Figured I would do an actual write up on everything you will need and how to do it. This can be done easily in a day (assuming daylight). It took me about 10 hours as I spent quite a bit of time without daylight and using a flashlight.
DISCLAIMER!!!! This swap was done on a 95 Cutlass Supreme. It should apply to all 95 models and 94 as well. Double check your wiring!! I am not responsible for you not checking wiring and frying something. REMEMBER, I DID THIS ON A 95. THERE IS A CHANCE 94 C100 WIRING MIGHT BE DIFFERENT FROM 95. Although the diagrams I had showed no difference.
Items you need. Junkyard is your friend. I recommend getting all these items from the same car. 96 to 97 should all be the same, Not sure of 98-up parts
-Complete Engine Harness from C100 firewall connector, 96-97
-Highjack Pin J2 (purple) from the interior side of the C100 with a length of wire from donor
-OBD2 DLC with a length of wire
-Complete Injector Harness, 96-97
-PCM with PCM box and air tubes, 96-97
-Upper Intake Manifold w/ EGR and EGR tube to Manifold, 96-97
-Upstream O2 Sensor, 96-97+ (has square connector)
-Trans Selector Switch, 96-97
-Knock Sensor, 96-97
-3 wire coolant temp sensor, 96-up
-Intake Tube w/MAF sensor, 96-up (airbox not needed, they are the same)
-Downstream O2 sensor and harness
-EVAP Vent Solenoir/Purge Solenoid assy, 96-97
Take into account, this allows you to tune, so I skipped the downstream O2, EVAP system assy and UIM and EGR. They are to be deleted. More hassle than they are worth.
Modify the new harness like this.
Pin K1, splice a short length here and add to L1. Make a good connection as this is a large gauge wire. Highjack a spare pin/wire length off your original harness after you remove it or snip some from a junkyard car when you are there.
Move Pin E1 to A3
Pin J2 is the new Class 2 data wire. Add this to the vehicle side of the C100 and route it though to the interior. I did this, it takes a while to weasel the C100 out enough to add this wire without damaging it. Takes even longer to route it through. I went though the upper right of the C100 hole. Remove the airbag and glovebox so you can see it pop through. I used a thick 10ga wire to fish it though. I removed this pin and a length of wire from the Donor car to make life easy. Just plug it into the C100 and route it.
Remove old DLC (datalink connector) and splice new OBD2 DLC in. Tan to tan, splice both grounds from OBD2 DLC to existing (worked fine for me). Purple wire goes to Class 2 data wire from J2 C100 that you already routed. Then add the last wire to 12v+ source, constant. I just spliced into the first one I found
Remove these items, I tried to keep them in order of removal..
-Airbox, intake tube
-Washer tank
-Cross braces
-Battery
-Coolant overflow
-PCM and tray
-Unbolt C100 connector, T30 torx
-Remove Altenator for clearance if you want
-Unbolt P/S pump
Now start removing connector and undoing the harness clips
-Trans Selector Switch and Trans Main Connector
-Cruise control
-IAT should already be unplugged
-O2 sensor connector
-EGR
-MAP
-TPS
-IAC
-Coolant Temp Sensor (both 2 wire and single wire from rear of head, leave rear sensor in)
-DIS module connections (2 wire for rear crank sensor can stay plugged in)
-A/C Pressure switch near accumulator
-Grounds at trans/engine bolts
-Starter connections
-Cooling Fans
-Oil Pressure Switch
-Knock Sensor
-A/C compressor wiring
-Front Crank sensor connector near A/C compressor
-Cam sensor
-Get underneath and unplug low oil switch connector and follow it to the speed sensor connector. Unclip harness near speed sensor and unplug speed sensor
-On top, unplug 3 connectors that go to injector harness
-Alternator connections if not already done so
-EVAP Solenoid connector
-DIS connector on this side if not already done so
Now route the harness out. Passenger side fuse block and all. Everything should be unplugged at this point. Toss harness to the side. DONT THROW AWAY YET!!!
Now remove the UIM. Pretty simple here. Now unplug the injector harness and set aside. Install new injector harness. Be careful of routing, should follow how the original was except now the cam sensor runs though this harness. Remove original 2 wire coolant temp sensor and install 3 wire. Plug in.
Install UIM and TB. The P/S pump should be able to be bolted back in. If your changing to the new EGR system, install new EGR pipe and valve along with new UIM.
Remove knock sensor and install new one.
Remove Trans selector switch, install new one that the harness plugs directly into. 95 and earlier had a harness coming off of switch. Its easier to intall the new sensor than butcher your new harness up and wire to original
Install new O2 sensor. Easier to do it now with no harness in your way. Still a pain in the ass though.
If you are installing new EVAP assy, Do it now. You should have gotten the bracket and all. IMHO, this is a waste of time and money purchasing it.
Install downstream O2 sensor and harness. You will need to weld on a bung after the convertor. Much like the EVAP assy, waste of time and money IMHO.
Install new PCM box, bolts to holes already there. Route air tubes how they were on the donor car.
Route new harness. It will take some adjustments to get it just right. Once I had it roughly routed, I started plugging things in starting by the battery and adjusting harness as needed to fit right. Continue this until everything is plugged in and harness is secure.
Install PCM into box, plug PCM in (make sure you didnt lose the orange seals for the connectors) Snap on PCM box 'lid'
Plug in C100 connector and tighten it down. Re-install alternator at this time if you removed it for clearance.
Install new MAF and intake tube to the airbox.
Install the coolant overflow (tight fit, should work fine) and make sure fuse block is secured down, install crossbrace
On the inside of the vehicle, route the purple wire for the Class 2 data from the C100 firewall connector to the new OBD2 DLC as described above. At this point, all wiring should be complete
Install battery, washer tank, and intake tube/air box. Install crossbrace
Stand back, and make sure you plugged in everything. Odds are when you connected the battery, nothing went pop or smoked if you did everything right.
Turn ignition on, start car. Should start right up. Make sure car turns off and everything works as it should!!
If you got a scan tool, connect to DLC and make sure there is proper communication. If not, recheck wiring!
Oh, and I have to give some credit to Brian P for a little help with the wiring. At first I had the car running but wouldnt shut off. I had a switched ignition wire on a constant.Brian P saved me another hour of looking over wiring diagrams. Then again, I only spent under an hour with just the 95 and 97 C100 pinout diagrams to get that far
Originally Posted by White93z34
King of Code
