroom...thanks and if you are in ever need of the use of a tech2, stop up and you can use mine. Maybe We can get together when the weather breaks and check out eachother cars.

 

[Stella]

What is strange is that when I swapped the new sensors with the front tonneau sensor,all readings or counts looked about the same,but would not advance to next step in process...which is the folding top stowing. As soon as I put the original sensor back in,the top stowed after the front tonneau opened. The new sensors just will not work and I don't get it. I did just replace the FTC...with no change in function. I tried the new sensors where the folding top position sensors is and they will not work there. The readings or counts are from low(38) to high(199). Car never driven in or left in rain. Only 37k and connections look solid and new. Do the new FTM come already programmed with latest software? If so,I am at a loss for now. By the way, the sensors are no longer going to invalid state...found and repaired the loose screw holding sensors in place.
By the way gameroom...thanks and if you are in ever need of the use of a tech2, stop up and you can use mine. Maybe We can get together when the weather breaks and check out eachother cars.

Looking in the manual is says that you have to calibrate any potentiometer when removed. Don't know if that's effecting your new ones. Also the FTM "folding top module" is an extensive job. Says you have to cut out panel supports. Yes I said cut out then expose the piece back in when done?
If you have a tech2 you need to do a step by step evaluation on all sensor parameters and check input and output signals to modules to pinpoint sensor,wiring,connection,or control module?
Good luck

 

[stormshadow71]

When you replace a position sensor, the top must be relearned with a tech2. The new sensors are extremely easy to replace and only go on one way. After I swapped these out and try to perform a relearn,the process stops. I put the old sensors in,and the top advances to where I had trouble to start...which is when the folding top stows. The original folding top sensor is bad, but again,none of the new sensors work. Readings or counts look good...that is why I am at a loss. I also ordered a new FTM and replaced that as well. No change. The module replacement was easy for me and took less than an hr to replace. I am now wondering if I need FTM reprogrammed by dealer. I thought new FTM was already programmed with latest and greatest. Can anyone confirm?

 

[Stella]

It sounds like you understand the procedures that need to happen. Are you getting any messages on he DIC? Sounds like it isn't getting the right signal to go on to the next step. Is it getting proper readings on ALL the potentiometers? Is the FTM giving the signal for the next step? You could have a solenoid issue on the valve bank. Are you getting a signal to solenoid and do you hear the valve click" open"? When you say the new sensors don't work do you mean you can't get past the original fault issue?
Also read that you must do a window normalization and folding top position procedure prior to performing the folding top learn procedure. What's coming up on the tech when it stops? Do you have a manual?
And to answer the question of sensor or switch? Their are sensors that are limit switches and ones that are potentiometers.

 

[stormshadow71]

WTF!...Unbelievable! I was swapping out the new sensors one by one and taking readings and recording the counts again(the folding top position sensor). All readings look almost identical. The first 2 new sensors once again failed with top not secure message. The 3 sensor I tried seemed to hesitate for a few seconds when the top stowed on the relearn procedure...but then FINALLY advanced to next stage when rear tonneau extended and finally took the relearn.YAY! I am still clueless as to why the other new sensors did not work,but everything works fine now! After $150 to the dealer that was "stumped",a new FTM,and 3 new sensors...it works! I just wish that I knew what the hell happened for it to start working again. I tried this before and they all failed before with top not Sucure. I do have the shop manuals as well($200).Oh well, I am so happy right now. Thanks again to all who responded and tried to help! Hugs and kisses.

 

[Stella]

No problem hope it stays working for ya. Could you of had a iffy connection? I always use dielectric on any connections. Could a switch not be in range. I haven't had to work on any of the switches to know the mechanics behind it, but maybe one of the potentiometers isn't reading "the gap is to big".
I would think these tops are very touchy and setting have to be close to perfect to work properly. What was you tech2 reading when the top wasn't functioning.
Well good luck with the top hope it all works out for you.

 

[ald42]

top?

WTF!...Unbelievable! I was swapping out the new sensors one by one and taking readings and recording the counts again(the folding top position sensor). All readings look almost identical. The first 2 new sensors once again failed with top not secure message. The 3 sensor I tried seemed to hesitate for a few seconds when the top stowed on the relearn procedure...but then FINALLY advanced to next stage when rear tonneau extended and finally took the relearn.YAY! I am still clueless as to why the other new sensors did not work,but everything works fine now! After $150 to the dealer that was "stumped",a new FTM,and 3 new sensors...it works! I just wish that I knew what the hell happened for it to start working again. I tried this before and they all failed before with top not Sucure. I do have the shop manuals as well($200).Oh well, I am so happy right now. Thanks again to all who responded and tried to help! Hugs and kisses.

It works now because you did not give up as the dealer did "stumped".good job and look how much info we all now have!! well done. I have a friend do a top relearn on mine once a year. Al

 

[airmike]

It works now because you did not give up as the dealer did "stumped".good job and look how much info we all now have!! well done. I have a friend do a top relearn on mine once a year. Al

Al, you have a friend do a top relearn once a year? I would like to hear the reasoning. That is NOT a knock! I just want to know something I don't now. I am actually hesitant to do anything other than oil etc.. because I could make it worse. Don't fix it if it ain't broke you know.

 

[Stella]

Al, you have a friend do a top relearn once a year? I would like to hear the reasoning. That is NOT a knock! I just want to know something I don't now. I am actually hesitant to do anything other than oil etc.. because I could make it worse. Don't fix it if it ain't broke you know.

If anything it would recalibrate the sensors to the linkages/arms their reading off of. In case there's movement or wear it recalibrates them.

 

[05 GRAND DADDY]

Just wondering how this is done???


Sent from my iPhone using Tapatalk
Dan & Wendy
"05 GRAND DADDY"

 

[GizmoQ]

If anything it would recalibrate the sensors to the linkages/arms their reading off of. In case there's movement or wear it recalibrates them.

EXACTLY! My dealer does my relearn every Spring after the temps are above 70*F, i.e., my summertime mode when I'm most likely to be cycling the top.

 

[stormshadow71]

Well, it looks like I spoke to soon. My smile from ear to ear has turned to frowns. I came home after work and tried the top and after it stowed I got the top not secure yet again. I checked with tech2 and it shows "folding top position sensor" bad....one of the NEW ones that I just bought. I checked counts and it now shows status as "invalid". The counts go down on the low end to 38. yesterday, as I manually move the top , it would go "extended,then mid,then retracted as it stowed. why it is not working today and showing "invalid" is beyond me. Back to the drawing board...

 

[V Happy]

-position-sensor

I think I would start looking at wiring or connection failure. Sorry u are back into this. Intermittent usually turns out connection or broke wire on flex area. I have the books and tech 2 but never figured out how to get the count readings off the tech 2 I also don't live far from u Uniontown. When the weather brakes I may be able to help figure out by taking readings and voltages off mine. Two of us got together last fall . George lives near valley view . He drove his 05 out to Uniontown and we corrected his top issue by putting our heads together. Good luck and keep us up to date
V Happy

 

[ald42]

If anything it would recalibrate the sensors to the linkages/arms their reading off of. In case there's movement or wear it recalibrates them.

Stella said it right, that's why I have mine done once a year. keep chewing away at it, I know it can drive u nuts but you'll get it done.keeping my fingers xed for you.good luck. Al

 

[05 GRAND DADDY]

Stella said it right, that's why I have mine done once a year. keep chewing away at it, I know it can drive u nuts but you'll get it done.keeping my fingers xed for you.good luck. Al

Al
What do they do to relearn the top? When I asked the Cadillac dealer they say there is no maintenance for the top not even like grease to the sliding parts which I would think moving parts would need it someday???


Sent from my iPhone using Tapatalk
Dan & Wendy
"05 GRAND DADDY"

 

[stormshadow71]

Thanks guys....that sounds like a plan. When the weather gets nicer I would like to get together. The tech2 has a snapshot feature which let's you record the readings. Also, you can see the counts and sensors status as you move the top manually. I am going to check wiring once again and see if maybe there is a loose wire possibly. To be continued....

 

[ald42]

relearn

Al
What do they do to relearn the top? When I asked the Cadillac dealer they say there is no maintenance for the top not even like grease to the sliding parts which I would think moving parts would need it someday??


Sent from my iPhone using Tapatalk
Dan & Wendy
"05 GRAND DADDY"

HiDan,the tech plugs in the tec2 and commands a top relearn,no biggie,next time your in for serv. ask them to do it.it's part of MY maint.!!if they don't know what it is find a new dealer/mech. AL