Is it possible to get a 96-99 cavalier to run without the factory cluster? If you remove the cluster and do the relearn will it work (has anyone tried this)?
I ask because I gutted out the cluster from my 97 because it is only a parts car and I was using to cluster as a starting point for a fiberglass project, but now someone wants the engine out of that car and I can't start it because of the passlock. It started up once for a few seconds, then shut off, then would just crank but no start. I can use my other cluster and do the relearn, but that means I will have to keep the the cluster hidden somewhere once I make my new gauge setup, which I would rather not do.
D.Simoes wrote:Is it possible to get a 96-99 cavalier to run without the factory cluster?
No, it's not possible... unless you are somehow able to remove the Passlock coding from the PCM.. but I don't know of a way to do that.
Here's the official Passlock info from GM:
Quote:
VTD Class 2 Communications Description
The Passlock™ system requires the following components to communicate various functions in order to operate:
• The powertrain control module (PCM)
• The instrument cluster
The communication occurs over the UART serial data line, or CKT 800. Refer to Instrument Panel Cluster Microprocessor for an explanation of the operation of the UART.
Quote:
The powertrain control module (PCM) communicates with the instrument cluster using serial data over the UART serial data bus, CKT 800. When the instrument cluster determines a Pass Theft condition, the instrument cluster sends a coded password to the PCM. When the instrument cluster receives the correct password, the PCM enables the fuel injection system in order to allow the vehicle to operate normally. The PCM may allow the vehicle to start and stall quickly during a failed theft condition.
The PCM may enter tamper mode under the following 2 conditions:
• A bad timing cycle
• An incorrect password
If the instrument cluster does not send a password within a preset time window, the PCM will enter the Short Tamper Mode. During the Short Tamper Mode the PCM will not allow the car to operate for 4 seconds. If the password is incorrect, the PCM will enter the Long Tamper Mode. During the Long Tamper Mode the following actions will occur:
• The indicator will flash.
• The fuel injectors will shut off for approximately 10 minutes.
The vehicle may start, but the engine will quickly stall due to fuel cut-off.
The PCM will become fail-enabled under the following conditions:
• If there is a open in the serial data wire between the instrument cluster and the PCM
• If the vehicle is running
The following actions will then occur:
• The THEFT SYSTEM indicator will then illuminate continuously.
• The PCM will become fail-enabled for future ignition cycles.
If a failure in the serial data wire occurs under the following conditions, the engine will not start:
• The engine is not running.
• The PCM is not fail-enabled.
So the lock cylinder reads the resistance of the key... sends that "R-code" to the cluster (on a 95-99 J-body.. goes to the BCM on a 00-05 J-body).. then the cluster sends the fuel password to the PCM over the UART line. You could get the car to run without the lock cylinder (using a bypass module, or a resistor to the same resistance of the R-code.. if you can figure that out..)... but you still need the cluster and the PCM to make the car run.
You can run without a cluster on a 2000-05 model... but not a 97, sorry.
^thanks for the info. I'm not sure if hptuners can remove/disable passlock, but I am definetely not going to waste credits to register my parts car. Guess I'll just have to throw in my 99 cluster and do a relearn to test the engine.
After you initially start the car, then and only then you can yank the cluster. I'm not sure what kind of code the UART gives off to tell the PCM that all is well.
Lanman31337 - Cavfire wrote:After you initially start the car, then and only then you can yank the cluster. I'm not sure what kind of code the UART gives off to tell the PCM that all is well.
Wouldn't the car just fail to start next time?
What I was initially thinking was that maybe I could find the wires that the passlock uses and connect them to bypass where the cluster should be. Then do the relearn so that the car learns the new "password" is nothing. I think I'm still going to try this just for the hell of it. I don't think it will work, but if it does it would be interesting.
The Passlock wires from the lock cylinder to the cluster are on that 'other' connector at the top - with three wires. If you're bored, maybe try taking apart the cluster and see if there's a part of the circuit associated with the Passlock R-code and the feed to the UART wire on the other (main) cluster connector... if you can isolate that stuff and cut off the rest of the cluster... you're golden.
I don't have a 95-99 anymore to try with!
I have a 2000 sunfire and wanted to take the cluster out and make my own with autometers. Can I do that without any problems? Or will it affect other features?
Jack Fleming wrote:I have a 2000 sunfire and wanted to take the cluster out and make my own with autometers. Can I do that without any problems? Or will it affect other features?
Warning lights.
Some can easily be easily wired to leds, some need the cluster to function properly (such as abs, srs, cel and a few others I beleive). Obviously you could just choose not to keep the ones that wont work, or any of them for that matter. If you want to keep all of them working, the only way I can think of would be to relocate the factory cluster and wire the new warning lights right off the factory circuit board.
