PCM year swap questions 98-->00 (guru's inside please)

[John_D.]

I'm thinking about swapping a '00 pcm and harness into my car, so I can use an hpp3 to tweak it.

I've been studying the pinouts on both cars, in the tech database. The changes seem to be very minimal. Looks like 3 new pins used on each bank. (there is some stuff not used anymore, but I don't think I care about the deletions - 9 pins - mostly iac and tps)

Trying to get a handle on the new pins... Would like to know if anyone can confirm, or add to, what I know so far.

The clear bank adds:
8 - Engine speed out
9 - Delivered torque out
24 - Cruise release signal

The blue bank adds:
14 - TAC serial data
70 - Theft deterrent fuel enable
71 - Requested torque input

I'm guessing that 71 is the gas pedal, and 9 is the electric throttle. (torque in, torque out)

What is 8? Another tach signal? What needs it? The cruise control unit possibly?

What is 14? What is TAC? What provides it or needs it? (sounds kind of like throttle actuate something or other...)

70 - fuel enable - unless I rewire the fuel relay, I can probably ignore this one? Because apparently my '98 didn't have an enable/disable.

Pin 24 - cruise release. My '98 doesn't have this pin. However, it did have 59 cruise engaged, and 72 cruise inhibit, both of which have been deleted in the '00. Am I going to have to convert over to a '00 cruise control box in order to have cruise with this pcm?

[Seppo Kaitainen]

I think you would be better off shelling out the cash for some mail-order tuning.

[John_D.]

Why is that? tell me more... [img]smile.gif[/img]

[Magnus]

EVAP is different. Fuel level sensor is different, your gauges won't read correctly in that sense.

Also, you have calbe throtle, using an electronic throttle PCM may cause disasterous results.

I don't even think its something to be considered.

[John_D.]

I thought evap changed from '97 to '98. That was what you were upgrading to, block-wise, if I remember right.

I have supersix 99+ intakes and tb sitting in the garage. Tom wanted another 250 to do my upper. Not a bad price, but I have a 99+ ported already sitting there...

[John_D.]

So if I go into the tank later to do a walbro/racetronix, and swap in a 99+ fuel level sensor, I would be ok? The pcm and sensor would talk ok then, and the gauge wouldn't care...?

And my '98 v8 cluster is another variable... It would read the fuel correctly, if the sensor and pcm were matched?

[AllTheGoodNamesAreGone]

man.. did you read any of dominics posts about hpp3? IMO its a waste of time/money..

[Magnus]

yea, if you are doing all this for hpp3 you are CRAZY.. its such a POS.

98 has metal tank.. 99+ has the plastic tank setup.

You have to switch to the 99 fuel level sender.

Oh yea, you also have to switch to a 99+ dash cluster.

i'm telling you dude, its not worth it at all.. keep your stock wiring harness.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by AllTheGoodNamesAreGone:
man.. did you read any of dominics posts about hpp3? IMO its a waste of time/money..<hr></blockquote>

Yep, his initial posts praised the unit, in terms in sotp feel.

His later posts were focused primarily on the inability to raise the rev limiter on a manual trans car. The auto trans seem to be ok though.

He also had problems with the coolant temp @ 160, which seems to be a problem with 01-02, but not '00. I'm getting an '00, so I should be ok there too.

So I'll be able to do speed limiter, rev limiter, shift points, different size tires, different gears, shift firmness. And I can play with the numbers rather than have to send the pcm off if I want to do something different.

Not timing though, because I'll still be running nitrous. That's ok, because I have a ver 6.1 maft+ for that.

Jason McCallister had good results with his '00 automatic.

[ August 08, 2003: Message edited by: John_D. ]</p>

[John_D.]

<blockquote>quote:</font><hr>Originally posted by Magnus:
yea, if you are doing all this for hpp3 you are CRAZY.. its such a POS.

98 has metal tank.. 99+ has the plastic tank setup.

You have to switch to the 99 fuel level sender.

Oh yea, you also have to switch to a 99+ dash cluster.<hr></blockquote>

Well, yeah, I am crazy. The 150hp nitrous shot proved that. :D

So just for grins, let's assume I'm going through with this after all. Let's work on what has to change. Are there any show-stoppers I haven't covered?

What happens if I don't change the fuel level sender initially? Nothing will "fry" will it? I can always just be sure to gas up every 200 miles or so. Until I get into the tank for a different fuel pump later on.

I don't understand yet about the 99 cluster. I just got a 98 cluster with the 150mph speedo. (not installed yet) What won't work? Will anything "fry" if I use it anyway?

I keep thinking if those 6 added pins are the only real change, it can't be that hard...

Maybe there are other changes not listed on the pinout chart? I'm trusting the pinout chart to be complete.
IF THIS IS NOT THE CASE let me know! [img]smile.gif[/img]
Thanks!

[AllTheGoodNamesAreGone]

you are friggin' nuts..

but if you are really bent on doing it.. i say go for it.. I will never understand it but.. do what you want..

just remeber james first rule of nitrous..
hpp3+no2 =&gt; boom

[ August 08, 2003: Message edited by: AllTheGoodNamesAreGone ]</p>

[nino]

john, if you dont need the pcm/harness just let me know. give me the word and i will ship it out tomorrow/or not. your call.

and yes, john d is CRAAAAAZZZYYYY. he has some mad plans yo! john if you lived here in san anto i would be either right along side of ya, or telling you to do a swap. good luck brother.

[ August 08, 2003: Message edited by: nino ]</p>

[slacker69]

I would say you are wasteing your money i would just send you pcm off to zoomer or intense-racing to get programed for what ever you want only cost like 350-400 bucks compared to what your are talking about doing will be cheaper. They can do everything the HPP3 can do and much more you can tell them what shift points you want and gear change and remove speed limiter as well as advance or retard timing

[merlinsrealm]

Listen to magnus and the others. I Swapped out my 99 for 01 PCM but even after all the homework I did and everything being the same I still had an altenator issue after the swap. With your 98 there are just too many varibles to consider and or change. Just get your 98 PCM reprogrammed.

Eric

[John_D.]

<blockquote>quote:</font><hr>Originally posted by merlinsrealm:
...had an altenator issue after the swap.<hr></blockquote>


I am listening. But still thinking...


Talk to me about this alternator issue. What happened?