OBD2 swap in older car

[3100 MPFI]

I decided to post a new thread about my OBD2 swap for my 1988 Cutlass Supreme.

Most people seem to be doing the OBD2 swap to like 1994-1995 cars that are already SFI, so the wiring is minimal at best. You have to add in some wires, but for a 1988 car, you have to rewire the whole car.

I figured I would show pics of mine seeing that I want to fully document this and for future refrence for those that might decide to do this to their 1988-1993 cars.

Well..... After I blew up the engine in my gold car (1988 Cutlass Supreme with the 3100 MPFI, 4T60-E), I have not been able to get it to run right after I fixed it. I have done everything that I can think of all to no avail. Time to pull out the big guns.

I am doing an OBD2 swap. I started it today. I started pulling the old wiring out, but the way it is twisted around in there, I think I am going to have to pull the engine out just to get the wiring out. No big deal seeing I have to pull the engine out anyways to swap out the tranny (replacing the 1993 4T60-E with my 1996 4T60-E).

I am going to have to do a lot of interior wiring as well. I have to add in the pass key shit, so since the dash has to come out, I am going to do some isolation and padding to help get rid of the squeeks and rattles.

I got about half of the wiring out today, but I think I have to start getting the engine apart to get the rest out. Seems to be routed under the engine, then next to the tranny. No biggie.

I am going to try to REALLY document this in case others decide to go the same route later on.

time for pics:

This is all of the new 1996 wiring pulled straight from my wrecked 1996 Grand Prix. It is all of it from the C100 firewall connector, to the passthrough under the brake booster. I also have both of the fuse blocks. I am not sure how extreme I am going to go with this, but in the worst case senario, I can go ALL OUT.



This is the new PCM and the 3100 ALT. I also have the spare ECM for my 1990 Grand Prix in there, but the silver one is what is going in my gold car.



This is all of the wiring out of the ECM area under the coolant resevoir. I removed the stock ECM holder seeing that I can't use it for the newer PCM. I will also have to try to use the newer COOLANT RESEVOIR.



More of the wiring coming out.



And last of all, these pics show why I don't like the OPTIMA BATTERIES. I had one EXPLODE in my car, and the dry cell shit in there caused this damage to the hood.



And if you look to the right of that big ratchet, you can see that the side is all flakey and messed up as well. I am going to have to get some paint on there before it starts to REALLY rust.

[3100 MPFI]

Got a lot more done today that I was expecting. At this time, all I have to do is remove the STARTER, CROSSOVER, FLEX PLATE BOLTES, MOTOR MOUNT NUTS, and the BELLHOUSING BOLTS, and the engine can come out.

I got the stock wiring out today. That is, I HOPE, the worst of it. I only had to cut 2 wires (for the pressure switch on the power steering rack).

I also comparted the 3 different alternators for my car. The one on the LEFT is the stock 3100SFI. The one in the MIDDLE is the 135-140 amp that I was using in the gold car. The one of the RIGHT is the stock 2.8/3.1.





Using an ENGINE TILTER tool, I was able to disconnect the exhaust downpipe from the TOP of the car. This is the main reason that I prefer using the 2000 Lumina 3100 rear exhaust manifold, and downpipe.




After 4 cuts, smashed knuckles, and countless obsenities, I FINALLY got the old harness out of the car. In all honesty, I did not have near as much trouble getting the new harness out of the pink car than this sumbitch gave me.



Here the car sits as it pretty much was when I left it. The only thing different is that I went ahead and took the crossover heatshield off, but I left the crossover on.



One thing about the pink car is that it had that weird canister purge. Does anyone know what the big deal was with it?






That is my pregress as of now. Tomorrow, I might try to get under it to get the rest undone, but I most likely will not be able to pull the engine until this weekend.

[3100 MPFI]

I was not able to do anything to my car this weekend due to family crap, but I got the engine out today.

Tomorrow, I am going to start pulling the dash and IP Carrier so that I can do the OBD2 swap the proper way, but for now, this is some real progress.

Now for the pics:







Now here is the pics of my $30,000 (THIRTY THOUSAND DOLLAR) engine hoist:







And here is the car sitting there with the engine out.





Here the engine sits waiting for me to swap the heads and cam



And a better pic of my GM oil cooler. The one that when the gasket blew out on it, it caused me to blow the engine up.



And here the car sits now. Just waiting for me to molest it even more:







That is my progress as of now.

[3100 MPFI]

I didn't get to do anything yesterday due to thunderstorms and laundry (as in, I needed to DO laundery anyways).

Today, I got the dash out, and pulled the wiring for the OBD2 conversion on the interior. I did not do any wiring because I did not have my books with me, so I will start that tomorrow.

The first thing I did today was start pulling the dash. About halfway through, I saw that I had been sitting literally 1 foot away from a wasp nest. Had to stop, run to the store to get the spray, and then get back too it.

Here is the dash and I P Carrier (Instument Panel Carrier) coming out:






And here is the OBD2 stuff that is going into the interior.



This is a closeup of the connectors of everything that is being added, or changed.

This is the C100 firewall connector. Most of the pins are being swapped out, instead of cut and soldered, so the wiring for this one is minimal.



This is the 1996 OBD2 ALDL connector. I figured that if I am going to do this, I might as well go all the way with it.



And these 3 connectors are for the PASSKEY II. The GREEN ONE is for the theft deterrent module. The big fat one is for the theftlock RELAY, and the small one is for the chip in the key.





more to come.

[3100 MPFI]

Thought I would do a minor writeup on the OBD2 C100 firewall connector wiring. all information was taken from a 1993 w-body service manual for the older wiring, and from a 1996 w-body service manual for the newer wiring.

comparing the 2 wiring diagrams:

16 WIRES ARE THE SAME
11 WIRES ARE ADDED
2 WIRES ARE REMOVED
7 WIRES ARE TOTALLY DIFFERENT

1 WIRE IS THE SAME FUNCTION, BUT A DIFFERENT COLOUR!

This is the basic wiring. The C100 connector only has 36 pin locations, but not all are used. The pins are wires:

A1-3
B1-3
C1-4
D1-5
E1-2
F1-2
G1-2
H1-5
J1-4
K1-3
L1-3

The wires that are the SAME are wires:

A1 - PNK/WHT - ingnition feed to stoplamp switch
A2 - GRAY - switched feed for fuel pump
B1 - RED - battery
C3 - LT GRN - PCM ac request
C4 - LT GRN - backup lights
D3 - YEL/BLK - low coolant indicator
D4 - WHITE - tach
D5 - LT GRN - trunk release
E2 - BROWN - volts indicator
F2 - TAN - oil pressure indicator
G2 - DK GRN - coolant temp indicator
H3 - BRN/WHT - MALFUNCTION indicator control
H4 - DK GRN - vss
J3 - PURPLE - stoplamp TC output to pcm
J4 - TAN - uart data
K1 - RED - battery


The wires that are added are wires:

B2 - WHITE - cruise control ENGAUGE to PCM
C1 - WHITE - magnasteer feed
D1 - DK BLU - fuel enable from passkey
D2 - WHITE - stop lamp signal to cruise
E1 - PINK - ignition feed to PCM
F1 - BRN/WHT - low oil level
G1 - BROWN - cruise control cutoff
H1 - GRY/BLK - cruise control resume
H2 - DK BLU - cruise control set
K3 - BROWN - magnasteer output
L2 - YELLOW - PNP output for theft relay


The 2 wires that are used in 1993, but not in 1996 are wires:

A3 - PINK - IGN 1 FEED
L1 - RED - BATTERY


The wires that are totally different are wires:

B3 (93) - YELLOW - IGN SWITCH START
B3 (96) - PURPLE - passkey output

C2 (93) - PNK/BLK - FUSED FEED TO ecm
C2 (96) - ORN/BLK - pnp signal

H5 (93) - WHITE - CRUISE INDICATOR CONTROL
H5 (96) - GRAY - cruise control on/off

J1 (93) - WHT/BLK - DATA LINK
J1 (96) - DK BLU - PNP output

J2 (93) - DK GRN - A/C COMPRESSOR CONTROL
J2 (96) - PURPLE - serial data

K2 (93) - ORANGE - IGN 1 FEED
K2 (96) - BROWN - fused feed to cruise

L3 (93) - RED - BATTERY
L3 (96) - PURPLE - fused feed to PNP switch


The wire that is the SAME, but has a different colour is wire:

J4 (93) - ORANGE - uart data
J4 (96) - TAN - uart data



hope some of you can use this in the future.

Taylor

[3100 MPFI]

Every day, I get a little more done. Today I was fighting the sun, and allergies, but I got about halfway done with the wiring. Tomorrow, I have to finish running the wires, and then do the soldering. Today, I just twisted the wires to hold them together, and then tomorrow I will solder everything after confirming that the connections are correct.

On to the pics:

I pulled all of the wires out of the 1996 C100 connector that are the same, so that I can just repin it and make it so that the wiring will be minimal.




Here it is about halfway through. I have to solder everything still, but it was around this point that I needed a break and started running the new wiring in the engine compartment.



Here is the wiring of the C100 connector almost finished. The only things that need to be done at this point are mostly for the Cruise Control. I think I am going to have to upgrade to the newer ELECTRONIC Cruise control seeing that the OBD2 PCM needs to get a signal from the cruise that the older vacuum cruise can not provide. If I don't use the newer cruise, then I might not have cruise at all, and with as much highway driving as I do, I REALLY need it.



These are all the wires that are left over in the original C100 connector. I have to fingure out what they are all for, and how to bypass them, or reuse them seeing that they are not used in the new connector.



And this is the engine compartment with the newer wiring going in, and the PCM box installed.









Let me know what you think.

[DEI37]

That looks like work, dude! Good work...hope it all goes well.

[3100 MPFI]

Thanks. It is all going slow, but it will be worth it in the end.

[3100 MPFI]

Well. The interior wiring is almost finished. All that I have left to do is to cap off, and remove the old CRUISE CONTROL wiring, I have to add a 5amp fuse for the theftlock, and then figure out what I am going to do about the wires that got their power, and ground from under the hood, that the new wiring does not use.

First of all, here is the OBD2 C100 connector properly wired up. the only 3 wires not hooked up are 1 for AIRBAGS (which I don't have), 1 for the THEFTLOCK (which I need to add a fuse for), and 1 for the AUTOMATIC DOOR LOCKS (which I am not going to put in seeing that if you leave it unhooked, then the doors will lock at 10 MPH instead of when you put it in gear).



Here is the C100 reconnected and in place. Now I just need to wrap up some loose ends, and get the dash back in.




These are the 8 wires that I have to figure out what I am going to do with. All 4 of the black ones are GROUNDS, so they are easy, but the double pink one is HOT IN RUN, the ORANGE, and both REDS are HOT AT ALL TIMES. I will deal with them later.




Let me know what you think.

[3100 MPFI]

I decided to go ahead and write up what I did with my C100 connector for the wires that are not the same.

This is what I did.

1993 C2 is moved to 1996 E1

1993 B3 YELLOW is run to THEFTLOCK relay, and PURPLE output from THEFTLOCK relay is run to B3

1993 J1 DATALINK (wht/blk) is moved to 1996 J2 SERIAL DATA (purple)

The wires that are no longer used on the 1993 wiring is A3 (double PINK), B2 BLACK, C1 BLACK, K2 ORANGE, K3 BLACK, L1 RED, L2 BLACK, and L3 RED.

All of the BLACK WIRES (B2, C1, K3, and L2) are all GROUNDS, so just create a new ground for them.



C1 - WHITE, and K3 – BROWN, I did not hook up. Those are for the MAGNASTEER (variable assist power steering), and are only controlled by the 1996 ABS EBCM.

I went ahead and rewired my CRUISE CONTROL to use the newer ELECTRONIC cruise control.

B2, I did not hook up. That is just a signal from the PCM to turn on a CLUSTER LIGHT that says CRUISE (BUICK).

D2 – white - stop lamp signal to cruise, I connected this to the HIGH MOUNT STOP LAMPS wire at the C202 connector (C202 – 4M – LIGHT BLUE)

G1 – BROWN – cruise control cutoff – I connected to WIRE G – BROWN/WHITE on the old CRUISE CONTROL module.

H1 – GRAY/BLK – cruise control resume – I connected to WIRE M – gray/blk on the Cruise control module

H2 – DK BLUE – Cruse control set – I connected to WIRE L – DK BLUE on cruise control module.

H5 – GRAY – Cruise control on/off – I connected to WIRE A – GRAY – on cruise control module

K2 – BROWN – fused feed to cruise control, I connected to the fuse block on the CLUSTER FUSE (pink/blk).




C2 – ORANGE/BLK – is the PARK NEUTRAL input to the CHIME MODULE for the automatic door locks. I did not connect this wire. If left unconnected, it changes the AUTO DOOR LOCK feature so that instead of locking the doors when you put it in gear, it now will lock them when you reach 10 MPH.

D1 – DK BLUE – is connected to the PASSKEY 2 module for the fuel enable signal.

F1 – BROWN/WHITE – is the LOW OIL LEVEL indicator for the 1992-1994 analog gauges cluster.

J1 – DK BLUE – is the SECOND GEAR START switch signal to the PCM.

L2 – YELLOW – is the park input signal for the theft deterrent relay.

L3 – PURPLE – is a DOUBLE wire. One is for the AIRBAGS (I left unconnected). The other goes to a 5 amp fuse, which you have to add. The other end of the 5 amp fuse is spliced into the THICK yellow wire for the Theftlock relay.



This should help some people that might go this route later on in life.

[3100 MPFI]

OBD2 swap in 1988 Cutlass Supreme

I didn't get a chace to get a lot done today, but the transmission is ready to come out. The only thing holding it in place is the jack underneath it. I was not able to get the transmission out or do a lot of wiring today. I want to get the engine compartment ready. Tomorrow I will try to get the tranny out, and then replace my steering rack. Once that is done, I will powerwash the engine compartment, and start putting everything back together.

I also need to rebuild the engine still, but that should only take me a day or two.

Anyways. Here is a pic of my baby. Doesn't she look pitiful?

[IsaacHayes]

You are crazy. Lots of work!! Going with DHP over burning your own chips and ostrich huh?

[3100 MPFI]

for now, I just want the car to run, and converting it to OBD2 is the fastest, and cheapest way to make it happen. Once I blew the old engine up, the new engine could not run without the high compressions. I don't know how you tune chips, and I cant get the car to Ben to be tuned, so I decided to do the OBD2 conversion seeing that I have a complete parts car sitting here.

So far, it has not been that bad. I did some research on those wires that I had left over, and it looks like the ORANGE, and PINK wires are not used anymore.

[3100 MPFI]

Weather has not been cooperating, and I have been feeling sick.

I finally got the car off of the ground today, but I was feeling bad, so I went home early. In only 15 minutes, I was covered with sweat and gasping for air.

pics

Funny thing was, when I was jacking up the drivers side, the back of the car was wanting to lift higher than the front. I think that was because the passenger side front was even lower than the drivers side. I had to lift the drivers side first. I could not get the jack under the passenger side.



Here you can see the drivers side back to normal. I just put the wheel back on it seeing that I left the axle in that side.



The passenger side was even lower, and I had to jack it back up further from the back. I did not have anything to get under it, so I ended up having to support the subframe with one of my twin cam heads. With the head under there, I could finally get my jack under it. Finally got some use out of that damn 3.4 DOHC.



After I got the car jacked back up, I just used a log to hold the weigt. I can't put the wheel on this side because the HUB, and AXLE are still out of it. This will work for now.



Finally, the car is level again.



If the weather is still good, I will do some more tomorrow. I STILL need to do the steering rack.

[3100 MPFI]

Got some done today. I got the steering rack swapped out, and tomorrow can get it finished bolting it in.

First of all, one of the power steering lines did not want to come off, so I just removed it with the rack, and will get it off tomorrow. I started losing patience with it, and it will be easier to do off the car.

Here is the empty engine compartment with EVERYTHING out that is coming out.



Here are the 2 racks side by side. The BLACK one is the old 2.75 FE3 rack (which has a bad leak from one of the seals), and the rusty looking one is the TGP 2.25 FE3 steering rack.


And here is the new rack back in with the mounting bolts finger tight.


Will get some more done tomorrow.