So I've tried to search this topic but I'm having difficulty finding what I need. I Bought a 98 z28 roller that I'm swapping my ls1/4l60e from my 00 z28. I have the 99+ pcm and harness but I'm looking for the best way to address the gauges. If I swap to the 99+ gauge cluster with the gauges work properly? What would have to be done to get the 98 cluster to work. Are there an other issues that I may be missing.. BCM? I know I have to make some changes to get the fuel level gauge to work so I'm not worried about that. Any advice would be much appreciated.

 

heres what i did... I bought a 98 roller, replaced the inside harness with a 99+, left the tank the same and changed a few things with hptuners to make it work witth the 98 tank. If you need that calibration stuff i have it. I also swapped the engine harness with a 99+... if you have and questions let me know...

 

PM coming your way.

 

bumping this up for a new issue. I have swapped the interior harness with a 99+ dash harness. Now the car wont start, turnover, nothing. I tried to hook up my hp tuners and it wont connect and the scanner say that the parameters are unsupported. Before the interior harness swap the car was running with the 0411pcm, 99+ interior harness, and the 98 dash harness. I swapped the interior harness to get the gauges to work. Ive checked all the fuses, VATS was disabled in the tune from frost, the VATS resistor mod was done to the car before i purchased it and was working before the dash harness swap. Now im at the point of parting everything out if i cant figure this out soon. Anyone have any ideas or suggestions? I really dont want to go through the hassle of putting the 98 dash harness back in if i dont have to. Ive checked everything i can think of, still nothing. PLEASE HELP!!!

 

I would double check all the +12V lines going to the PCM and put a volt meter on each one.
You can use something like a sewing needle to make contact with the connector pin on each wire. Just push it in a half inch next to the wire as it enters the big Blue connector.
411 Blue Connector:
19 - Ignition +12V (be sure it is on when starting too)
20 - Battery +12V
57 - Battery +12V
(hopefully I didn't miss any, let me know if I did and I will edit this post)

Next, put the volt meter on a few pink wires going to the coils and injectors. They should all be +12V when the ignition is on. I don't know how a Gen-4 key is wired, but I would verify that the coils and injectors (pink wires) have +12V when the starter is cranking.

Just my ideas, without knowing anything about the details of Gen-4 stock harnesses.

 

I will check those, but the motor doesn't even crank. I decided to part it out. **** this car.

 

IIRC you had another post talking about the missing/broken/burnt switch on the side of the trans. That switch mainly implements the Park/Neutral safety switch feature; the signal to the starter motor goes through it. It is cheap and easy to replace; while "unsafe" it can even be bypassed.

Hey it's your car and decision, but it could be just that one switch and perhaps a missing +12V to the PCM preventing your from having a running car.

 

nope. That wasn't me.

 

so i just checked my grounds on the pcm and blue pin 1 im not getting continuity to ground. I checked it at the connector on the passenger fender well and nothing there either. Would it be ok to run a separate wire straight to ground?

 

False alarm on the ground. i was on the wrong pin. grounds and the +12V at the pcm are good. My problem has to be something in the dash harness not matching up. when i turn the key on i get fuel pump priming, turn the key to start car and lights on dash go out and the little black box behind the radio clicks. So Im leaning towards VATS or the BCM. But why wouldnt i be able to connect my hptuners to the pcm through the OBD2 port?

 

SUCCESS!!! the theft deterrent relay wasn't sending the signal to the starter relay. i grounded the yellow/black wire at the starter relay under the hood and she fired up. Next is to check that my hp tuners is connecting to the PCM.

 

Another issue fixed!!!! I am able to connect to the PCM now. Turned out that the pinout on the C200 bulkhead connector is different from 98 to 99+. the wire for the serial data from the EBCM to the splice pack was swapped with somthing else. pulled the EBCM wire on the splice pack and viola. she is communicating now.

 

Glad to hear you are making progress!
Hopefully you are now happy you didn't part out the car.

 

Yea I am. Now I need to sell the car to pay for my turbo build on my 2000 z28.

 

I know it’s been a good while and hopefully you still have the answers or info for this .
i have a 98 T/A and want to do a 99+ ecm and harness but would like to keep my 98 cluster is this possible? Thanks

 

He hasn't been here since Oct 2017

 

You can just set the Tune right, I did it with a 1998 Camaro. Wire it right too.

 

so gauges can be made to work with a tune? how about the fuel sender if there is a difference there?