Use the interactive guide above for a step-by-step walkthrough
After replacing a control module, your vehicle's security system needs to relearn communication with the new module. Here's what to expect:
When you replace the PCM/ECM:
β Exception: Not needed if PCM/ECM ordered with disabled VATS
β If ECM has IMMO: Requires key programmer, locksmith, or Auto 101 GM Tool
β Additional: May need Crankshaft Position Variation Learn (see below)
When you replace the BCM on 1999-2006 models:
When you replace BCM or Fuse Box on newer models:
GM uses two different security systems:
Critical: The 30-minute procedure does NOT work on IMMO vehicles! You must use the correct procedure for your vehicle.
Click the dropdown below to see if your vehicle is in the Global A list (IMMO system)
If you FIND your vehicle and year in the list: Use IMMO system (except Savana/Express β use VATS)
If you DON'T find your vehicle or year: Use VATS system
Chevrolet Express and GMC Savana (2014-2022) are listed in the Global A list above, BUT they use the VATS/V.T.D system, NOT IMMO!
Example: If you have a 2018 Savana, you'll find it in the list above, but you should still use VATS procedure!
Use this system if:
Use this system if:
For older GM vehicles, Non-Global A vehicles, and Express/Savana
Fast guide for ECM/BCM/VATS module replacement
Watch this if: You want a quick overview and faster method
β οΈ Requires: Scan tool to complete this procedure
Step-by-step visual guide for the full relearn process
Watch this if: You need detailed step-by-step instructions for the complete 30-minute procedure
Turn ON the ignition, with the engine OFF.
The vehicle learns the Passlock Sensor Data Code on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
If the security light doesn't turn off during the 30-minute procedure, your vehicle may need Vehicle Theft Deterrent (V.T.D) programming via GM SPS2 or our Auto 101 GM Tool.
The 30-minute relearn procedure may NOT work on all GM vehicles!
If the 30-minute procedure fails, programming may be required:
Both can be performed via:
For Global A vehicles (except Express/Savana)
How to Re-Sync IMMO After Replacing ECM
Depending on your module replacement, you may need these additional procedures:
Scan Tool Required: This procedure requires a scan tool. If you don't have one, click here to learn about our affordable scan tool options.
Crankshaft Position Variation Learn Tutorial
Scan Tool Required: This procedure requires a scan tool with Module Setup capability. Get our scan tool here.
β οΈ Important for Pre-2007 BCM: If you have code B1001 on a BCM manufactured before 2007, this procedure will NOT work. You must use GM SPS2 V.T.D programming or Auto 101 GM Tool instead.
SDM/Airbag Setup Tutorial
Alternative Method for GMLAN BCMs
β οΈ Brake Light Issue: You may notice the brake lights work in reverse β lights turn OFF when you press the brake pedal and turn ON when you release it. This calibration procedure will fix this issue and restore normal brake light operation.
Important: The 30-minute relearn procedure does not work on some GM vehicles. For these vehicles:
Both can also be programmed by a locksmith β or you can use our Auto 101 GM Tool to complete the relearn easily.
β οΈ Battery Requirement: Ensure battery voltage is at least 12V during the 30-minute procedure. A weak battery may cause the procedure to fail. Use a battery charger if needed to maintain proper voltage.
Solution: If the security light doesn't turn off during the 30-minute procedure, you may need V.T.D or IMMO programming via GM SPS2 or Auto 101 GM Tool instead.
Global A Vehicles (see list above) require IMMO relearn (key reprogramming). A key programmer, locksmith, or GM SPS2 will be needed to perform this relearn β or you can use our Auto 101 GM Tool to complete the relearn easily and efficiently.
Solution: Check the Global A vehicle list at the top of this page. If your vehicle and year are listed (except Express/Savana), you must use IMMO programming instead of the 30-minute procedure.
Simple Rule: Check the Global A vehicle list at the top. If your exact vehicle and year are listed, use IMMO. If not listed, use VATS. Exception: Express and Savana always use VATS even though they're in the list.
Read this before contacting support - find answers to common questions
Follow these 3 simple steps:
Quick Check Examples:
Don't worry about the technical term! Just look at the list in the dropdown above:
That's it! Ignore the technical terms and just check the list.
This is unusual. If it worked, great! But this typically means:
Action: If the vehicle starts and runs normally, you're good! Clear any remaining error codes with a scan tool.
This means the 30-minute procedure didn't work. You have 2 options:
Why didn't it work? Your vehicle may need V.T.D programming instead of the basic relearn.
YES! Very important:
NO! Best practice:
You need to start over completely:
Pro Tip: Always use a battery charger during this procedure to prevent failure!
The relearn failed. You must:
You have 4 options:
Note: The 30-minute procedure does NOT work for IMMO vehicles!
Usually 10-20 minutes with the right tool:
Yes, you typically need to program at least 2 keys to the new module. Some tools may require all keys to be programmed.
Best Practice: Have all your keys with you when programming.
These are security-related codes. Follow the normal procedure:
After completing the procedure, clear codes with a scan tool.
This happens after BCM replacement. Two options:
If BCM is 2007 or newer:
If BCM is older than 2007:
Yes, these codes mean you need Crankshaft Position Variation Learn:
Can't skip this! Vehicle may run rough or not start properly without this procedure.
This is normal after BCM replacement (2007+). Easy fix:
See Additional Procedures section for detailed steps.
If you have Brake Pedal Position (BPP) sensor, you need calibration:
At least 12V during the entire procedure:
Pro Tip: Connect a battery maintainer/charger during the 30-minute procedure.
Yes, but it's better to use a battery charger:
VATS! This is a critical exception:
Don't be confused by the list! Express/Savana are special cases.
Check the list:
Looking at the list:
Check these common issues:
For VATS procedure:
For IMMO procedure:
If all checks pass: Your vehicle may need professional programming (V.T.D or IMMO) via Auto 101 GM Tool, locksmith, or GM SPS2.
A blinking security light usually means:
Action:
You can attempt it multiple times, but:
Each failed attempt = 30 minutes wasted!
It depends:
DON'T need scan tool for:
DO need scan tool for:
For basic code reading = Yes
For special procedures = No
You need:
Visit: https://auto101.net/products/download?_pos=1&_psq=gm+tool&_ss=e&_v=1.0&variant=42362600980547
Why Auto 101 GM Tool?
If the car starts and runs:
If the car won't start:
You can do it yourself if:
When to call a professional:
| Your Situation | System to Use | Expected Time |
|---|---|---|
| Replaced PCM on 2015+ Silverado | IMMO | 15 min + tool |
| Replaced PCM on 2010-2013 Silverado | VATS | 30 min |
| Replaced BCM, security light on | VATS | 30 min |
| Replaced BCM, airbag light on (B1001) | SDM Setup | 10 min + scan tool |
| Code P0315 or P1336 | CKP Learn | 15 min + scan tool |
| Brake lights reversed | BPP Calibration | 10 min + scan tool |
| Express/Savana any year | VATS | 30 min |
| Security light won't turn off | Programming | 15 min + tool |
β±οΈ VATS = 30 minutes (no tools needed)
π§ IMMO = 15 minutes (requires programming tool)
π Battery voltage = 12V minimum (use charger!)
π± Express/Savana = Always VATS (never IMMO)
π― When in doubt = Check the Global A list again
Good luck! Follow the instructions carefully and you'll get your vehicle running! πβ¨
Contact us and ask any questions about your installation and we'll help you troubleshoot!
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