2021 Stop Sale on certain diesels incoming (intake air heater relay). - Recall Y76 REFRESHED OCT 2021

[Brewbud]

We wouldn’t.

But don’t underestimate the manufacturing process to skip a step and then have some program manager just yell “ship it!” because otherwise his Excel status spreadsheet will get all messed up.

Very surprising to see this from the Germans, though. Usually they are pretty tight.

It is the high-performance air-cooled model. 0 to burn up in 6 seconds.

Can the battery terminal be disconnected on the 2019s and 2020s with the older style solenoid also be disconnected without throwing a code?

 

[steverud0121]

Thanks Jimmy07! That makes more sense.

So, yes, I can confirm, tested my Grid Heater (Cold Start Aid) in my driveway, with an infrared thermo... and ... no defect. Whew.

What temp difference are we looking for when engaged vs not engaged threshold ?

 

[rfullen280]

What temp difference are we looking for when engaged vs not engaged threshold ?

Interestingly enough, when you read the TSB procedure, it only specifies not to exceed 80C, I would assume start temp is irrelevant... or at least should be close to the temp of any other components in the area.

 

[steverud0121]

Interestingly enough, when you read the TSB procedure, it only specifies not to exceed 80C, I would assume start temp is irrelevant... or at least should be close to the temp of any other components in the area.

ha got it, thats pretty close to plastic melting point

 

[wolfpack]

Here’s mine. 169AA with just tape on the back of it.

 

[rfullen280]

Here’s mine. 169AA with just tape on the back of it.

Interesting. So, that's the kind that they'd RTV over instead. I'm guessing for those, moisture and muck accumulate behind the tape.

 

[Will_T]

I am not sure I was able to follow exactly all the possible contingencies in that PDF of the recall and testing document but what I wonder is this:

If the testing completes without exceeding the temperature parameter, etc. etc., and the vehicle is returned to the customer, doesn't that just indicate that specific relay was working OK at the moment of testing? What is to say that 100 hours down the road it won't overheat and catch fire?

 

[Combra6589]

So is there any insider that can give a better date other than February? Blows my mind that they have no issue letting my truck sit till then . Engineering needs to get their act together and send dealers these fixes.

 

[Will_T]

Here’s mine. 169AA with just tape on the back of it.

Thanks! I think you saved the rest of us from having to remove the whole relay to check. If you have a 169AA like I do, you have the tape, not the insulating goo.

 

[rfullen280]

I am not sure I was able to follow exactly all the possible contingencies in that PDF of the recall and testing document but what I wonder is this:

If the testing completes without exceeding the temperature parameter, etc. etc., and the vehicle is returned to the customer, doesn't that just indicate that specific relay was working OK at the moment of testing? What is to say that 100 hours down the road it won't overheat and catch fire?

That's a really good question, but we call it a relay, but I suspect it's a Solid State Relay, and looking at their pictures and where to measure temp, I'm guessing it's a defect in the output driver silicon that they're checking for. (hence the 600 hours..it ain't burnt yet, so it won't burn later )

That said, I doubt these SSR's have serial numbers, maybe lot numbers at best.

What is the Solid State Relay (SSR)?

This is an introduction to solid state relays, and you will learn what is a solid state relay? what are the types of solid state relays? how do solid state relays work? how to select the solid state relay? how to use solid state relays?...

www.huimultd.com

 

[Will_T]

So is there any insider that can give a better date other than February? Blows my mind that they have no issue letting my truck sit till then . Engineering needs to get their act together and send dealers these fixes.

That is frustrating for sure. Especially as it seems that possibly you could be good to go depending on what the inspection and testing finds. And I think the PDF says one of the fixes is to spread that insulating compound around and over the back of the relay. Is that compound really unavailable until February??

 

[rfullen280]

So is there any insider that can give a better date other than February? Blows my mind that they have no issue letting my truck sit till then . Engineering needs to get their act together and send dealers these fixes.

Problem is, Engineering comes up with a design, Manufacturing somewhere has to make it. And then, 6Sigma and Quality Control have to be in the driver's seat. Odds are, it's a material defect in the silicon on the output driver circuit...based on what I'm seeing in their pictures.

Plus, it being a Solid-State Relay... those materials are in short supply globally.

 

[Brutal_HO]

Kapton tape is good up to around 250C but if the bond is compromised, it's going to be a problem.

I'm surprised they didn't full pot those relays.

 

[Will_T]

I'm guessing it's a defect in the output driver silicon that they're checking for. (hence the 600 hours..it ain't burnt yet, so it won't burn later )

And those of us that are disconnecting the relay may be messing up that testing assumption. eg: If I disconnect it at 300 hours and by the time I get the truck in for the recall it has 700 hours on it, that test is not valid as the relay still only has 300 hours. I am disconnecting mine today but I will note the hours on the truck so I can "relay" that information to the dealer at the time of the test.

 

[rfullen280]

Kapton tape is good up to around 250C but if the bond is compromised, it's going to be a problem.

I'm surprised they didn't full pot those relays.

Same. Something tells me that full potting was in the original design, but some young accountant figured tape cost a couple pennies less. Or, some QC person thought "we can better inspect those terminal junctions if they're not potted". Potting should have been the last step.

Either way, it's a cluster fracas.... I would not be surprised if the original AA design has poor Kapton bonding, moisture got behind, and caused arc/flash/fire.... that's why the first recall on the AA's was to just slather with RTV.

 

[rfullen280]

And those of us that are disconnecting the relay may be messing up that testing assumption. eg: If I disconnect it at 300 hours and by the time I get the truck in for the recall it has 700 hours on it, that test is not valid as the relay still only has 300 hours. I am disconnecting mine today but I will note the hours on the truck so I can "relay" that information to the dealer at the time of the test.

That's also one possibility in a series of possibilities.

I checked with the ol' infrared thermogun, that met the specs of their TSB... and that may cause failure tomorrow... not much I can do about it, is there? But I've been in my truck numerous times since I got it in July 2021, and "waited" for the preheat...

 

[cycling4life]

And those of us that are disconnecting the relay may be messing up that testing assumption. eg: If I disconnect it at 300 hours and by the time I get the truck in for the recall it has 700 hours on it, that test is not valid as the relay still only has 300 hours. I am disconnecting mine today but I will note the hours on the truck so I can "relay" that information to the dealer at the time of the test.

Could one just do the double press start to bypass the heaters "wait to start" rather than disconnecting the relay from the batt?

 

[Will_T]

That's also one possibility in a series of possibilities.

I checked with the ol' infrared thermogun, that met the specs of their TSB... and that may cause failure tomorrow... not much I can do about it, is there? But I've been in my truck numerous times since I got it in July 2021, and "waited" for the preheat...

Yes, my thought was just that by disconnecting the relay we are invalidating the engine hours parameter in the recall instructions as it relates to hours on the relay.

Also it was said in an earlier post that the waiting for the preheat portion of the relay/grid heater usage is a small percentage of the time it is working. Supposedly it cycles on and off as you are driving as long as ambient air temp is below a certain level.

 

[Will_T]

Could one just do the double press start to bypass the heaters "wait to start" rather than disconnecting the relay from the batt?

My understanding is no since some of these fires may be occurring when the truck is just sitting overnight. Also as noted above the grid heater may cycle on and off after you start driving.

 

[rfullen280]

Could one just do the double press start to bypass the heaters "wait to start" rather than disconnecting the relay from the batt?

A silicon failure in the driver output side can only be prevented by removing the driver input power source.

And yes the truck cycles of the grid heater when its first warming up on a cold day just to aid in cold weather combustion until the cylinders are up to temp.