Eliminating/bypassing Passlock

[Kardain]

I'm in the process of putting a 3400 in a 97 Sunfire (a popular swap of late) and a thought has crossed my mind that could be a severe hangup to completing it... the Passlock system

In my Sunfire, the Passlock system gets the code from the instrument cluster, not a BCM. Is there a way, using the DHP software or similar to have the Passlock disabled

[keitholivier]

How does the system work on the car from which you are using the PCM ? If the PCM recieves a password from the BCM in the original application (Serial link) then you are probably screwed. I have thought about this, since I am doing a conversion to put a 3400 engine in a Toyota motorhome.

The engine is out of a 2004 Montana. I was going to "convert" the engine back to the 97 level to fit in my wifes Venture. Even the venture has the BCM which communicates with the PCM via serial link. Cut a long story short, I decided to trash the venture and put the motor into the motorhome instead. I do have the complete working system in the venture. I thought I could maybe hook up a storage scope to the BMC PCM and "snoop on the communications during startup (to identify what code is exchanged. Then do some research and build a GAL based board that did nothing else but transmitted the password to the PCM on sartup.

The problem is that it would probably be less expense and less trouble overall to simply go the megasquirt route. Just the connectors and pins for my stopgap 95 Camaro PCM set me back nearly $200 and I still have to buy wire and connectors for all the sensors and other hookups. In my case I went with the Camaro PCM because it will control my transmission (4L60E) and there is no inexpensive solution for that problem ($700 for a tranny controller ?).

Are you sure the PCM needs a serial password or does it recieve the 30hz or 50hz squarewave signal from the enti theft module ? This is how the Camaro PCM works (there was no BCM in that car) and a $30 module provides the needed square wave signal. Its so small I think I can solder it diectly into the PCM housing.

Good luck
Keith

[Kardain]

I'd go w/ Megasquirt, but this car still needs to be able to pass emissions (meaning, they jack into the OBDII port).

The following components contain codes or passwords, or must learn codes or passwords for the Passlock™ System to allow the vehicle to start:

The ignition lock cylinder case
The body control module (BCM)
The powertrain control module (PCM)

So, it does use the BCM, but there should be some sort of switch in the PCM to turn it off.... or if not, which wires exactly in the BCM control the Passlock? As much as I don't want to, I am willing to splice in more wires...

The transplant vehicle has, in simplified terms, the magnetic ring in the ign switch to the instrument cluster, to the PCM. No BCM, no class 2.

[keitholivier]

Exactly what make model and year car did you pull the PCM from to power the 3400 engine ?

[Kardain]

1999 GAGT

[keitholivier]

This is a post from another forum:

http://www.3800pro.com/forum/archive/index.php?t-704.html

"I had the same problem with my swap using a 1999 PCM and instead of screwing around with BCM's and Class 2 data signals, I got a 1998 PCM, which still uses the Passkey theft system. I had to change the positions of the wires on the PCM connectors, but it works. Let me know if you need the connector views."

More on the Passlock 1 system:

http://directechs.com/guides/manuals/ig/accessories/N555L_7-02B.pdf

It confirms what I said regarding the PCM being enabled by a serially transmitted code. From what I have heard, what you need is a 98 PCM since those were the last passkey units that are easily worked around.

sorry it is not better news.... Normally, no-one will sell you a PCM with the security disabled, since it can be used for stealing cars (unlikely but possible). I work in The automotive industry and even our test engines get suplied often with most of the vehicle harness and modules since the developers don't want to send us "open" PCM's.

[keitholivier]

just for info, the emissions test doesn't require an OBD connector. That is only there for diagnostics if something doesn't work out (error codes stc). There are people using the megasquirt who pass emissions testing in CA simply by changing the tuning parameters a little (if you use a wideband O2 sensor its really neat for programming). Normally the emissions test a consumer is subjected to is not in any way comparable to the tests required of the OE's. All that is checked for you would be CO and HC's. More than likely no NOx measurement at all.

[Kardain]

"It confirms what I said regarding the PCM being enabled by a serially transmitted code. From what I have heard, what you need is a 98 PCM since those were the last passkey units that are easily worked around."

Well, that wasn't the answer I was looking for.... but what the hey. Can't win 'em all.

Guess I'll have to fiddle around with the class 2 stuff to get it going. Don't really want to spend the cash again for another PCM and reflash. (I'm on my third PCM purchase at the moment)

As far as emissions go, here they do the OBD port and sniffer tests... at least the last time the car got tested thats what was done

[Kardain]

Or... because I often don't know the full terminology of things:

http://www.hptuners.com/forum/showthread.php?t=12399&highlight=pwm

To disable VATS you must do the following:

1. Set the VATS value to "PWM"
2. Set DTC P1626 to "3 - No Error Reported"
3. Set DTC P1629 to "3 - No Error Reported"

[keitholivier]

Your PCM is not VATS. VATS predates Passkey and Passlock.

To use your PCM you would have to buy a BCM. A GM dealer would have to re-program one of the 2 modules so that the expected and delivered passwords matched. Since Passlock 1 uses a resistance scheme similar to Passkey but without the key, you may work out a way to get the BCM to think you have the right resistor (its 1 of 16 possibilities). But you will have to fulfill all of the shenanigans the BCM wants to see to convince it that the car is not being stolen and that no mission critical parts are non functional (don't know how the BCM reacts to missing modules).

Between the cost of the BCM + the connectors + dealer reset of one or the other part + fooling with the BCM to get it to "behave", I think you have a lot of work cut out for you. More than likely, going with the 98 PCM will get you there sooner.

But each to his own...
Keith

[3100 MPFI]

I say get the 1998 PCM, a passkey2 module and relay, and wire everything up under the dash. That is what I am doing for the OBD2 swap into my 1988 Cutlass Supreme. I am wiring in the stock 1996 passkey2, and just putting it all under the dash.

keitholivier, here in Texas, if you have OBD2, (1996+) then they connect your car to the ALDL when you go in for the emissions testing If you have ANY codes, you automatically fail emissions tesing.

The aldl test is required on all cars. Any codes means you fail.

[keitholivier]

Taylor

Sorry to hear about your test procedure.

I have to wonder if it were feasible to keep the cars default PCM and run enough signals to it so that it "thought" it was still running the engine. If one could achieve that, then one could let it sit there for hooking into when it is time to do emissions testing. One would have to work at it with a "stimulator" to find out what was needed to prevent it faulting out.

An idea would be to build a board that basically let the engine believe it was idling all the time (I think that is one "open loop" mode that is not a fault). Or alternatively WOT condition where the PCM essentially ignores the O2 sensor values. Then tie the O2 sensor signals to the correct fixed value.

I'm sure is would be quite complicated (in my case with a 95 PCM with a megasquirt "piggy backed" I could care less about any fault codes unless they impact the way the transmission shifts). But may be a way around the problem and less complicated that trying to work around the later passlock system. For me at least thats proved too much to deal with.

[3100 MPFI]

What I am doing to get around this is just converting the entire car to OBD2. I am also not adding in the second O2 sensor. I am just going to get an emulator for it. The only way I will add the second O2 is if I have problems with it passing emissions.

That way, there is no fooling the computer, or doubling the wiring. It is pretty straightforward, and not as much wiring as I thought it was going to be.

So far, to use the 1996 engine firewall connector on my 1988 interior connector (C100) I only have ot make 4 new grounds (they were grounds in the engine compartment that are not on the interoir), not using 2 more wires, and I have to run 2 battery wires.

I also have to add a 5 amp fuse for the passkey, but that is easy.

[Kardain]

To use your PCM you would have to buy a BCM. A GM dealer would have to re-program one of the 2 modules so that the expected and delivered passwords matched. Since Passlock 1 uses a resistance scheme similar to Passkey but without the key, you may work out a way to get the BCM to think you have the right resistor (its 1 of 16 possibilities). But you will have to fulfill all of the shenanigans the BCM wants to see to convince it that the car is not being stolen and that no mission critical parts are non functional (don't know how the BCM reacts to missing modules).

I know of a guy that swapped a 3400 into a 2000+ Cav, no need to get a reflash on the BCM, just the relearn procedure. The particular PCM that I have has not yet seen 12v+ since I had it flashed to remove the auto-trans stuff (meaning that's not getting touched by GM, and I'd have to purchase, flash and tune a 98 PCM). If I were to get a matching year/model BCM, hook up the following wires:

C2-A6, Magnetic Rotation Detection Sensor Return
C2-B4, Magnetic Rotation Detection Sensor Signal
C3-A10, Ground-Clean
C3-B2, Serial Data Signal, Class B, 10400 Baud (Primary)
C3-B4, Magnetic Rotation Detection Ignition Key Cylinder Sensor Feed 12 Volt Reference

Follow the standard relearn, in theory, would that work?

[keitholivier]

The difference between you and your friend is that he started out with a working Passlock type system with the requisite BCM, wiring, key cylinder, hidden in harness resistance wire, serial comms etc. If GM offered the bigger engine in a similar model year vehicle, with the same transmission, it could be that his replacement PCM would be "plug and play" other than having to relearn a code (I believe the BCM doesn't have a relearn procedure ?)

You on the other hand do not have the BCM or the serial cabling or the matching modules, so there are many issues that will cause potential fault codes in your setup. Not only would you have to satisfy the PCM's needs, but more than likely have to install the BCM, cabling and figure how to hardwire the BCM to believe that life was good (if it is even possible, considering that many modules communicate status via the serial link and not with hardwire "handshakes").

If you were an electronics genius and could knock up a board in a weekend to communiate serial protocols to act as standin for the BCM, this would be no problem. But most of us mechanical types do not posess the skills or equipment to make something like that happen in a lifetime. (ever built your own computer or PIC controller ? I have known some junior level kids that have done that).

I have had my own personal run in with this probem and I lost. I bought an Ecotec engine from a 2003 Cavalier with only 20k miles for $350. I got with it the PCM, BCM, engine compartment harness, fusebox, dash harness, ignition switch and harness, guage cluster etc etc. I did not get the transmission switch or harness (auto) nor any of the other serial linked modules (brakes, air bags, lights etc). I never got that system to fire. I unravelled what seemed like 200ft of wiring and traced the connectors on the schematic diagrams, made crude switch boxes to try to simulate the shift lever position and any switches in the tranny. I don't know if I got something wrong in the ignition key switch / key detection side of things since I was mising a connector on that side, but I'm sure it would have been less trouble to assemble a well documented megasquirt system with only 20 wires to hook up.

I still have the engine. The engine was destined for a boat that I bought near Indy for $250 (including a trailer). The boat was an inboard/outboard configuration with no motor (froze and cracked everything). Meanwhile, while I'm procrastinating with the GM PCM the company in New Zealand that I was going to get a water cooled marine manifold from changed hands, relocated and dropped the manifold I wanted from their product line. Eventually my wife said that wtih 2 kayaks, 1 jon boat and a 16ft runabout that we had enough boats and we could retire the "project". For a change I agreed...... So I will have to find another project for that nice engine (maybe my garden tractor ???).

Best regards
Keith