I bought a VATS bypass and wired it up today, no dice. When I rewired it back to the ignition, no start again. I should mention I did this without unplugging the batt. After fiddling w it and disconnecting the batt a few times, the key began working again. Any ideas what could have been happening??

 

What did you buy? Just a plug in dongle for 'CRANK'?

 

twas this one sir

 

If you know that your car wants/needs to see #2 then maybe the dongle is mispackaged. Check the dongle with a meter or if you wanted using the DIC and an FSM 8D section CCM check the A/D counts using the key, remove the key wait 10 minutes then check the A/D Counts using the dongle. When attempting to use the dongle does SECURITY go 'SOLID'?

You don't need to disconnect battery. KEY OFF and WAIT - theoretically 4 - 5 minutes but a longer wait could be considered a 'to do'!

 

Security is solid when attempting to crank w dongle.

 

If dongle reads #2 also it is possible that you did the key, removed the key then inserted the dongle and did another attempt to quickly! If it reads #2 maybe you just KEY OFF and WAIT!!

 

When I measured the key pellet the value was outside of #1 range but too low for #2. It was closer to #2 than #1 so I went with the 2. Most likely when I attempted the bypass module it was the incorrect resistance as indicated by solid security light. But I didn't wait the 5 min before trying again and that's why the key failed for a period of time. I guess it started working after enough time elapsed.

 

A #1 resistance hasn't been used since probably '88, maybe late '87. You can program a #1 but it's not done often.

You need to get a valid read on the key! How many keys do you have?

In the FSM see 8D-57 (DTC 51) The A/D Count values are listed there for a '96. Your FSM is .pdf so it should be on .pdf page 1255. Use the DIC for diagnostics get the A/D Counts.

***Drive by a GM dealer and ask that they 'drop' your key in their VATS Interrogator for a read maybe.

 

will do this today!

 

I bypassed the started enable solenoid by connecting with a large yellow heatshrink butt splice (and also labeled as a starter enable bypass for the next guy)... this should be an easy step to try.

Bypass means connecting the outside yellow heavy 10ga wire with the opposing side green/white stripe 10ga wire as it eliminates another failure mode (bad relay)... Note however, that with the stock ECU, this doesn't start the car, only operates the starter, as the ECU will look for a VATS input.

If you want to address that also, not sure what the ECU is looking for from the VATS, you can look into this, another strategy that addreses this is to re-flash the EPROM with VATS off. That doesn't do anything with the start enable not bypassed. I've installed a Holley HP ECU so I didn't have to address this.

The VATS bypass product replicates VATS key resistance only, good at eliminating VATS key requirement but if the system is faulty, it's not always the key or the contacts in the start switch. Of course it needs to be the correct resistance shown to the VATS module, you can easily make a pigtail with resistor to replicate if you know what the resistance is supposed to be. I have another VATS module with good known resistance I can provide for $20 of that helps... but if you're bypassing, bypass the relay also is a good idea. My relay on the older style interior was above the factory stereo location behind the center IP. Relay should have Yellow, Yellow, Green, Green/White wires.

 

Totally with you on this. I never splice into the harness, I always buy a new connector or use male spade terminals to plug into the harness connectors.

 

1. Properly crimped butt splice is the most reliable connection, it would have been just as easy to make a jumper, but this is 10 gauge wire with the relay/connector a potential issue.
2. Relay is only for lockout so it has zero use outside of the VATS.
3. it looks better behind the dash if you’re worried about the looks.
4. Point is to bypass the relay altogether, it can only do harm. it basically cuts your starter wire when the VATS says you're not ready. Zero negative impact on starter performance, possibly very good impact to starter performance taking a useless high current relay out of there.
5. Here’s a snapshot of your hole in the body panel ;-)

 

HAHA set my alarm off last night in the garage fixing the auto lock rod when I closed the passenger door locked and reached in with the door panel off and worked the lever by hand and HONK<HONK<HONK< until I had to unhook the horns, then I heard the ticking in the dash so I put the key in the pass door lock and turned it lock/unlock and the ticking quit and the security light went off and the car started right up later.

 

AZSP33D I just PM'ed you to clarify where you did this splice and asked a few more questions about this relay bypass. great info and I'm hoping to eliminate my relay as well.

 

 

Hey, Hate to chime in on your conversation but I have a question about the VATS also. My son purchased a 92 automatic vette for dirt cheap. The previous owner said the VATS went out and would not crank. He installed one of the bypass units and still no crank. My question is what do you do if the chip and the bypass are below any of the listings in the VATS chart. I checked the key and got 0.089. The bypass reads the same exact ohms. I thought maybe ECM because the fuse would blow every time the key was turned on. Sent the ECM off and was told it was bad so was repaired and returned. car still want crank but fuse does not blow now. He had a chip programed to delete the VATS but still no crank. When key is turned on the cooling fans come on but no fuel pump or injector power, just spins over.

Thanks.

 

If no crank did you bypass the starter enable relay ? No need to fuss with the passkey module if it’s tuned out of the ecms programming .

 

no crank but the engine turns over ??
in your diagnostic tests is the fp relay getting 2 second power from the ecm ?

 

Tunedport90, thanks for posting pic. just to be clear: i am removing the relay completely and just making a 10g jumper wire as pictured, plug into wire harness and this won't affect anything at all?

[In fact, it might fix my issue with the relay sticking and causing no start issue when vehicle has been run for over an hour. ]

 

Yes engine turns over just no start. Fuel pump does nothing, have gauge installed on fuel rail to verify. I did not check the FP relay but will do that soon. Tried starting it by running jumper wire to FP. still nothing with little over 40lbs of fuel pressure.

Thanks