advanced wiring questions 98 vs 99+ (speartech, help please)
advanced wiring questions 98 vs 99+ (speartech, help please) Can somebody, who lets say, is crazy, (like myself) rewire a PCM from newer car, to a 1998 harness. I know the pinouts are different, but is the functionality of the computer totally different as well. Any main sensors that work differetly, I know the maf has a larger range on the 99+, but thats a benefit, i believe. More concerned with Crank position sensor, injector output, ect.
I know the 99+ has no wire for the temp gauge, but thats not a big deal i do not think.
I have not compared pinout for pinout, but anybody have a "ITS NOT POSSIBLE" and a reason why, before i waste my time looking into this.
Thanks.
Ryan.
I know the 99+ has no wire for the temp gauge, but thats not a big deal i do not think.
I have not compared pinout for pinout, but anybody have a "ITS NOT POSSIBLE" and a reason why, before i waste my time looking into this.
Thanks.
Ryan.
Re: advanced wiring questions 98 vs 99+ (speartech, help please) Yes you should be able to rewire the PCM. If you wire it up correctly, all your main engine management stuff should work.
If you retain your 98 engine/pcm/dash harness your coolant temp will still work on the dash, the 98 sensor is 3 wire where as the 99 is 2. On the 98, it just has an extra wire that has a dif signal that goes directly to your dash.
Your fuel level gauge will not work. The 98 has the 0-90 ohm gauge and the 99+ has the 40-240 ohm sender. The 98 gauge cluster requires a formatted signal from the PCM. The 99 cluster I'm not sure how it works, I don't recall but I know john posted about this before in one of my threads.
You might have some other misc fuling issues like tank pressure sender and EVAP. 98/99 have different tank/evap setups.
You will have to do a lot of tricky rewiring at the PCM harness.. might be easier to just buy a 99 harness/pcm combo. Easier, or perhaps more trusted.
If you retain your 98 engine/pcm/dash harness your coolant temp will still work on the dash, the 98 sensor is 3 wire where as the 99 is 2. On the 98, it just has an extra wire that has a dif signal that goes directly to your dash.
Your fuel level gauge will not work. The 98 has the 0-90 ohm gauge and the 99+ has the 40-240 ohm sender. The 98 gauge cluster requires a formatted signal from the PCM. The 99 cluster I'm not sure how it works, I don't recall but I know john posted about this before in one of my threads.
You might have some other misc fuling issues like tank pressure sender and EVAP. 98/99 have different tank/evap setups.
You will have to do a lot of tricky rewiring at the PCM harness.. might be easier to just buy a 99 harness/pcm combo. Easier, or perhaps more trusted.
Joined: Nov 2001
Posts: 1,707
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From: Anderson, Indiana
Re: advanced wiring questions 98 vs 99+ (speartech, help please) If I understand correctly, you want to rewire your 98 car to use the 99 and up PCM?
As far as engine function goes, it will work fine. I've done 3 of these, but they were swap related, so all of the vehicle details didn't matter.
I think you will have to change the instrument cluster to a 99^ also. 98 was the last year of the temp gage actually getting its signal from a sending unit. After that it is just a serial data feed from the PCM. This requires a serial data line being fed to the new instrument cluster instead of the sending unit wire.
As far as engine function goes, it will work fine. I've done 3 of these, but they were swap related, so all of the vehicle details didn't matter.
I think you will have to change the instrument cluster to a 99^ also. 98 was the last year of the temp gage actually getting its signal from a sending unit. After that it is just a serial data feed from the PCM. This requires a serial data line being fed to the new instrument cluster instead of the sending unit wire.
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91 Z28 LS2 408CI, LS9 Supercharger, LPE GT7 cam, Yank3000, 3450 raceweight.
Latest numbers: 9.71 ET, 141.42 MPH, 1.40 60' , 610 RWHP Mustang Dyno
www.speartech.com
91 Z28 LS2 408CI, LS9 Supercharger, LPE GT7 cam, Yank3000, 3450 raceweight.
Latest numbers: 9.71 ET, 141.42 MPH, 1.40 60' , 610 RWHP Mustang Dyno
www.speartech.com
