2002 Firebird VTD / PASS-Key Diagnosis
2002 VTD/PASS-Key diagnosis built around what the SECURITY light actually does, tamper mode, fail-enable and stored-code routing.
Use SECURITY behavior to choose the branch
Reproduce the complaint with the same key and watch the SECURITY indicator while turning to START.
You can classify the result: normal indicator, flashing with inhibit, or SECURITY staying on while the car still starts.
Allow the tamper timer to finish
If the BCM reads the wrong key resistance, the 2002 system description allows a tamper mode of about 3 minutes that disables starter and fuel injection while SECURITY flashes. Stop cycling the key and let the timer expire.
After the timer, retry with the correct key under the same conditions.
Read BCM theft-deterrent codes before touching parts
Scan the BCM and record VTD codes. Keep PCM codes too. P1626/P1629 can be part of the fuel-enable/key-recognition path.
Stored codes and SECURITY behavior identify a VTD branch that can be followed with exact circuit information.
Understand fail-enable
The 2002 description allows fail-enable when the BCM previously recognized the correct resistance and the PASS-Key circuit later opens/shorts. In that state the SECURITY lamp can remain on while the vehicle continues to start.
Vehicle starts and runs even though SECURITY remains illuminated.
Know what the system is deciding before bypassing anything
The key resistor/contact circuit is read by the theft-deterrent system; the BCM decides whether the start is authorized and participates in the fuel-enable/start authorization path. A failure can therefore look different from a normal fuel or starter failure.
Symptom, SECURITY behavior and stored codes agree with the same branch.
Before you start
Confirm the page scope above, then work through the published checks in order. Use the linked exact-test procedure whenever this page sends you to one.
Modified car?Check first
This diagnostic path is based on the application shown on this page. If the car has non-stock wiring, calibration, engine-management, fuel-system, cooling-system, security, or other related changes, do not assume the stock path matches the car exactly. Verify the circuit and configuration actually present before using a stock result to condemn a component.
Working on a modified car? Check the modified-car note.
Progress is saved on this device.
Start here
Follow the tests in order. Use the result you actually get, not the failure you expect to find.
- Confirm this page matches the vehicle and symptom before testing.
- Gather the tools listed on the page before disconnecting anything.
- If a STOP warning appears, do not improvise past it.
- After a repair, repeat the failed test before moving on.
Diagnostic Workpad
Use this as a quick job-side record while you work through the tree. Record what the car actually does before moving to the next branch.
Your notes stay in this browser on this device. They are not sent to F-Body Parts Verdict.