2.2K ohm 1/4 watt 5% carbon film resistor

 

Thank you

 

Also what wires do you put the resistor on

 

Resistor goes between connector C2 terminal A3 (yellow) to connector C2 terminal B5 (black/white stripe) ground then do the relearn procedure, this is outlined in the 7th Gen discussion or you can use the SEARCH function to find what you're looking for. I'd recommend reading up on this before doing the modifications or Passlock bypass.

Have you gone through and checked everything else like the starter relay? Bypassing the Passlock would be the very last act of desperation for me.

 

Yea the relay does click but it might not even be the passlock bc the message center on the cluster doesn’t work

 

If the relay clicks the computer is giving the okay to start, I'd look at the why the starter isn't working when the relay clicks

 

Si el relé hace clic, la computadora está dando el visto bueno para comenzar, vería por qué el motor de arranque no funciona cuando el relé hace clic.
[/COTIZAR]
, Estoy lidiando actualmente con este problema, lo he estado estudiando y he observado que este auto con problema de Passlock tiene dos condiciones, primero, luz security encendida da arranque pero no da marcha,por alguna razon, sea problema BCM, cableado, o cambio resistencia de campo magnetico de sensor efecto Hall por desgaste llave SW, y el segundo caso no hace nada, ni click en nada...cuando la PCM de tanto darle marcha y no encender motor, corta todo voltaje a BCM y a ella misma, esto requiere el reaprendizaje de la BCM tal como lo indica Hierbabuena algo mas arriba. Si logra obtener resultados agradeceriamos su publicacion para alimentar los aportes del Foro a sus miembros.

 

Does that "resistor fix" really work? I know I've run across posts on other Forums saying the problem returned for some people that implemented that.

I can say this about my 2002 Impala (bought new in 2002) : I was having this problem off and on when the wife was driving it. She'd call and say she was stuck, car wouldn't start. 10 minutes later, it started. The problem itself started about 5 years into ownership and I noted several occurrences of it. All the while, I researched fixes online, but decided not a single one of them definitively cured the problem.

Well, in 2011, when I bought the Equinox and the wife started driving that (and I started driving the Impala as a work commuter), the problem just stopped happening ... with no fix applied whatsoever!

Is this just dumb luck, or did it have something to do with how my wife drove the car (or something to do with her keychain)? I don't know ... but there has to be something to it. When I bought the Equinox in 2011, the Impala had 140,000+ miles on it. In another couple weeks, it'll hit 250,000 miles ... so it's not like the car's been sitting still...

 

Yes the resistor bypass does work but only to address issues with the ignition switch theftlock feature. It will not work for ECM to BCM VIN mismatch or other security features. A heavy keyring or fast turning of the ignition to start may cause contact bounce giving the BCM a false alarm and start lockout, a high miles ignition switch is going to have far more mechanical play and that contribute to the security faults as well. I have a 2003 9C3 issue LS (detective) and had to do the bypass, I soldered a 2.2K 1% resistor to the BCM pins and went thru the relearn procedure with no issues but I can't speak for the the Equanox or other models.
All the passkey data is stored in a protected area of the BCM ASIC and once written is locked, from my understanding when the key is in the ignition switch a wakeup is sent to the ASIC and a challenge is issued, this is what is used to verify the switch sequence for the passkey and a valid response sets the security flag to zero, the sequence basically gives a voltage return to the BCM and that's compared to the stored value in the almanac. The resistor bypass emulates a valid response giving a constant load across the pin to ground and a voltage that satisfies the challenge. I think this was in the order of 4.35 volts measured on a Keithley DVM. Once the challenge is done the BCM goes back to sleep and assumes the key is in the ignition and waits for the next command. The passkey system is only reactive, no errors no further actions and the challenge is made only when the request is made by insertion of the key that causes the correct closing of the security contacts inside the ignition switch, incorrect or no closure of the contacts equals zero output thus setting the security flag.
If the engine starts you can actually pull out the BCM completely and drive the car, no security flag was sent so it will restart without the BCM in place. If it locked out the starter then removing the BCM does nothing as the flag will remain until cleared by the BCM. Only the speedometer and tachometer will work without the BCM as this data is derived from the ECM hiding in the air filter box.

 

Yes the resistor bypass does work but only to address issues with the ignition switch theftlock feature. It will not work for ECM to BCM VIN mismatch or other security features. A heavy keyring or fast turning of the ignition to start may cause contact bounce giving the BCM a false alarm and start lockout, a high miles ignition switch is going to have far more mechanical play and that contribute to the security faults as well.

How do I know what the nature of my SECURITY message/lockout issue is (or was) with my Impala? The only symptoms were: "SECURITY" message in the DIC, and a no-start condition (for 10 minutes). I never installed the resistor bypass fix ... I never installed any fix ... and the problem went away on its own (12 years now, hasn't happened)! My Impala is all-original from the Factory, so there's no ECM to BCM VIN# mismatch issue. Have I just been lucky (for 12 years) ... or is there something else going on that's not completely understood about this problem? I think it's the latter. And speaking of "mechanical play in the Ignition" ... my ignition has even gotten to the point (now) where I have to insert the key, then vibrate it (actually using a very tight "sawing" in-and-out motion, while also turning it to the right) in order for the key to completely turn to start the engine. Works every time, and I do it without even thinking now, but how is even this not causing the SECURITY/lockout issue to resurface? Just turned 250,000 miles on the odometer last week.

 

Sí, la derivación de la resistencia funciona, pero solo para solucionar problemas con la función de bloqueo antirrobo del interruptor de encendido. No funcionará para ECM a BCM VIN desajuste u otras características de seguridad. Un llavero pesado o un giro rápido de la ignición para arrancar pueden causar que el contacto rebote dando al BCM una falsa alarma y un bloqueo de arranque, un interruptor de ignición de muchas millas tendrá mucho más juego mecánico y eso también contribuirá a las fallas de seguridad. Tengo un problema LS (detective) de 9C3 de 2003 y tuve que hacer el bypass, soldé una resistencia de 2,2 K al 1 % a los pines BCM y realicé el procedimiento de reaprendizaje sin problemas, pero no puedo hablar por el Equanox u otro modelos
Todos los datos de la clave de paso se almacenan en un área protegida del BCM ASIC y, una vez que se escriben, se bloquean; según tengo entendido, cuando la llave está en el interruptor de encendido, se envía una activación al ASIC y se emite un desafío, esto es lo que se usa para verifique la secuencia de cambio para la clave de paso y una respuesta válida establece el indicador de seguridad en cero, la secuencia básicamente proporciona un retorno de voltaje al BCM y eso se compara con el valor almacenado en el almanaque. La derivación de la resistencia emula una respuesta válida que proporciona una carga constante a través del pin a tierra y un voltaje que satisface el desafío. Creo que esto fue del orden de 4,35 voltios medidos en un Keithley DVM. Una vez que se realiza el desafío, el BCM vuelve a dormir y asume que la llave está en el encendido y espera el siguiente comando. El sistema de clave de paso es sólo reactivo,
Si el motor arranca, puede sacar el BCM por completo y conducir el automóvil; no se envió ninguna bandera de seguridad, por lo que se reiniciará sin el BCM en su lugar. Si bloqueó el arrancador, quitar el BCM no hace nada, ya que la bandera permanecerá hasta que el BCM la borre. Solo el velocímetro y el tacómetro funcionarán sin el BCM, ya que estos datos se derivan del ECM oculto en la caja del filtro de aire.
[/COTIZAR]
Amigo Hierbabuena, veo que Ud. tiene conocimientos del circuito de Passlock en Chevrolet, quería consultarte ya que aunque soy aficionado, me ha empezado a gustar este tipo de problemas en Impala, aunque he manejado algunas información dispersa, ya que no tengo sino fragmento de los diagramas electricos de este sistema, no manejo algunos conceptos básicos de electrónica, pero que me agradaría que me aclarase, si es que siendo evidente que el BCM es la Ruta a seguir por el circuito de SW de ignición, siendo correcto lo que dices sobre el desgaste de la llave SW, etc, etc... pero cuando se habla de " Bandera de seguridad", "clave", código R y otros términos para referirse a cierta programación para verificar " la secuencia de cambio para la clave de paso y una respuesta válida establece el indicador de seguridad en cero """ he aqui mi pregunta....dicho cambio de voltaje debido a la resistencia, NO ES SOLO la Referencia en cuanto a los umbrales de voltajes (< ó = a 5 v), que manejan, el ó los transistores de BCM para permitir que este modulo interconecte con PCM, ya que el circuito SW Iginicion no tiene interconexión directa con la PCM?? ni maneja circuitos electrónicos '??? interpreto que la BCM es solo la llave de paso a traves de sus transistores que manejan un voltaje predeterminado para activar su base y dejar pasar el voltaje que requiere la PCM para activar los pulsos de inyección ?? por favor Corríjame, y por favor y su opinión para librar mi ignorancia sobre el tema...

 

[/COTIZAR]
Se duplico el mensaje, disculpen !!

 

Solo inglés por favor. Otra publicación solo en español es eliminada. Comprendo?
Moderator

 

When you twist the yellow with the blackwhite and snip from ignition switch the yellow all the resistor will do is turn off security lamp ...no resistor lamp will stay on
Basically half a hot wire lol

 

Reason it went away was the security flag was reset in that 10 minute period and a valid response was received during the proceeding ignition switch cycle. Twisting the yellow with the blk/wht without the resistor is going to throw up a security flag and lockout as the BCM assumes a theft condition, the resistor emulates the passkey and tricks the BCM into thinking all is well, you will need a diagnostic code reader that is capable of reading body codes to see what the nature of the problem is. The crux of the issue points to a bad ignition switch and it's only going to get worse.