I don't know much but I know that's not right

Craig Technical Support Specialist Chicago, Illinois Posted   Latest   Edited  
Case Study
Driveability
2006 Jeep Commander Limited 5.7L (2) 5-spd (545RFE)
P2101 — Throttle Actuator "A" Control Motor Circuit Range/Performance
P2110 — Throttle Actuator "A" Control System - Forced Limited RPM

Vehicle has been setting codes on a very random basis, could not get vehicle to fault for us at any time. Customer states problem can occur multiple times in a day and then go for a week without an issue.

Vehicle has new throttle body and connector, driver circuits and TPS have been checked with no conclusive results. Online sources show the PCM as a likely candidate. Seeing that it was already remanufactured I decided to open the computer up and take a look around, the video shows what was found.

Never have I seen a capacitor floating above the circuit board held in only by conformal coating, I pulled it out like a loose tooth.

Cleaned up the area, resoldered and reattached the component, not sure if the vehicle is fixed, I will return to customer and see if this was the gremlin I was looking for. 

+11
Interesting
Helpful
Thanks
Agree
Michael Mobile Technician
Clinton, Utah
Michael Default
 

Hi Craig, Awesome Find! YOU DA MAN!

0
Default Ð Bounty Awarded
Craig Technical Support Specialist
Chicago, Illinois
Craig Default
 

Hello Michael, I understand you do this kind of work as well, do you have any recommendations as far as a conformal coating remover, that silicone snot is quite a pain to deal with. Thanks Craig

0
Default Ð Bounty Awarded
Michael Mobile Technician
Clinton, Utah
Michael Default
 

Craig, The snot needs to be placed back in the ECU for cooling. Remove as little of the snot as possible and do your best to shove it back in place. I don't have any easy methods for taking it or the shellac substance off boards. I can tell you some flux will break down the coating on the board so badly the pads under the IC will come loose. Kind of a trial and error thing.

0
Default Ð Bounty Awarded
Geoff Diagnostician
Lahaina, Hawaii
Geoff Default
 

Have you ever messed with the old Chrysler JTEC computers that are filled with gel? It's like the ballistic gelatin they use on Myth Busters...LOL Not sure how they reman those.

0
Default Ð Bounty Awarded
Craig Technical Support Specialist
Chicago, Illinois
Craig Default
 

Michael, good to know it's also a thermal agent. I basically created a crater, performed the repair and used some epoxy to hold the capacitor down. Then covered everything back with snot. Craig

0
Default Ð Bounty Awarded
Steve Instructor
Irvine, California
Steve Default
 

Great find. I really like that you went beyond your normal diagnostics to look into the PCM.

0
Default Ð Bounty Awarded
Tim Mechanic
Blytheville, Arkansas
Tim Default
 

That is a great find! Thanks for sharing!

0
Default Ð Bounty Awarded
Firas Owner/Technician
Sacramento, California
Firas Default
 

We have same issue before with same codes for 2016 Jeep Compass and we ending with change the ECU thank you for the info Craig

0
Default Ð Bounty Awarded
Hollis Technician
Boulder, Colorado
Hollis Default
 

That's how you cut to the chase. Curious, could you determine if the solder connections were cracked, failed due to heat or just insufficient from day one ?

0
Default Ð Bounty Awarded
Craig Technical Support Specialist
Chicago, Illinois
Craig Default
   

Hollis, I believe this was a failed repair on the PCM, I suspect the soldering or reflowing of this particular capacitor didn't get hot enough to melt the soldering paste. It looked like the component and leads were on top of the solder and not melted into it. Craig

0
Default Ð Bounty Awarded