can't read or write to vcm pleas help
can't read or write to vcm pleas help I recently purchased hp tuners about 3 months ago and since then have decided to do a 2000 ls1 swap into a 97 gmc sonoma. Some how during the wiring process I have gotten the engine to run but only for a brief sec or two without the removal of vats. So I decided to remove vats and when connecting to my data port I sometimes can make a connection and other times it just doesn't work. The furthest I have made it is to get my vcm id. Then if I attempt to read the vcm I either get an error no data cable check switch..... or it goes to timeut after saying something about delay not extinguished or something like that. Is there a problem with my engine wiring harness or my cable? Possibly something with my computer? I also was able to connect and get my dtc's which includes P1626 - Theft Deterrent Fuel Enable Signal Not Received (Pending) (OLD) (History) (Current) (Immature) I am really unsure what to do with this theft detterent fuel enable wire because my fuel pump functions as it should. Any help would be greatly appreciated.
Thanks,
..RJ..
Wade's Speed and Sport Center
171 Bustleburg Rd.
Rockbridge Baths Va, 24473
(540) 348-5144
Thanks,
..RJ..
Wade's Speed and Sport Center
171 Bustleburg Rd.
Rockbridge Baths Va, 24473
(540) 348-5144
ok, that is definatly the vats system.
You need to check a couple of things.
One being that you have a good connection from the serial data obd2 wire comming from the pin 58 of your blue connector all the way to your diagnostic port. You can do that with a ohm meter,
Then you need to check and make sure that you are getting 12volts to the obd2 port also, It should have 12v even when the ignition is off..
Then you need to make sure that you have a good ground from the chassis to the two grounds on the diagnostic port. and then if that still dont work, ground the shell of the computer to the car frame and try that.
If that dont work, send me your computer and ill fix it for free so it will take flashes. Thanks JEs
You need to check a couple of things.
One being that you have a good connection from the serial data obd2 wire comming from the pin 58 of your blue connector all the way to your diagnostic port. You can do that with a ohm meter,
Then you need to check and make sure that you are getting 12volts to the obd2 port also, It should have 12v even when the ignition is off..
Then you need to make sure that you have a good ground from the chassis to the two grounds on the diagnostic port. and then if that still dont work, ground the shell of the computer to the car frame and try that.
If that dont work, send me your computer and ill fix it for free so it will take flashes. Thanks JEs
ok so I tied all of this except grounding the case to the chassis. Still doesn't work all I get is the same error. So I tried somethin differnt. I turned the high speed communication off and now I can read the vcm but still can't write to it.it keeps giving me an message at eh bottom about something with normal connection failed then slow connection then it says timed out. I really am lost because it starts to write to the vcm after clearing it but never finishes. Also why doesn't the faster connection work? I really don't think that it is the computer either reason being I had another one plugged it up and the same thing happens. Also my pc gives me the no connection is the key on run error about every other time so I cut the key off then back on and it works fine for a bit. Oh yeah sometimes the vcm flash thing says that my vcm power is 0.0 or 0.1 volts. but I have like 12.4 volts on the pcm power wire. Who knows All I know is I have 12 days including today to get this thing done and I'm not so sure its going to happen anymore. Anyways SORRY for the neverending thread just thought that more info would be better then less. thanks again
..RJ..
..RJ..
first off go back to the other pcm you have cause in my experiences when the cable shows 0.1 volt you have deleted the ecm and there is nothing on it. i have been having some similar probs but randomly. i can read and write but sometimes my hptuners will get a error and i will loose the vcm cal and then i have to pull the pcm and do some off board programming at work(i work at a gm dealer) when this happens my vcm voltage shows 0.1 and sometimes 12.1 . sorry i cant be of more help. when a p1626 sets there is a 3 min time out that you have to wait for in order to start the car again. i will try and post more later
