jason440

hello .im new to this site. I have built a 69 firebird with a 2010 l/99 camaro engine and a 4l65e trans.. we used a stand alone wire harness supplied by swap specialties..i am having trouble getting a signal from the obd port.. i have checked all my sensors connections ..this is my first ls conversion so i have little knowledge when it comes to tracking down this problem...this is what i have done so far....changed the can wire [ tan /white ] from pin location 6..7..8..9..nothing???? i was told that the signal travels thru the tcm ??? could there be a problem with my tcm??? where do i start to track this problem down...any help would great!!
thanks.............jason

jason440

wow after 100 plus views and knowone has a clue where i should start looking?? i guess my first mistake was purchasing a swap specialties harness.. they have zero customer service...i was hoping someone on this site could give me a hand with this problem...i been building muscle cars for over 30+ years and after hundereds of builds im shure ill figure it out....

G Atsma

Dude, you were only on here for 2-1/2 hours before your second post, and in the middle of the night. Be a little more patient. Someone who knows, and will be awake, will give you an answer. Just hang on...

jason440

i guess you have point there [lol].... its just frustraiting.. its a well built car that runs. i just cant scan anything until i figure out whats going on.... ill be more patient....

2xLS1

iTrader: (25)

Just google ALDL Plug and look at the images for a list of pin assignments.

2ToeRacing

iTrader: (5)

Every time I go to check a vehicle and the obd2 port is dead I check if the cigarette lighter to see if it's working.If they both are out then I check the fuse. Not sure if that helps but.....

jason440

ok i looked up ALDL and most show a purple wire in pin location 2 and a tan in location 9...my is tan/white in location 8 and tan in location 14 with grounds 4/5 and power in 16..my question is ....did the locations and colors change with the gen 4 ecm's...a assume the ALDL plugs i was looking at where late 90's early 2000's....because i dont know what harness this was built from it's hard to say...i think its a modified is1/4l60e...would this make a difference since my combo is ls3/4l65e????????? thanks for any help on this subject!!!! p.s. the the ecm has its own power supply with one wire to key on...but i did check my fuses like 2toeracing suggested...

2xLS1

iTrader: (25)

It's not going to be a cig lighter fuse in a transplant with an aftermarket harness.

OP you need to be using Can+ and Can- This PDF has pin outs for the cab bus on the E38 ECM and and the T42 TCM. Buzz fron the ALDL to the ECM and TCM pins for continuity.

LilJayV10

iTrader: (39)

start with the basics. check your power and grounds at your DLC.

You won't be able to tell much with a DVOM on the BUS. You really need a scope for that.

jcvett56

Position 4,5 Ground (typically Black
Position 6 Can + (twisted pair typically Tan/Black or Maybe Tan/White in your harness)
Position 14 Can - (Tan)
Position 16 Battery (Orange)

Colors may vary between each harness manufacture. Good luck with it. Make sure you don't have Dakota Digital or anything else plugged into a Y adapter on the Diagnostic Port. That will create interference when using a scan tool. Depending on how the wiring was done the TCM, ECM, and/or diagnostic port could be mis-pinned creating interference as well.