LS1PHNX

My car has a basic tune from a local tuner here...i went back to get my car fully tuned because i changed my cam and added some bolt ons...however, he cant tune it because he doesnt receive a signal from my computer. He isnt able to edit anything! he cant even scan my car! so later today, i rented a scanner from autozone, and i was able to scan and read codes that my car was throwing!!!??? what could the problem be???

foff667

iTrader: (2)

Possible blown cig lighter fuse would be the first thing I'd check.

YellowToy/A

iTrader: (1)

Do you have some kind od scan gage?

Eurospec2

iTrader: (2)

If you can read the codes with the autozone scan tool, then its not the cigarette lighter fuse.

What year car/pcm are we talking about here, and what software is your tuner using?

edcmat-l1

iTrader: (10)

It can be that if the scanner has a battery pack. My Vetronix will connect to a car if the fuse is blown. Thats just there to power up the scanner.
That being said, I too would like to know the particulars. Like what does the scan tool say when it wont connect?

LS1PHNX

my car is a 1998 pontiac trans am...the software that he is using HP tuners....when i put the autozone rental scanner it reads code P0405-egr flow sensor (because i swapped to an LS6 Intake)....and it also reads random misfire due to the bigger cam....the scanner has its own battery pack

LS1PHNX

also my tuner was able to get into the computer when it was OFF the car...however he was able to when it was ON the car

Eurospec2

iTrader: (2)

Well, most likely then as Ed and Foff pointed out originally if the scanner does have a battery pack, and your tuner can read the PCM outside of the car, then i was probably incorrect and it very may well be your cigarette lighter fuse blown

1SIC_GM

It also could be if you have a system on your car...because it could have a loose ground some where in your wiring.All of that is going to your computer.

LS1PHNX

i checked all of my fuses and theyre ok....i do have a system in my car and im using my stock deck...

wrencher

iTrader: (2)

Check for power & ground at the 16 pin DLC.
That car should be J1850 VPW interface protocol
Look at these;
http://www.obd2.com/obdii_dlc_interfaces.htm
http://www.chevymania.com/tech/obdii.htm
serial data info class 2 would be relvant to you
http://www.gmtcny.com/serial%20data.html
Check that there is csome voltage there vararing on the communication line. But only do so with a 10 mega ohm impedance digital volt meter.

Bill Bowling

iTrader: (6)

Does your cig lighter work?

Bill

LS1PHNX

yeah i checked my cigarette lighter and it works....im still a little confused on why the autozone scanner can scan my car but my tuner isnt able to