Can't Re-lean TPMS System and Key Fobs are Inoperative

Edward Owner/Technician San Antonio, Texas Posted   Latest   Edited  
Case Study
Safety
Chassis
2014 Chevrolet Tahoe PPV 5.3L (0 LMG) 6-spd (6L80)
C0775 - ISO/SAE Reserved

Key fobs are inoperative and the TPMS system is showing on dash as low reading on front left tire.

After successfully Initializing the TPMS relearn, I recycle the ignition key and the TPMS light came back on showing low pressure reading on the front left side

Used My Bartech Tech400Pro to check each sensor which Provides Test Before Touch diagnostics all TPMS sensor were with in spec.

Hook up a Snap on Modis Edge to check TPMS Date found that there was no communication with scan tool. 

Pulled up operational description found out that the Remote Control Door Receiver or RCDLR for short is a malfunction module does both keyless and TPMS.

Printed out a schematic to check power and grounds, Check DSM fuse 10 Amp at the I/p Fuse block Left end of dash no issue found at DSM fuse.

Check power and grounds at RCDLR Module which is located back rear comer upper garnish, everything was with in spec.

Guys, the serial data was the only thing left to check but I figure that if there was no communication with the scan tool, the RCDLR module is not communication that the issue was in the module so I decided to pull the RCDLR module and take a closer look and this is what I found was water intrusion on the circuit board as you can see. 

(Reinstall the new RCDLR Module)

Note: MusT reflash RCDLR Module with the latest software and calibrations, using Acdelco Tis2Web, the following will be necessary:

Relearn all keyless entry transmitters. 

Reconfigure the tire pressure placards and the tire type. This can be done with GSD2 or Scan Tool.

Relearn the tire pressure sensors. 

Guys if you have any input feel free to post, I’m always looking for new ideals or better route I should've took...

+6
Angel Technician
Boston, Massachusetts
Angel
 

Thanks Edward for sharing your case study with us. Good write up and case study. My only question is what caused the water intrusion. Nonetheless thanks for sharing.

0 Ð Bounty Awarded
Edward Owner/Technician
San Antonio, Texas
Edward
   

Hello Angel Thanks for the feed back , and yes unfortunately i did fail to mentioned the root cause this unit is a PPV unit they have several overhead aftermarket antennas which leak water in the back pillar area also there are after market radars installed in the rear upper driver roof area were metal seat screws are used and tons of silicone around the antennas and radars area unfortunately

+2 Ð Bounty Awarded
Angel Technician
Boston, Massachusetts
Angel
 

I deal with aftermarket upfitter work all the time working for the city. It is definitely a pain. Great find!

+1 Ð Bounty Awarded
Bill Owner/Technician
Jackson, Michigan
Bill
 

Good post only thing different I could suggest is to scope your data communication line instead of looking inside the module you can't count on finding visual evidence. If unsure of what data line should look like you could have recorded the known good after you installed the new module and verify proper function. This way you have for next time.😀

+1 Ð Bounty Awarded
Edward Owner/Technician
San Antonio, Texas
Edward
 

Hello, Bill Kenel Thanks for the feed back , and yes your 100% right, jump the gun to fast and not focusing on the facts, but hopefully i will come across another one by than i will have my ducks in a row. Thanks Again Bill

+2 Ð Bounty Awarded
Bentley Manager
San Diego, California
Bentley
 

Great write up. Had some success with wd-40 overnight soak, plastic brush cleaning followed with contact cleaner and clear coat. May bring module back to life.

0 Ð Bounty Awarded
Edward Owner/Technician
San Antonio, Texas
Edward
 

Hello, Bentley Greatly appreciate the feed back, and hopefully i will come across another one I will try the Bentley test. I would say Bentley never had a problem doing the ford wiggle test. Am always looking for new ideas .... Thanks again Bentley

0 Ð Bounty Awarded
Anthony Technical Support Specialist
Kirkwood, Pennsylvania
Anthony
 

Hi Edward: I'm surprised that you found the module. The one that I was involved with a few months back was a joy. One service information provider said it was in the "B" pillar. Another said that it was in the headliner. It matters if it is a PPV with a 1 piece rear door or a PPV with a 2 piece rear door. Oh, the module? It was in the rear door. The best part was that the tech from the cop shop

+1 Ð Bounty Awarded
Edward Owner/Technician
San Antonio, Texas
Edward
   

Hello Anthony Thanks for the input, I feel your pain not having all the facts can sure drive you up the wall. I got lucky service information was dead on but like Bill said in his early posting jump the gun little to fast and missed a crucial step in my diagnosis. Hopefully i run in to another one like this and won't have to play swaptronics but will be able to post more date. Thanks again

0 Ð Bounty Awarded