2008 Saturn Aura (PCM & Dielectric Grease)

Brian Diagnostician Idaho Posted   Latest   Edited  
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Electrical
Network Communications
2008 Saturn Aura Green Line 2.4L (5) 4-spd (4T45-E)

Hello, 2008 Saturn Aura with several communication issues with the GMLAN or CAN Bus. I believe I found the problem as there was lots of dielectric grease in the BCM connector that I believe was causing the issues. I used an oscilloscope to find the issues within the waveform. What is your option on using dielectric grease on BCM or ECM electrical connections? I believe they can cause issues since dielectric grease is an insulator and can cause problems with low current such as a CAN Bus? Any advice is greatly appreciated. 

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Saifullah Diagnostician
Ontario
Saifullah
 

I personally have used dielectric grease many times with CAN wiring. Never had an issue.

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Benjamin Diagnostician
Connecticut
Benjamin
 

So I looked it up because I've heard differing opinions on the addition of dielectric grease. According to Nye Lubricants, the addition of the grease does not effect the conductivity of the circuit, as it does not prevent the pins from contacting.

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Robert Technician
New York
Robert
 

There was a recall on Aura and Malibu of that vintage to apply dielectric to bcm x2 connector due to terminal fretting causing poor connections most notably brake lights staying on

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Michael Owner
Alabama
Michael
 

static​.​nhtsa​.​gov/odi/tsbs/2017…​.​pdf

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Martin Instructor
British Columbia
Martin
 

Brian, as Robert alluded, coating with dielectric grease is a required step for terminal fretting issues that are not advanced. With clean terminals, coating with grease and installing the connector, seals from moisture entry. I've used Nyogel 760G that is available as ACDelco Electrical Connector Grease, for many years with great success. Dielectric grease does not inhibit connection…

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Stephen Technician
Tennessee
Stephen
 

I am glad that you posted the “Dielectric Grease vs Conductive Grease (w8ji​.​com) That article and the Nye Lubricant article linked inside of it should be required reading followed by a comprehension test for anyone in this profession. Well, at least read it, twice. Some of the acronyms and engineering language is hard to grasp but, the underlying information about the relationship…

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Martin Instructor
British Columbia
Martin
 

There is definitely some worthy reading on the topic. Years ago over on the old site, the topic raised plenty of debate and it was clear that there was a lack of understanding of the engineered functions of electrical connectors, leading to what I coin as “mythunderstanding” and “mythbelief”. Just like most everything else, conductor terminations are subject to the effects of vibration, heat…

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Glenn Owner/Technician
Texas
Glenn
 

Hi Martin, I am sure you remember the light-yellow (baby caca) terminal goop many manufacturers used years ago especially in 1156, 1157 bulb sockets. It was common to see that stuff flooded into the sockets like it was applied with a caulking gun during factory assembly. Terminal fretting and scrubbing are a real issue that has not improved over the years. Once upon a time these connections…

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Tony Owner/Technician
Missouri
Tony
 

I was going to say what Robert said. The Micro 64 pins are frail and are not durable or well suited for higher current circuits. In the case of the BCM brake light situation I believe they even fail when low current “switch” data is being passed through them, let alone “high” current brake light voltage. Do a pin drag on any suspected BCM harness terminal to see if one of them is weak. The…

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Glenn Owner/Technician
Texas
Glenn
 

Hello Brian, Die electric compound is not a cure all, end all for electrical connectors, but it has been proven for many years to prevent moisture intrusion and reduce or eliminate terminal fretting. Just like anything else, too much of a good thing can be bad. Use it sparingly is my advice.

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Jason Owner/Technician
Virginia
Jason
 

The problem is most people glob it all over everything which can end up blocking connections, especially when terminals are a little worn/loose. If applied lightly it works well.

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Raymond Mobile Technician
Michigan
Raymond
 

Hi Brian, I have diagnosed and run into this BCM connectors and dielectric grease all the time, man it seems like the dealership has that stuff in a 55 gallon drum with a ratcheting pull down down gun (lol) anyways yes I see using too much dielectric grease is the problem, there is claims that too much grease can push pin apart from each other , so using sparingly is the way to go , what I do is…

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Steven Mechanic
Washington
Steven
 

I've also seen issues when someone applies too much dielectric grease. I would only use it where it is called for, and only apply a very light coating. Using too much has the potential to cause problems.

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Laird Owner/Technician
Nova Scotia
Laird
 

The problem I have seen with those is they stuffed the connector with the die electric grease and it must cause the connector to not seat correctly. I usually use an air gun and blow the excess into a rag and the problem is fixed. You are supposed to use it sparingly

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Bill Diagnostician
Pennsylvania
Bill
 

For the past 5 years or so I have been using brush in can silicone paste. It's much easier to apply and I have never had a negative issue with it. As others have said, moderation is best. I use it on all the sensor connectors and computer connectors I take apart daily. It is very useful in keeping other contaminates out. There have been many times when it has solved a loose connection issue and…

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Brian Diagnostician
Idaho
Brian Resolution
 

Thanks everyone for all of the information. I really appreciate it! Brian

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