My truck anti theft deterrent system activated and would not allow car to start. After tinkering with the system 3 days and inspecting parts and wires I had it towed to dealer for diagnostics. The mechanic says I need the theft deterrent module replaced. I asked if the module is the one located around the ignition switch (i have been researching online all weekend and even took panels off to see the part beforehand). He says no it is the entire module that is under the dash. When my fiance asked if it is located behind the radio compartment he said yes.
Well I have researched a lot and only see that there is a theft control module which is by the ignition which ties into I believe the BCM which is located under the drivers dash panel where my parking break release and steering column is.
So what is located behind the radio? Is there some other module I am not seeing? I have a 2007 Chevy Tahoe LTZ 5.3L v8 flex. I feel like I am being lied to and just told any and everything. His responses are very vague and I am someone who wants to know exactly what my money goes to.
The part number he gave me for what he said has to be replaced is in fact the theft control module that attaches to the ignition cylinder. Can someone give me a diagram of the entire Passkey 3 system in a Chevy Tahoe? Is it tied directly to the BCM as I thought? And if that is replaced does it require relearning the key with a scan tool or can the key be relearned by the 10 minute increments relearn method repeating 3 times?
Under replacing Body Control Module (BCM) the Repair Manual states:
This procedure must be performed if the BCM, Passlock sensor or PCM is replaced. If BCM is not properly programmed, it will not control all the features properly.
- Ensure battery is fully charged and ignition switch is in the ON position.
- Connect a suitably programmed Tech II, or equivalent, scan tool to Data Link Connector (DLC).
- Access scan tool “Special Functions” menu and follow scan tool instructions to program BCM.
- If BCM fails to accept the program, inspect all BCM connections and ensure scan tool is equipped with latest software.
The PCM, BCM and Passlock sensor all communicate with each other but are separate modules. Theft deterrent programming(see below) must be performed anytime the BCM, PCM or Passlock sensor is replaced.
As for feeling like the dealer is giving you the run around. In most cases the dealership hires a sales rep for their Service Writer position. They are good at selling and usually not skilled mechanics. They rely on what the mechanics diagnosis is for each repair and build an estimate based on what parts are looked up by the mechanic. They then, to the best of their ability, try to explain this to the customer. In most cases they have no idea what is going on with your car or even know what color it is. They are more of a middleman between the customer and the mechanic. I wouldn’t hold there lack of knowledge against them.
Theft Deterrent Control Module Location
Right side of the steering column near the ignition key cylinder
Anti-Theft System Diagnostic Service, Test
A visual inspection must always be performed to confirm the presence of aftermarket components, potential collision damage, or areas of concern.
Most systems use a key with transponder, transponder receiver, transponder module and PCM, BCM or stand alone anti-theft module to control system.
The transponder equipped key is inserted into the ignition cylinder and the ignition switch is turned on. The transponder module wakes up and comunicates with the transponder receiver to determine if the appropriate key was used. If the key matches, the transponder module sends a signal to the PCM authorizing vehicle start. If the key does not match, the vehicle will not start and the security lamp will flash.
If vehicle has had a module replacement, a perimeter reset/module pairing, may be required before anti-theft system will operate correctly.
If vehicle is equipped with tow-away protection, antitheft can be sounded when vehicle is being transported.
Some models may have a anti-theft code recorded in radio, retrieve radio code prior to servicing.
Some models may be equipped with a manufacture assisted satellite anti-theft system. Review vehicle owners guide for more information.
1. Duplicate customer concern.
2. If vehicle is equipped with tow-away protection verify that it is disabled.
3. If vehicle is equipped with a interior motion sensor, verify there is nothing hanging from rear view mirror or coat hangers as this can trigger an anti-theft event.
4. If vehicle is equipped with a interior motion sensor and auxiliary heating system, one system should be deactivated as auxiliary heating system can trigger a anti-theft event.
5. Inspect for aftermarket components, such as a remote start or alarm.
6. Verify that hood, luggage compartment, and all doors are fully closed.
7. Verify battery is at full state of charge. Inspect battery condition and charge batteries, as required. An overcharge condition may also affect anti-theft system operation.
8. Ensure transponder key does not required battery replacement.
9. Inspect related fuses and fusible links.
10. Inspect condition of anti-theft lamp. If lamp is flashing perform following:
a. Remove any signaling devices or magnetic cards from key-chain and attempt to start.
b. Verify concern is present with each vehicle key. If concern related to one key, reprogram key and reevaluate system operation. If concern is still present with only one key, a replacement key is required.
c. Connect a suitably programmed scan tool to vehicle.
d. Perform network test and verify communications.
e. Inspect state of hood, luggage compartment, and all doors to verify showing closed on scan tool.
f. Verify programming of all keys. A system reset and reprogramming of all keys at one time may be required.
g. Retrieve any anti-theft related diagnostic trouble codes (DTCs) and follow appropriate DTC code diagnostics.
Theft Deterrent System Programming
The following procedure must be performed anytime the BCM, PCM or Passlock sensor is replaced.
1. Ensure battery is fully charged and there are no Diagnostic Trouble Codes (DTCs) present.
2. Turn ignition switch from the OFF position to the CRANK position attempting to start the vehicle. Vehicle should start and then stall.
3. After vehicle stalls, leave ignition in the ON position and observe security indicator on instrument cluster.
4. When security indicator turns off, turn ignition switch off and wait 10 seconds.
5. Repeat steps 2 through 4 two more times (3 times total).
6. BCM and PCM will learn the new code on the next start attempt.
