VATS Thread

[Caleditor]

This is a PassLock that is also Serial Data instead of Circuit 229 or PWM

This is 100% OE Olds Intrigue with PassLock. The Fuel Enable password is sent over the Class II serial data line


I will post up a 100% OE Grand Prix PassLock that has a 229 PWM fuel enable circuit in the morning

[Caleditor]

We also know that the RPM enable parameter is at 0007C962. This is at line 00000030 in the other pictures. We also know that we have a timer setting some place. I need to find it in my information. We also know that the LS1/GEN3 512kb PCM's have 20 parameters. All we have between TC, TT, and DHP is 4 paremeters

[Caleditor]

This is an example of some is the bad information that has been posted in the past.

I have turned off hundreds of PassLock systems on V6 cars. Yes Hundreds. I work at a GM dealership and have been asked to disable a lot of them that come in for repeat PassLock sensors failures. We also have a Buy Here Pay Here (BHPH) department and when they have a failure they won't then turned off and not fixed.

I had a 2003 Impala 3.4L come in (towed in). It was a BHPB vehicle. I was asked to turn off the VATS.

This is how it was from the factory





I did what I have done what works for me most of the time.
I left the type on 1 --> set the injector time to 0 --> set the DTC's to X type

The car got towed back in just over 2 months later

I then set the type to 0 and let it go.

The car got towed back in 8 months later. Come to find out the car would not CRANK when the issue was present.

Guess what GM did. Some PassLock vehicles also have PCM controlled starters. This is one of them and when the PassLock sensor fails the PCM will not allow the car to crank.

I set the Type to #2. I have tried 2 in the past, but the vehicles would start and run poorly, maybe on 3 cylinders. That was not the case on this vehicle

Well it has been about 6 months and the car has not returned yet


Just a little more to think about. The VATS Starter Enable is also in that part of the code

[EagleMark]

We also know that the RPM enable parameter is at 0007C962. This is at line 00000030 in the other pictures. We also know that we have a timer setting some place. I need to find it in my information. We also know that the LS1/GEN3 512kb PCM's have 20 parameters. All we have between TC, TT, and DHP is 4 paremeters

There's a lot of things that have been found and documented in some of our old dissasemblies so I added them to the definition and have never used them. Sometimes it's better to not have them and confuse people or let them make adjustments not needed that cause issues.

All the LT1 of 94-95 era have VATS which disables fuel. Seems most also have a Starter relay tied into VATS, VATS Fail and no crank as well. The 9C1 Police car has VATS but no starter relay!

[lionelhutz]

You seem to be comparing a lot of different systems, which obviously won't be the same, so I'm not sure what you're tying to find by comparing them.

I'd think all the '98 MY you mentioned but the F-Body have a theft deterrent module controlling the starter interlock (when it exists) as well as the security light and also sending a PWM signal to the PCM. The Intrigue oddly enough has a starter enable output from the PCM that goes to the TDM which then controls the relay. The F-body has a BCM controlling the security light and starter interlock relay with a PWM signal to the PCM. The '98 Corvette is similar but has a serial enable signal instead of the PWM signal. Then, you get into the newer vehicles with the BCM creating a serial VATS signal to the PCM which controls the starter interlock relay. I'm not sure what controls the security light in these systems since it's often run from the serial bus so either the BCM or the PCM could signal it to turn on.

[kur4o]

The test for properly disabled vats will be to start the engine with bcm disconnected.

From what i found out there is two different Fuel enable signal

Digital signal send over class 2 serial network from bcm to pcm.
Analog Pwm signal send over single wire from bcm or theft modul to pcm.

In the software settings there is switch to tell which system the pcm will use

set to 0 is analog pwm system
set to 1 is class2 serial network system


In class2 serial system it is not only the fuel enable password, every 2 seconds the bcm send message to pcm that is online. if that messge is not recieved the engine will not start even with disabled dtc-s

[Caleditor]

I have seen a few time that changing the settings to something that has worked in the past --> the car will start and idle, but it runs like crap. Possibly cylinders shut off

[Caleditor]

look at the light grey bar on the link

http://www.pdqforensics.com/learning.htm

[steveo]

The F-body has a BCM controlling the security light and starter interlock relay with a PWM signal to the PCM.

94-95 had a seperate theft deterrant module and a starter enable relay

then in 96-97 they went to a bcm, but the starter enable relay appears to be built into that box (they kept that with LS1 f-bodies afaik)

[lionelhutz]

Yes, Steve, the small part of my reply you quoted came from a paragraph describing the different 98 model year theft systems and the F-body was a BCM with a PWM signal and an output that controls the starter inhibit relay in '98.

[Caleditor]

All of the RWD vehicles are straight forward. The issue is with the FWD cars.

I feel that all of the VATS should be in one thread

[Caleditor]

VTD CONFIGURATION	Unitless Number Value	This is used to activate the different VTD functionalities within the PCM.
VTD FAIL ENABLED BYPASS	Switch On or Off	Enables or disables the theft Fail-Enabled mode. Thiscapability is required for export vehicles.
VTD DIAG ENABLED	Switch On or Off	TRUE indicates the diagnostic is enabled and VTD failure is reported via Class 2.
VTD BAD PASSWORD	SHORTCARD	Threshold to compare against the Bad Password Counter during certain decision states.
VTD LEARNED ENOUGH	SHORTCARD	Threshold to compare against the Auto Learn Counter during Auto-Learn state.
VTD LEARNED PASSWORD	SHORTCARD	Threshold to compare against the Identical Password Counter during Learn Password state.
VTD DISABLE TIME	Seconds	Expiration time for the Fuel Disable Timer duringFuel Disable Lockout state.
VTD AUTO LEARN	Seconds_L	Expiration time for the Auto Learn Timer duringAuto-Learn Pending state.
VTD Class 2 INIT	Seconds	Expiration time for the PCM Class 2 Init Timer duringIgnition 1 Off and Powerup Transitions.
VTD Class 2 AUTO LEARN	Seconds_L	Expiration time for the Class 2 Auto Learn Timer duringAuto-Learn and Auto-Learn Pending states.
VTD PWM MAX ALLOWED FREQ	Hertz	Maximum allowable frequency for new vehicle antitheft pulse.
VTD PWM MIN ALLOWED FREQ	Hertz	Minimum allowable frequency for new vehicle antitheft pulse.
VTD PWM CONSEC READS to PASS	SHORTCARD	Number of consecutive good reads of pulse frequency requiredbefore setting VTD PWM Got Correct Frequency = TRUE.
VTD PWM TIME TO FAIL ENABLE	SHORTCARD	Threshold of the number of bad reads of pulse frequency thatare allowed before setting the VTD Fail Enable flag.
VTD PWM LO VOLTS LIMIT	Volts
VTD PWM LO VOLTS ADDTNL TIME	Seconds	Time added to VTD PWM Decision Point Time under low voltage conditions when deciding the fuel disable point.
VTD TIME TO IGNITION OFF	Seconds	The amount of time the ignition is off before the VTD logic performs powerdown state transitions.
VTD FUEL OFF TIME	Seconds	Expiration time for the Fuel Disable Timer during Fuel Disable Lockout state.
VTD PWM SIGNAL SAMPLE PERIOD	SHORTCARD	Lower threshold of valid signal sample period when determining if a correct frequency has been received.
VTD PWM VALID PULSE PERCENT	Percent	Lower threshold of valid pulse percent when determining if a correct frequency has been received.
VTD TIME TO DISABLE POINT	Seconds	Initial expiration time for the VTD PWM Decision Point Timer when deciding the fuel disable point.
VTD Class 2 NOT AN EXPORT VEHICLE	Switch On or Off	Used to turn On/Off the VTD Class 2 auto learning function.

Dirt old 512kb 0411 type VTD parameters from previous thread on disassembly of the code