VSS code 24
- Thread starter GNRick
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I'm basically pulling this from the archives of my mind, so it might not be 100% correct.
I think that GNX style dashes use a pulse simulator to simulate the rotating speedo that reflects pulses of light into the VSS Sensor, then the VSS converts them to the signal that the ECM can use. Where is this pulse simulator? No idea, probably behind the dash somewhere. I would venture to guess that it is not working.
In order for this simulator to work, I believe that the speedo cable is spliced therefore I would side with turbo2nr and say that your cable is broken.
The VSS I believe is located behind the radio. Maybe someone else can chime in on that. I know that it's in that general area. It's a small green box about the size of a pack of Newports that has a Green, Red and Black wire running into it from the general speedo area.
That's about all I can remember, and like I said it might not be 100% correct.
I think that GNX style dashes use a pulse simulator to simulate the rotating speedo that reflects pulses of light into the VSS Sensor, then the VSS converts them to the signal that the ECM can use. Where is this pulse simulator? No idea, probably behind the dash somewhere. I would venture to guess that it is not working.
In order for this simulator to work, I believe that the speedo cable is spliced therefore I would side with turbo2nr and say that your cable is broken.
The VSS I believe is located behind the radio. Maybe someone else can chime in on that. I know that it's in that general area. It's a small green box about the size of a pack of Newports that has a Green, Red and Black wire running into it from the general speedo area.
That's about all I can remember, and like I said it might not be 100% correct.
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your code 24 doesnt indicate a "bad "or defective "VSS (vehicle speed sensor) module , it means only that the VSS isnt sending a signal to the ECM , and the accellerator is depressed for more than 20sec(i beleive thats the time ) and the car is not in park which sets the code .
if your speedo isnt working the VSS doesnt affect speedo it only registers pulse when it does spin . if the speedo doesnt spin no pulse ,thats why the code , since you claim speedo /odom doesnt work most likely the speedo cable broke to your VSS simulator
if your speedo were working then the simulator could be the problem ,
not that this is your problem but just some info
you can get a code 24 even if the speedo works and the VSS is OK , one of the conditions for code 24 is if car was revved for a long time and not rolling and not in park the code 24 will show up ,as it did on my car , I was in park holding a high rev and got the code 24
it wasnt speedo cable or VSS . the nuetral start at the top side of the base of the strg column also signals the car when it is in park , my switch had gotten bumped out of adjustment redoing some gauge wiring and the ecm didnt know i was in park
, most scan tools will show when the car is in park which made it easy to adjust .
if your speedo isnt working the VSS doesnt affect speedo it only registers pulse when it does spin . if the speedo doesnt spin no pulse ,thats why the code , since you claim speedo /odom doesnt work most likely the speedo cable broke to your VSS simulator
if your speedo were working then the simulator could be the problem ,
not that this is your problem but just some info
you can get a code 24 even if the speedo works and the VSS is OK , one of the conditions for code 24 is if car was revved for a long time and not rolling and not in park the code 24 will show up ,as it did on my car , I was in park holding a high rev and got the code 24
it wasnt speedo cable or VSS . the nuetral start at the top side of the base of the strg column also signals the car when it is in park , my switch had gotten bumped out of adjustment redoing some gauge wiring and the ecm didnt know i was in park
, most scan tools will show when the car is in park which made it easy to adjust .
VSS on the GNX style dash
The VSS on the GNX style instrument panels that I've built over the past 8 years or that were built by AVC/Tony DeQuick prior to that use an external VSS that connects inline with the upper/lower speedometer cable. It's very possible the unit may have quit working and that's the source of your 24 code. As stated in a previous post, it could also be the speedometer cable. Check the cable and if it's not frayed/broken, it's probably the VSS. Call or email Performance Instruments (www.gnxdash.com) and we'll get you back up and running.
Tom Houser
Performance Instruments
www.gnxdash.com
The VSS on the GNX style instrument panels that I've built over the past 8 years or that were built by AVC/Tony DeQuick prior to that use an external VSS that connects inline with the upper/lower speedometer cable. It's very possible the unit may have quit working and that's the source of your 24 code. As stated in a previous post, it could also be the speedometer cable. Check the cable and if it's not frayed/broken, it's probably the VSS. Call or email Performance Instruments (www.gnxdash.com) and we'll get you back up and running.
Tom Houser
Performance Instruments
www.gnxdash.com
After all those great replies I decided to go out and have a look at it. Here is what I found- there is a little square looking box in line with the speedo cable, where the garden hose connections are screwed on to. There are wires going to this box, and the wires have pulled away. It appears that one wire is broken. The wires seem to go into the fire wall. So now what?
Hey, by the way, the car is for sale. I have it listed in the Cars for Sale thread. The speedo/odometer issue just happened 2 days ago, so add 120 miles to the odometer reading of about 130,000. This includes the original odometer reading of about 60k, and about 70k on the VDO odometer. Its been awhile since I've looked at the original odometer, though.
Hey, by the way, the car is for sale. I have it listed in the Cars for Sale thread. The speedo/odometer issue just happened 2 days ago, so add 120 miles to the odometer reading of about 130,000. This includes the original odometer reading of about 60k, and about 70k on the VDO odometer. Its been awhile since I've looked at the original odometer, though.
Answer to "What Now"
It's new VSS time (the littlesquare box between the two cables).
Cost to repair is $95 plus shipping. Email me to order one.
Tom Houser
Performance Instruments
www.gnxdash.com
It's new VSS time (the littlesquare box between the two cables).
Cost to repair is $95 plus shipping. Email me to order one.
Tom Houser
Performance Instruments
www.gnxdash.com
Do I need the 340 011 ?
http://www.vdona.com/onlinecatalogs/performance catalog/PerfCatHTML/perfcatsendersframes.html
http://www.vdona.com/onlinecatalogs/performance catalog/PerfCatHTML/perfcatsendersframes.html
DON'T USE THE VDO VSS!!!
The VSS offered by VDO is NOT compatible with the Buick ECM. VDO's unit is a 16 pulse hall effect sender and the factory setup is 2 pulse. The VDO VSS will run a VDO Electronic Programmable Speedometer but NOT work with the ECM.. you'll still get the 24 code! Trust me on this... I wouldn't feed ya BS just to sell you a part. The ONLY place you are going to find a VSS that works with that dash is at Performance Instruments. You can waste your time if you want but you'll end up calling me in the end.
Tom Houser
Performance Instruments
www.gnxdash.com
The VSS offered by VDO is NOT compatible with the Buick ECM. VDO's unit is a 16 pulse hall effect sender and the factory setup is 2 pulse. The VDO VSS will run a VDO Electronic Programmable Speedometer but NOT work with the ECM.. you'll still get the 24 code! Trust me on this... I wouldn't feed ya BS just to sell you a part. The ONLY place you are going to find a VSS that works with that dash is at Performance Instruments. You can waste your time if you want but you'll end up calling me in the end.
Tom Houser
Performance Instruments
www.gnxdash.com
I recently purchased an '87 GN with an AVC GNX style dash. Originally, I noticed the scanmaster would read only ~ 12 mph at freeways speeds, while the speedo would read normally. Well, close to it, anyway...maybe a few mph slow (5-8). At other times, the scanmaster indicated the actual speed. Now, the mph is consistently 0 on the scanmaster (speedo still okay). The main reason I want to resolve it, is cause...no TC lock up.
So what's the number one predicted culprit?
TIA,
Terry
So what's the number one predicted culprit?
TIA,
Terry
Possible Culprit
If the speedo reads fine but the Scanmaster shows off by that much... I think it's time to check the VSS. It will be located between the upper and lower speedometer cable somewhere behind the brake master cylinder.
Tom Houser
Performance Instruments
If the speedo reads fine but the Scanmaster shows off by that much... I think it's time to check the VSS. It will be located between the upper and lower speedometer cable somewhere behind the brake master cylinder.
Tom Houser
Performance Instruments
Hi Tom,
I emailed you a couple of times but got no response. I have to order the lower speedo cable from you. I thought you said the price was around $55 but I can't remember and I can't find that email. Please reply to Rudydog33@ameritech.net . Shipping is to 61821. The car is sitting right now waiting for a headgasket (or two). Thanks.
Rick Pikowsky
I emailed you a couple of times but got no response. I have to order the lower speedo cable from you. I thought you said the price was around $55 but I can't remember and I can't find that email. Please reply to Rudydog33@ameritech.net . Shipping is to 61821. The car is sitting right now waiting for a headgasket (or two). Thanks.
Rick Pikowsky
Hey Tom -
I think I found the VSS, but it was hard to get to (isn't almost everything on cars?), so before going any further, I thought I'd confirm that this is it:
In case you can't tell, it's almost directly below the brake master cylinder.
There's one gray wire coming from it, going through the firewall.
It doesn't look all that new though. The GNX style dash was installed 19K miles ago (though it could've been 10 years ago), so I would think it'd look almost new.
Thanks,
Terry
I think I found the VSS, but it was hard to get to (isn't almost everything on cars?), so before going any further, I thought I'd confirm that this is it:
In case you can't tell, it's almost directly below the brake master cylinder.
There's one gray wire coming from it, going through the firewall.
It doesn't look all that new though. The GNX style dash was installed 19K miles ago (though it could've been 10 years ago), so I would think it'd look almost new.
Thanks,
Terry
That's it!
Yep... thats the external VSS you're pointing at..
Tom Houser
Performance Instruments
www.gnxdash.com
Yep... thats the external VSS you're pointing at..
Tom Houser
Performance Instruments
www.gnxdash.com
Okay, bingo. I'll check the that wire's connection under the dash.
Question, does the VSS you supply come with the wire attached? I ask, because the connection at the VSS looks "permanent", as if it's hardwired into it. And...it looks a little loose...there's a little protective boot that looks like it's supposed to be affixed to the VSS body, that's now separated. Though I couldn't pull the wire from the VSS with a mild tug.
And do you know where it terminates at the other end?
Mega Thanks,
Terry
Question, does the VSS you supply come with the wire attached? I ask, because the connection at the VSS looks "permanent", as if it's hardwired into it. And...it looks a little loose...there's a little protective boot that looks like it's supposed to be affixed to the VSS body, that's now separated. Though I couldn't pull the wire from the VSS with a mild tug.
And do you know where it terminates at the other end?
Mega Thanks,
Terry
GNRick - Hmm...but my speedo gauge works, so I know the cable is okay. Hey, where'd you get your external VSS, and how much was it? I'm on a major budget right now (not employed), and the one source I've gotten a quote from sounds very high.
Hey Tom - In reading this thread: http://www.turbobuick.com/forums/showthread.php?s=&threadid=100857 It almost sounds like maybe it could also be that little green box under the radio? Is that possible?
Terry
Hey Tom - In reading this thread: http://www.turbobuick.com/forums/showthread.php?s=&threadid=100857 It almost sounds like maybe it could also be that little green box under the radio? Is that possible?
Terry
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