djlunchbox

i can't pull any codes from it. ever... i tried 3 seperate scanners, no dice.
i have a brand new street and performance wiring harness as well.
the truck starts and runs , but i think it's been un openloop for over a year and a half now. i'm going to have a dyno tune (finally) in the spring, and i'd like to make sure this thing can be hooked up properly.

any ideas? the engine is a 95 lt1

firetird

i dont think your computer is shot, i think you need to get the correct scanner for it. It is not OBDII unless you converted it, but it does have the OBDII ALDL connector. I went through the same problem with my 95 t/a.

djlunchbox

i believe it has the obd1 connector on it. it's square (i think) not the trapizoid shape. how can i convert it so my auto x-ray will read it? it did work when i had the old wiring harness in the truck, but it was hacked to pieces and needed to be replaced. my scanner only works for obd1

blkchevyz

if it runs the computer work

i agree with the above post, sounds like your using an odb2 scanner on a obd1

djlunchbox

i wish i had some pics to show you. i know the scanner is an obd1, and i know it fits the connector on the new wiring harness. i think i had street and performance install an obd1 connector on the hew harness for that reason. it's jsut never worked. isn't there only like 2 wires the scanner neads to pull codes?

firetird

im pretty sure you can jumper a couple of pins and get your codes IF you have OBDI computer with OBDI connector. I believe the OBDII connector has 16 pins and is "D" shaped.

blkchevyz

if you got a multi meter see if the connections on the connector have continuity

Javier97Z28

that only applies to 93 ECM equipped cars.

djlunchbox

i have just about everything you'd ever need. lol. except time

what voltage should i be looking for off of what pins. 12v?


also, anyone know how to get the check engine light working?
when i was installing 2 of my guages in my dash, i jsut wired up a small check engine light next to my other indicator lights. i took the check engine lead off the new wiring harness, and wired the light inline from that to ground... (i think) i knew it probably wasn't going to work, because i thought you needed resistors in line or something like that. i'll be doing a custom dash anyways, so if you guys know how to wire it up so it will work outside of a factory guage cluster, then post up.


this is the only pics i have of the check engine light set up as it sits now.

96capricemgr

MANY manuals state that the jumper works on 94-5 but they are wrong. You need an OBD1 scanner with a display, most of us who are serious about DIY get a cheap laptop, cable and software. $100 for the laptop, $35-95 for a cable, 0-$100 for the software, will not fit a broad range of applications like a normal scanner but is unbeatable for the application is is meant for.

Dave89IROC

for the check engine light, you need the wire from the computer on one side, and 12v on the other, no resistors

as for your issues communicating, I'd say it is time to do some pinout tests on the harness(make sure the wires from the computer are going to the correct pins at the ALDL)

here, I just wired my truck, here are the pins


PCM connector D(blue) -------------- ALDL

20 ------------ B
30 ------------ M
**ground** ------------ A

*****make sure A is going to ground, it should be to the engine, but any good ground will work*****




these are the only pins needed at the ALDL for the PCM, however, you need the powers and grounds at the PCM for it to operate correctly

post if you need more pinouts

djlunchbox

wonderful, thanks so much, i can check it sometime this weekend hopefully and get it to work. NOW, if that is all correct, and i still can;t pull codes, then..... i guess i'll drive it to autozone and see if they can use the scanner there. i know mine works fine, i just used it on my 89 s-15..
unless it only reads to 94's or something like that. it DID work though , like i said, when i first bought the truck.