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John, Master A.S.E Automotive technician
Category: Chevy
Satisfied Customers: 9176
Experience:  A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
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99 gmc: has to do with the passlock system

Customer Question

99 gmc jimmy starts then stalls think it has to do with the passlock system. new fuel pump everything is working
Submitted: 7 years ago.
Category: Chevy
Expert:  John replied 7 years ago.


Have you scanned the system for failure codes ?


To determine if a crank/no start or start/stall condition is being caused by a passlock theft deterrent concern, perform the following steps:

  1. Connect the Tech 2 to the vehicle, turn ignition to the on position
  2. Select the "POWERTRAIN" option
  3. Select "DATA DISPLAY"
  4. Select engine data and look for the "VTD FUEL DISABLE" parameter
  5. Crank the engine, If the "VTD FUEL DISABLE" indicates "ACTIVE", The passlock theft deterrent system is disabling the fuel and you need to follow theft deterrent diagnosis. When the engine is cranked, if the "VTD FUEL DISABLE" indicates "INACTIVE", The no start condition is NOT being caused by a theft deterrent concern and normal no start diagnostic should be followed..
Customer: replied 7 years ago.
the tech 2 would be what a gm scanner. I have the snap on ethos and i can get the motis will either of these work for this scan
Expert:  John replied 7 years ago.
Either snap-on scan should work ,as long as you can view the VTD fuel enable/disable parameter.I know the Modis will access this data.Make sure the scan tool software is up to date.
Customer: replied 7 years ago.
on the ethos it reads vtd disable off when then truck is in the on possision and when i crank it and it starts it reads vtd disable on.
Expert:  John replied 7 years ago.
Ok,check the body control module for theft deterrent codes.Most of the time it is the ignition lock cylinder or the BCM.
Customer: replied 7 years ago.
we tried the bcm still doing the same thing when we try to program the key the security light flashes once and then turns of right away and does not stay on for the ten min. we have another key cylinder so i guess thats the next step.
Expert:  John replied 7 years ago.
Look at fuel enable parameter on scan tool .if passlock system is stopping engine from running,it should say, "fuel disable".
Customer: replied 7 years ago.
we are going to try the key cylinder tommorrow or monday and see what happens
Expert:  John replied 7 years ago.
Ok,have a good evening.

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