PDAS green light mod (when adding bulb is not enough)
#16
Instructor
Thread Starter
https://rennlist.com/forums/967760-post3.html
utah,
in your last pic your gauge shows a green light in the top left "corner" of the gauge. The PDAS light in mine is two over (window 3 viewed from front, or window 2 viewed from backside) and is a pictogram of 4 wheels? (as per garrett's pic in post above).
utah,
in your last pic your gauge shows a green light in the top left "corner" of the gauge. The PDAS light in mine is two over (window 3 viewed from front, or window 2 viewed from backside) and is a pictogram of 4 wheels? (as per garrett's pic in post above).
The link in frankvan's post is pretty telling...Whereas Utah's newfound light looks more like an ABS type icon, the one in frankvan's link looks more like a traction-control type of icon.
It may be that Utah has done most of the dirty work and would only need to move the wire once more to light up the more appropriate traction-control light.
Wouldn't this be the perfect time for St. Adrian to weigh in?
Utah still gets the Geek Squad award for bringing this to light!
It may be that Utah has done most of the dirty work and would only need to move the wire once more to light up the more appropriate traction-control light.
Wouldn't this be the perfect time for St. Adrian to weigh in?
Utah still gets the Geek Squad award for bringing this to light!
#17
Rennlist Member
Hmmm... this is getting pretty interesting. I only had one green light, and that's the one I lit. It appears there are different gauges out there.
I'll try to get a good picture of what lights my gauge has, but I don't have the green AWD-looking light or the red one. I've got a green ABD light and a red ABD light.
I'll try to get a good picture of what lights my gauge has, but I don't have the green AWD-looking light or the red one. I've got a green ABD light and a red ABD light.
Fascinating posts!!!
#18
Rennlist Member
...I couldn't take the suspense so I went to take out the Porsche to verify what I said in the above post...
So, it's when I turn the key to what would be the ACC position that I can get my gauges to go into Christmas tree display and that's the picture that I've taken. As you can see, I get the red AWD light right away. Once I turn the car on, it stays lit for a second or so before going out.
I took a flash light to try to see the icon of the light that's to the left of it and I could see the AWD icon on it as well!
Now, because of all this discussion, I went ahead and tried the PDAS switch down on the console for well over ten seconds and the LED never lit, nothing on the dashboard came up, and I couldn't detect any locking of differentials or token understeer characteristics that one would get if the front wheels were "locked." I tried this in neutral and in first gear with the clutch in but to no avail.
This makes me wonder if my PDAS is working at all! I would think I'd have handling issues or that my red PDAS light would stay lit, indicating a fault. A potential can of worms that I didn't even know I had!
Am I missing something here? I'm going to do a search on this forum as well as consult Adrian's book to see if I can make sense out of my new-found problem.
So, it's when I turn the key to what would be the ACC position that I can get my gauges to go into Christmas tree display and that's the picture that I've taken. As you can see, I get the red AWD light right away. Once I turn the car on, it stays lit for a second or so before going out.
I took a flash light to try to see the icon of the light that's to the left of it and I could see the AWD icon on it as well!
Now, because of all this discussion, I went ahead and tried the PDAS switch down on the console for well over ten seconds and the LED never lit, nothing on the dashboard came up, and I couldn't detect any locking of differentials or token understeer characteristics that one would get if the front wheels were "locked." I tried this in neutral and in first gear with the clutch in but to no avail.
This makes me wonder if my PDAS is working at all! I would think I'd have handling issues or that my red PDAS light would stay lit, indicating a fault. A potential can of worms that I didn't even know I had!
Am I missing something here? I'm going to do a search on this forum as well as consult Adrian's book to see if I can make sense out of my new-found problem.
#19
Three Wheelin'
August-
#1 it looks like someone has pulled your "check engine" light. It should be lit up to the left of the anti-lock light.
You should hear the PDAS locking when you twist the **** in front of the gear shift, even with the engine off. Should also hear them unlock when you twist the **** to disengage. Only the LED in front of the **** will light up when it's engaged - unless you do the mod mentioned hear to have the green PDAS icon light up.
You will definitely be able to hear the diff locks engage and disengage with the engine off.
Anyone know what the top light #2 is? If #1 is a green brake-icon, #3 is green PDAS, #4 is red PDAS.
#1 it looks like someone has pulled your "check engine" light. It should be lit up to the left of the anti-lock light.
You should hear the PDAS locking when you twist the **** in front of the gear shift, even with the engine off. Should also hear them unlock when you twist the **** to disengage. Only the LED in front of the **** will light up when it's engaged - unless you do the mod mentioned hear to have the green PDAS icon light up.
You will definitely be able to hear the diff locks engage and disengage with the engine off.
Anyone know what the top light #2 is? If #1 is a green brake-icon, #3 is green PDAS, #4 is red PDAS.
#20
Rennlist Member
Hey nick,
I'm one of the lucky ones that don't have a CEL. IIRC, the 964s didn't get a CEL until model year 1991.
I'm surprised to hear that you can get the differentials to lock without the engine running. In any case I get nothing when I use the PDAS switch...no clunking, no lights, no nothing. I'm going to try to troubleshoot it myself, starting with cleaning the accelerometers, but may have to have my mechanic go at it.
As for the original posting intention, I did a search on PDAS and gleaned somewhere that it seems like Porsche took out the bulb for the green PDAS light on the dash because it was too distracting for drivers.
I'm one of the lucky ones that don't have a CEL. IIRC, the 964s didn't get a CEL until model year 1991.
I'm surprised to hear that you can get the differentials to lock without the engine running. In any case I get nothing when I use the PDAS switch...no clunking, no lights, no nothing. I'm going to try to troubleshoot it myself, starting with cleaning the accelerometers, but may have to have my mechanic go at it.
As for the original posting intention, I did a search on PDAS and gleaned somewhere that it seems like Porsche took out the bulb for the green PDAS light on the dash because it was too distracting for drivers.
#21
Rennlist Member
#22
Three Wheelin'
Wow I had no idea that there were so many variations on this single gauge. Mine's a '91 (plastic intake, later rear shocks).
Anyway, I'll try this bulb mod too and see how annoying it gets.
Anyway, I'll try this bulb mod too and see how annoying it gets.
#23
Instructor
Thread Starter
Looks like we've got quite the array of gauges light combos. Mine doesn't seem to be similar to any of the combos I've seen. I put bulbs in all spots and every spot lights up except the CHECK ENGINE and red ABD light.
And get a load of my "AWD" light. Looks more like an all-wheel steer light than it does and all-wheel drive light.
Anyone else out there have my combo?
And get a load of my "AWD" light. Looks more like an all-wheel steer light than it does and all-wheel drive light.
Anyone else out there have my combo?
#25
Rennlist Member
The saga continues..
Well, this thread gets even more interesting. Tonight, I had to go do the Green Light Upgrade to both of my cars (93 C4 and 90 C4). Swapped in a bulb from another location (borrowed one from the washer fluid on the 93), and the green pdas lit up when the key was turned on. I have not driven the car yet.
Now, the interesting part. On the 90 I looked for a spare bulb to swap into the green spot, and I found one installed in one of the upper spots that never lights up on either car. (the 93 did not have a bulb installed in this same spot). Swapped the bulb, and the green pdas lit up when the key was turned on. I was curious what was in the spot on the 90 where the donor bulb came from, and shined a light from behind, and this is what I found. Sorry for crappy cell phone pic. Hmmm, I didn't know our cars had adjustable ride-height control on-board, just like a 959.
I also noted that there was no bulb installed in the 90 in the CEL position as on my 93 (CEL did not appear until MY91 I believe). I put a bulb in, turned on the key, and it lit up with "Check Engine", and would not go out when the engine was started. Hmmm, more interesting shtuff.
Now, the interesting part. On the 90 I looked for a spare bulb to swap into the green spot, and I found one installed in one of the upper spots that never lights up on either car. (the 93 did not have a bulb installed in this same spot). Swapped the bulb, and the green pdas lit up when the key was turned on. I was curious what was in the spot on the 90 where the donor bulb came from, and shined a light from behind, and this is what I found. Sorry for crappy cell phone pic. Hmmm, I didn't know our cars had adjustable ride-height control on-board, just like a 959.
I also noted that there was no bulb installed in the 90 in the CEL position as on my 93 (CEL did not appear until MY91 I believe). I put a bulb in, turned on the key, and it lit up with "Check Engine", and would not go out when the engine was started. Hmmm, more interesting shtuff.
#28
Rennlist Member
I'm curious if all these different gauges have different part numbers on the PET, or if they're all the same part number but different revisions...
The all-wheel steering icon is beyond trippy...when I think of german engineering and the german propensity for logic, and then I see that icon, it makes me wonder if your gauge is even genuine Porsche. I just don't understand why that icon would be used...
The all-wheel steering icon is beyond trippy...when I think of german engineering and the german propensity for logic, and then I see that icon, it makes me wonder if your gauge is even genuine Porsche. I just don't understand why that icon would be used...
#29
Three Wheelin'
Just a guess that it's a "slipping wheels" icon. Which would be the same function as the PDAS icon.
The ride height is unmistakeable though! Wondering if that was a later revision? Did Porsche have some changes in the 964 on the table that didn't pan out? They already had the tech from the 959. If it was combined with a shock valving change, then it would a great city/pothole feature.
The ride height is unmistakeable though! Wondering if that was a later revision? Did Porsche have some changes in the 964 on the table that didn't pan out? They already had the tech from the 959. If it was combined with a shock valving change, then it would a great city/pothole feature.