2003 Chevrolet Monte Carlo Logo
Posted on Jul 19, 2011
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Hello. I have a 2004 Monte Carlo SS. Just recently, I have experienced my car not starting. I have had ONSTAR do a Diagnostic test from my car, while I am in it, and it comes back fine. What happens is, I go out start car, drive somewhere, no problem. After that stop, I have a 50/50 chance it is going to start. When it doesn't start, my security light flashes on my contol information box on dash. I wait for about 15-20 minutes, Lightly tap the break down and switch it into N and it starts. Sometimes the light stays on...other times it goes off when I am driving. Sometimes my car starts, but my Security light stays on steady the entire time I drive it, till I shut it off. It usually starts the time after that, and the light is off. It is crazy, because I have these problems at the worst possible times. It is annoying. First, does it hurt the car to drive it like this? Second, whats wrong? The lights light up on dash, the radio works, air/heat works, lights work, etc. The only thing is it doesn't start. Please help me with this ASAP.

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  • Master 506 Answers
  • Posted on Jul 19, 2011
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Read the following paragraph from GM, this will give you some insight on the passlock system on your vehicle.

The electrical switching portion of the ignition lock cylinder assembly is separate from the key and lock cylinder. The electrical switch portion and the key and lock cylinder synchronize and work in conjunction through the action of the mechanical assembly between the two components.

PASSLOCK(TM) SENSOR
The Passlock(TM) sensor contains 2 hall effect sensors. The tamper hall effect sensor is on the top. The security hall effect sensor is under the tamper hall effect sensor. Both of the hall effect sensors monitor the magnet of the lock cylinder through an opening. The tamper hall effect sensor is physically placed on top of the security hall effect sensor. This arrangement enables the tamper hall effect sensor to engage first if an intruder attempts to bypass the Passlock(TM) sensor by placing a large magnet around that area of the steering column. There is a tamper resistor inside the Passlock(TM) sensor in order to help prevent tamper to the system. Passlock(TM) equipped vehicles have a selection of 10 different security resistors ranging from 0.5K ohms up to 13.6K ohms . Installing one of the security resistors inside the Passlock(TM) sensor will generate a unique Passlock(TM) code. All 10 combinations of the Passlock(TM) sensor have the same part number.

BODY CONTROL MODULE
The body control module (BCM) contains the theft deterrent system logic. The BCM reads the Passlock(TM) data from the Passlock(TM) sensor. If the Passlock(TM) data is correct, the BCM will send a class 2 message to the PCM to enable the fuel injectors and crank relay.

During the tamper mode the vehicle may start. The vehicle will then stall. If the BCM receives the wrong Passlock(TM) data, the VTD system will immediately go into the tamper mode. The tamper mode will lock-out the vehicle fuel injectors and crank relay for 10 minutes . The SECURITY indicator will flash while the VTD is in the tamper mode.

If the Passlock(TM) sensor sends a correct password to the BCM when the ignition is in the ON position, the BCM will send a fuel enable and crank relay enable signal to the PCM.

SECURITY INDICATOR
The SECURITY indicator appears on the message center inside the instrument cluster. If the SECURITY indicator flashes or if the SECURITY indicator lights continuously during vehicle operation, refer to the system diagnosis.

POWERTRAIN CONTROL MODULE
The PCM communicates with the BCM over the Class 2 serial data line. When the BCM determines an incorrect password, it sends a Class 2 serial data password to the PCM in order to disable the crank relay and fuel injection system. If the BCM receives the expected voltage from the Passlock(TM) sensor, the BCM sends a class 2 serial data password to the PCM in order to enable the crank relay and fuel injection system. The PCM then allows the vehicle to start normally.

FUEL LOCKOUT CYCLE
The Passlock(TM) system has a lockout cycle of approximately 10 minutes . Once the vehicle is in the lockout cycle, the vehicle remains in the lockout cycle for 10 minutes , even if the ignition switch is turned from the ON position to the OFF position.

The Passlock(TM) system uses the lockout cycle in order to synchronize all of the Passlock(TM) components when any Passlock(TM) related part is replaced. The Passlock(TM) system requires 3 consecutive lockout cycles in order to complete the 30 minute learn procedure for a changed component.

CHANGING THE PASSLOCK(TM) COMPONENTS
The design of the Passlock(TM) system is to prevent theft even if the various theft deterrent parts change. The parts that can no longer be changed without the possibility of going into a tamper mode are:

* The Passlock(TM) sensor
* The BCM
* The PCM

If you replace any of these parts the vehicle may not start for 10 minutes . This is the long tamper mode. If this occurs, the system must go through a long tamper mode cycle. During this time the SECURITY indicator will be flashing for the full 10 minutes and DTC B3031 will be set. The BCM and the PCM require the full 10 minutes in order to complete a learn cycle. The ignition switch must remain in the ON position until the SECURITY indicator stops flashing. You will need to repeat the cycle if the ignition switch does not remain in the ON position. When replacing any of the above parts, perform the Programming Theft Deterrent System Components procedure.

The design of the Passlock(TM) system is to prevent the vehicle operation if the proper ignition key is not used in order to start the vehicle. The mechanical key, in normal operation, will turn the ignition lock cylinder. The Passlock(TM) sensor monitoring the position of the lock cylinder will relay the Passlock(TM) data to the body control module (BCM). The BCM will determine the validity of the Passlock(TM) data. The BCM will send a password to the powertrain control module (PCM). When the PCM receives the correct password the PCM allows the crank relay and fuel injectors to operate normally. The Passlock(TM) system requires the PCM and the BCM to communicate the various functions in order to operate. These functions transmit over the class 2 serial data line. For an explanation of the class 2 serial data description and operation refer to Data Link Communications Description and Operation in Data Link Communications.

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  • Chevrolet Master 2,229 Answers
  • Posted on Jul 21, 2011
Joe Taylor
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Yes, you obviously have a failing Passlock system. To fix this problem your self, go to this link.

http://vatspasslockpasskeysecurityhelp.yolasite.com/

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emissionwiz

Marvin

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SOURCE: 2004 monte carlo sunroof won't close

THERE IS NO MAN OVERIDE, REMOVE THE DRIVE MOTROR AND THE SUNROOF WILL CLOSE.

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ginko

Ginko

  • 19396 Answers
  • Posted on Feb 27, 2009

SOURCE: 2002 monte carlo ss

The fuel filter is located in the pressure line that runs from the fuel tank to the engine, near to the fuel tank.
Keep the engine off for few hours before replacing the filter, to get rid of some pressure in the lines.

Anonymous

  • 14 Answers
  • Posted on Jun 23, 2009

SOURCE: 2003 Monte Carlo SS Hesitates and Dies after running for awhile

The ck engine light should not be ignored, what sensor was shown to be bad ? Have it scanned again and replace the sensor that is bad if it still runs rough you might want to consider a tune up. Plugs, wires, fuel and air filter's and clean the throttle body with some gumout. It could also be the IAC motor Idle Air Control. Good Luck

Anonymous

  • 4669 Answers
  • Posted on Jul 07, 2009

SOURCE: 2002 monte carlo front end vibration

Does the left front go click, click, click on tight slow turns.

Anonymous

  • 273 Answers
  • Posted on May 17, 2011

SOURCE: My 2002 monte carlo ss sunroof won't go all tha

Sounds like it is going off track whenever it gets to the popping sound point. Or its catching against something, Check to see if anything could be in the tracks of the sunroof. Hope this helps, James Booth. Let me know what happens

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