Shazaam! 1995 Deville DIC instant "upgrade" - Page 3

omarietta · #31 (**permalink**) 06-10-05, 12:40 AM

Quote:

Originally Posted by caddydaddy

181F, was it not fully warmed up? Mine was running between 205-213 this morning.

That's weird. My car stayed stable between 164-171F. I drove about 35 miles on my way back from work. Does the standard 4.9 run cooler than the N*? Is my car on crack?

Eric2203 · #32 (**permalink**) 06-10-05, 01:34 AM

I have a question. Will making the DIC believe that the car is an Eldo/Seville affect anything other than what info is displayed ?

smooth3d · #33 (**permalink**) 06-10-05, 03:28 AM

Add me to the upgraded club, YYYYYYeeessssssss now i have rpm & temp. I love this.

delzy · #34 (**permalink**) 06-10-05, 03:44 AM

I've got a couple of brand new FSM's for 94's and 95's I'm peddling on eBay for $86, but I'll sell them for $66 shipped USPS priority mail to anybody who wants them on this forum. just let me know. Just email beartooth-@-gmail.com . Get rid of the dashes. Apparently I can't get PM's.

96CADDYDEVILLE · #35 (**permalink**) 06-10-05, 09:26 AM

Has Anyone Figured This Out For A 96?????

Kdirk · #36 (**permalink**) 06-10-05, 11:02 AM

eric2203-

To answer your question, as far as I have been able to tell it does not. I had this same concern when I first did this. Because of my uncertainty I road tested this change myself for 2 weeks before I posted it here - I didn't want to say anything until I knew it would work without any strange side effects. I checked for codes every day, and ran all systems through their paces just to see if anything unusual or unexpected would come up, and nothing did.

Thus, changing this parameter ONLY changes the display mode of the DIC in as much as what items are shown on the DIC at the bottom of the cluster. Nothing else changes on the digital displays for the speedo, climate controls, fuel gauge etc.

Moreover, it does not change the interactions with any of the other modules or electronics in the car (I have to believe that all kinds of DTC's would show up if it did) as far as can be determined without being able to monitor the car's data lines in real time - which would require specialized equipment that I (and probably most here) do not have. In other words, the car still know's it's a Deville, just the DIC display mode is setup to show the extra items available on the Eldo and Seville. The change appears to be completely internal to the operation of the cluster.

The one thing that occured to me that I haven't checked is the top end speed limiter. Does anyone here know if the 1995 Deville had a top end cutoff that was different than the Eldo or Seville? I am strictly speculating here (I won't drive my car fast enough to find this out anyway) but if there was a difference, this may cause the top speed cutout to change to whatever it was on the Eldo/Seville in 95.

Then again, I believe the electronic "governor" was controlled by the PCM, and not by the IPC so it probably won't have any effect. As well, OBDI didn't have a reprogrammable top-speed cutout the way OBDII (post 1996) systems do, or at least it required burning a new PCM PROM to change it which is beyond the reach of most people.

So, the short answer is - after 2 weeks running this way on my vehicle- that there are no perceptible problems associated with doing this. As I had pointed out previously, this seems to be a change that only instructs the cluster to either allow or supress these 3 extra items on the display.

I specukate that since the Seville and Eldo were considered higher performance vehicles that some engineer at GM felt drivers of those cars would want this information and that Deville drivers weren't interested so they created a way to omit this data from the display based on how the cluster was programmed.

If anyone here can say positively that my line of thinking on all this is bogus, then I will stand corrected. Withstanding that, I'm confident that my interpretation of what is going on and how this all works is correct.

Kevin

95Concours · #37 (**permalink**) 06-10-05, 04:12 PM

Thanks again for the email, it worked, was easy to do, took all of 3 minutes... Very happy to finally be able to see RPM, TEMP & Volts...

Eric2203 · #38 (**permalink**) 06-11-05, 01:00 AM

Thanks Kevin. Didn't know you'd road-tested for 2 weeks (or I missed that if you mentioned it before). Looks like I'll do it then. in my opinion, you're right to think it shouldn't affect more. After all it's an IPC Override, not PCM (which would I guess affect the whole car). Though what do I know... ? lol

100 · #39 (**permalink**) 06-11-05, 11:30 AM

"The best thread of the year!" (so far)

This is so cool. I respect your attitude to wonder, investigate, and test things. By the way, my temperature stays between 200-210 F. Until the thermostat first opens, it goes up to almost 220 F. But once it starts cycling, it would stay around 205 F.

N0DIH · #40 (**permalink**) 06-11-05, 12:55 PM

Quote:

Originally Posted by omarietta

That's weird. My car stayed stable between 164-171F. I drove about 35 miles on my way back from work. Does the standard 4.9 run cooler than the N*? Is my car on crack?

Yours is on crack, the stat is dead. Go get a new one. For summer this really isn't an issue (an no, this temp here, will not affect open/closed loop, it must be much cooler, like 130F to do that, I dubunked that myth years ago), but winter time you will unhappy at the lack of heat.

You might be able to run a 180 thermostat, it might make a little more power, but the cooler stat will make the cooling fans run at late times and temperature range of the engine will be wider, so it will run 180 on the stat, then the fans don't turn on till 220 or so, then turn off at 200-205, but the therm is wide open trying to get to 180. So honestly, the the factory spec'd 195 is really the best. Less temp shock to the engine. You can get modified fan temp switches from Summit/Jegs for a TPI car. Note the 305 TPI cars ran slightly warmer than the TPI350 cars. But in the aftermarket, the switches are the same. I think Hypertech is the company who sells them.

I would swap it now, it likely will improve fuel economy some also.

Even my LT1 with a factory spec'd 180 degree thermostat runs right at a high of 92C in traffic, but on the open road it runs around 89C. Remember on a LT1 the cooling flow is reversed, so temps are measured in different locations.

toneout · #41 (**permalink**) 06-12-05, 10:56 AM

I am updated too. Thanks for the directions kdirk, they were easy to follow. What other abilities are hidden? Only the engineers know!

johnp · #42 (**permalink**) 06-12-05, 11:27 PM

Hello Kdirk,

I just upgraded the DIC on my 1994 Deville 4.9 and it works GREAT. Your step by step instructions were right on !

The lack of info on the stock DIC was a nuissance. Maybe this was just a small oversight from the talented engineers at Cadillac.

I am glad to see great members like you on this forum who are sharing and helping other members.

Thank you for your help !

JP

Eric2203 · #43 (**permalink**) 06-13-05, 01:57 AM

Did it too. Works great.

Thanks again.

Night Wolf · #44 (**permalink**) 06-13-05, 03:40 PM

That is definitly cool! honestly, I thought these cars had those options the whole time....

does it change the performance of the car? shift points? I would think the Eldo/Seville would be more *sporty* then the DeVille, so if you are telling the computer it is now an Eldorado, it may try to act like one

caddydaddy · #45 (**permalink**) 06-13-05, 03:47 PM

Quote:

Originally Posted by Night Wolf

does it change the performance of the car? shift points? I would think the Eldo/Seville would be more *sporty* then the DeVille, so if you are telling the computer it is now an Eldorado, it may try to act like one

But you're not telling the computer it's an Eldorado, you're telling the IPC that it's a Eldo.