Need to verify that the rear differential is working properly on a 2021 GM Suburban? Whether you’ve just replaced the differential or you’re tracking down a strange drivetrain noise, this guide will show you exactly how to run a functional test using a Launch X431 scanner (like X431 V+ SmartLink HD or PRO3 LINK HD).
Why Perform This Test?
This function is designed to be run after repairing or replacing the rear differential or its related parts. It helps you confirm everything is operating as it should, so you can be sure the vehicle is performing at its best.
What You’ll Need:
- Vehicle: 2021 GM Suburban
- Tool: Any Launch X431 diagnostic tool
Let’s Get Started:
1. Fire Up Scanner:
On your X431 tablet’s home screen, tap “Local Diagnose” .
2. Connect to Suburban:
Go to GM and select the software version GM V50.10.
Choose “Automatically Search”. The tool will find your car.
When it asks, hit “Yes” to automatically read the VIN.
3. Get Car Ready:
Turn the ignition ON. Don’t start the engine.
Key-start: Just turn the key to the ‘ON’ position.
Push-button start: Press and hold the start button for about 5-10 seconds until the dash lights up.
Double-check that the vehicle info on the screen is correct.
4. Find Right Module:
Tap on “DCM” (that’s the Differential Control Module) from the list of systems.
5. Start Test:
Select “Special Functions” .
Look for and select “Rear Differential Functional Test Command”.
The screen will show a list of safety checks. Read them, then tap “OK”.
6. Check Conditions:
The scanner will check a few things to make sure it’s safe to proceed:
Are the rear wheels stopped? (Rear wheel speed = 0)
Is the ignition on?
Once everything shows as OK, you’re good to go.
7. Let It Run:
The screen will say “Processing…”. Just wait a moment.
Tap “Continue” when it pops up.
8. All Done!
You’ll see a success message: “Perform rear differential functional test successfully”.
That’s it. The test is complete, and you’ve verified the differential is functioning correctly.
Tech support:
E-Mail: sales@X431shop.de
Business WhatsApp: +86 17782330462
Tel: 0086-17782330462