Help! I've been having a problem with VATS for quite some time. It would trip intermittantly. I had it bypassed with 2 resistors, a 1000 and a 470 both 1/4 watt. It worked fine for about a year.

Now it started tripping again, so I measured the resistanse of the resistors, and they were 1458. My key is 1474. So I unbypassed it and it worked fine on the key again.

How close does it need to be for the decoder to accept it?

I went to radio shack today, and bought a 10 ohm resister, still 1/4 watt, to bypass it again and that brought it up to1468 ohms. But it tripped again. So I unbypassed it again, and it won't work now. It trips every time.

This sucks, I'm at my girlfriends house, working on both cars, and have to get home to go to work tomarrow, lol.

I've read many posts on vats, I know it disables the injectors, is there a way to enable them anyway?

The starter enable relay is no problem, I've got a bypass for that already, I didn't realize it disabled the injectors too.

Any suggestions?

89 T/A TBI

 

I'm thinking with the 3rd 1/4 watt resistor, it made it draw too much of a load, and hurt the passkey decoder module.

is that possible? and how do I check?

 

Did you remeber to block off the tabs again on the key otherwise it will doubble the value that is being read.

 

the leads were completely seperated for the resistors, and together for the key, it has now started for me twice, so I guess I didn't ruin the pass key decoder.

I found a guy in WV on ebay who is selling a bypass module on ebay. it's not just resistors, it actually sends the signal to the ecm that the passkey decoder is supposed to send.

When I get all the info together, I will post it for anyone else looking to bypass VATS

so it tripped, and wouldn't start about 4 or 5 times in a row, after I put it all back together, but now it started twice for me. Hopefully it starts again in the morning, so I can go to work, lol.

 

If you could burn chip, you could just turn it off and be done with it.

 

I remeber when my VATS would act up i got to stay at placesd for ever waiting for it to let me turn it on sometimes i was in area's that were not friendly. I was also late to work many many times because of it going off.

 

Actually it would cut it in half

If it's working with just the key again sometimes then I'd say you're contacts in the lock cylinder or the small wires going to it are intermittent and when it makes the module sees half the resistance it should and shuts you down. The vats module sends a 30Hz square wave to the ECM which in turn enables the injectors. Obviously installing a frequency generator isn't practical. (I'm guessing this is what the guy is selling on ebay? but I"ve never heard of it) Replacing the lock cylinder and key is really only about $60 from gmpartsdirect.com or if you know someone that canburn eeproms/mem-cals they could just delete it for you.

 

yeah, it genenrates the 30Hz freq. And it's cheaper then the $60 lock cylinder. I seperated the wires thet go up the column when I was using the resistors, so the lock cylinder was completely out of the loop, by using the key, I meant re connecting the wires the way they were supposed to be.

Here is the response I got from him:
"Our VATS will work with your 89 Trans but, because it is a 89-93, you may need the 30Hz version, do you have the ECM/PCM part number? If you are not sure which type you need we have the dual-frequency VATS bypass for $10 more that has both types of signals, all from one module. Our VATS will bypass your failing decoder module but if it also prevented cranking you will also need to find and bypass/jumper the crank-disable relay."

it's ebay item # 7961506460

Thanks guys, when I get it, and put it in, I'll let you guys know how it works