Fault Stacking & Cascade Failures - Strategy and Damage Control

Benjamin Diagnostician Connecticut Posted   Latest   Edited  
Discussion
Electrical
Management
Multiple Faults
Water Damage
Short Circuit

So there's something that water and other liquids do both in the short term and the long term. Of course, in the short term, water causes short circuits, diverting electricity and resulting in random glitches and gremlins, which can be difficult to find and exterminate. The fix is usually quite dramatic: blow out the water with an air gun and everything starts working immediately.

On the other hand, long term water causes corrosion, even more difficult to trace, especially in black-box components, like radios and ECUs. I've noticed I often will find multiple faults in the same system and I'm trying to wrap my head around how to diagnose these without resorting to swap-o-matic diagnostics. Then, how do we handle additional faults after an initial repair?

Tuesday a 14 Lexus GX comes in with an inoperative navigation / multi-display. I check powers and grounds, NPF, but note the auxiliary input jack is flickering. On closer inspection, I can see that it's corroded, so I figure this must be the problem. I install a new jack, and everything lights up; no flickering, full audio/visual functions. I take it for a test drive to reset the navigation system and listen to the radio and media system, just to make sure all functions are 100%. It's the end of the day, so I put the car to wash and punch out.

I'm not 15 minutes on my way home and my writer calls me and says the screen went black when the customer had a phone call. He figures probably a phone issue (we have compatibility issues when the contact list is overloaded or has emojis in the wrong fields) so he deletes all the phones from the unit and restarts the vehicle. Everything working fine again.

Wednesday morning, the car comes back with the display out again (rear view camera works fine, but that's a different input). The new input jack is flickering again, too, so it seems that was a symptom, not a fault. Digging deeper, I pull the head unit and notice some corrosion on the case, but nothing on the pins (but who knows what's inside the black box?) I pull the display and notice similar corrosion on the case, also in a few of the pins on one of the connectors (related to rear view camera, not the audio/visual system). I clean what corrosion I can see and reassemble, but there is no change. I disconnect the auxiliary input jack from the rear of the head unit, which stops the flickering jack, but doesn't restore system functionality.

After a few minutes looking at wiring diagrams, I notice the display with only the message “A program could not be read, please consult your dealer.” This basically confirms the head unit is toast. After the customer already spent however much for me to diagnose and replace the jack, now I have to tell him he needs a $5,000 head unit, for which he's now contacting his insurance company.

So a couple of questions come up:

  1. Do you think there was something I could have done differently, or did I just get trolled by a bottle of Fruit Punch, the gift that keeps on giving?
  2. How do I work with the customer on this. In their eyes, I failed. It seems like a teaching moment, but I'm still learning how to do this with customers.
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David Business Development Manager
Ohio
David
 

Hello Benjamin, Did the customer tell you that a drink was spilled over the head unit (I'm guessing no)? My take is this vehicle ended up having multiple failures. You located a failure that was successfully repaired and resolved the issue at the time. Unbeknownst to you, a secondary failure reared its head. In my opinion, I don't see what you could have done differently (unless the customer…

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Benjamin Diagnostician
Connecticut
Benjamin
 

Who ever admits that? I've had 4 cars in the last week alone with water problems that no one knows anything about. The only reason I know it's fruit punch is because the car smells like a daycare and I found the bottle, hahaha! Catching that failing component before it's become a hard failure bothers me, especially when I have to try to explain it to the customer.

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Jamie Owner/Technician
Ontario
Jamie
 

That darn rule that says there can always be more that one problem. You did everything you could, had the jack fixed one issue and another still existed…you would have kept going, unfortunately not the case. We all get kicked in the knee now and then, yesterday was just your turn.

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Benjamin Diagnostician
Connecticut
Benjamin
 

Yeah, I may have been a little close-minded on the initial diagnosis. Having seen the corrosion in the jack, I should have thought to look up and down from there and see if there was any additional damage.

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Michael Technician
Indiana
Michael
 

Benjamin, If you had called your customer after replacing the jack, Said “We are XXX dollars into this and it seems to be functioning at this point. In order for me to feel confident in this repair, I need to spend more of your money, to look for a problem that I'm not sure you have” You work till it looks like your anomalies are gone. No more anomalies, equals no more charge to the customer…

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Rolando Diagnostician
Texas
Rolando
   

Seems like you did everything right. The only thing was how much corrosion you could VISUALLY see? What I do to try (keyword:try) to prevent stuff like this, is I look at how much moisture, staining, corrosion and possibly mold or mildew is present, then determine what components are in the area. From there, I would interrogate the customer and give them a rough estimate of how far down I have…

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Benjamin Diagnostician
Connecticut
Benjamin
 

Agreed, the additional communication and diagnostic time would probably have made the secondary findings easier to palate.

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Dan Owner/Technician
Texas
Dan
   

… Ben … This is where some pictures taken and shown to the customer (of the corrosion) really shine thru… they will show your concerns and reinforce the FACT that corrosion IS present and give you some ammo in case other problems arise… use your phone to record these things… my new Autel MS906BT has a very nice onboard camera that I plan on using (when I get the hang of it (just got it…

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Benjamin Diagnostician
Connecticut
Benjamin
 

Having the camera on-hand has been such an excellent diagnostic and selling tool. I always have my phone, scratches, dents, puddles, corrosion, warning lights and messages, underbody stuff, anything to explain my case for whatever. Definitely good to keep in mind.

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Glenn Owner/Technician
Texas
Glenn
 

Hi Dan and Ben, Dan, congrats on the MS906BT. I've had mine going on 3 years and really like it. The camera function is great for file attachments and Show & Tell with a customer. Of course, my expense for printer ink went up a little when a customer wants a picture or two. I usually provide a printout with my repair orders. I do not recommend simply emailing a customer a digital file with…

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Benjamin Diagnostician
Connecticut
Benjamin
 

This kind of stuff isn't the usual customer conversation, for certain.

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Michael Owner/Technician
Georgia
Michael
 

Hi Benjamin, You probably did everything right on your end but I'm sure the customer might have a different perspective. The only thing I might have done differently is setting up the customer that water/liquid damage can and usually does cause other problems. I would tell the customer this where we need to start but there is a chance I could be calling you back needing to diagnose/fix other…

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Benjamin Diagnostician
Connecticut
Benjamin
 

The customer perspective is what I'm chasing right now. Just for next time to set their expectations more realistically. Thinking back on it, I should have dug deeper when I saw the corrosion in the auxiliary jack. Great tip on the used units. I try to stay away from those, but sometimes it's unavoidable.

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Michael Owner/Technician
Georgia
Michael
 

That's going to be the tough part. I usually take ownership of the situation and tell the customer I know better than to guarantee a total fix in cases like this because it rarely is just one thing with water/liquid intrusion problems. I jumped the gun when the auxiliary port brought everything back to life. One thing we fight regularly in our industry especially with electronics is did the…

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Rod Diagnostician
California
Rod
 

You did every thing right. Do not allow these situations to beat up your self esteem or your self confidence. There is no way to get accurate vehicle history , The only failure was the service writer not informing the customer ahead of time that these type of problems can cost many thousand's of dollars to repair and get a commitment from the customer. Do not allow any one to use you a scape…

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Benjamin Diagnostician
Connecticut
Benjamin
 

Thanks for your words of encouragement. I have to admit I don't have too high of an opinion of myself. I try to let other people do that. I get complacent and then I turn into a @$$. Informing the customer properly is definitely a good idea. That way, they know better what to expect from the situation. It could be a 5¢ fuse or a $5,000 head unit. No way to tell until you're armpit-deep in it!

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Rod Diagnostician
California
Rod
 

Just a suggestion, start documenting all your successes, writing, videos, pics. Any time self-doubt creeps in review your successes. In private say them out loud in front of a mirror, the sound of your voice will be the most familiar to your brain. This is a technic used to start overriding the negative self-talk script triggered by people who lack empathy when they interact with you.

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Benjamin Diagnostician
Connecticut
Benjamin
 

thanks!

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Eric Manager
Arizona
Eric
 

I have to concur with everyone else. Good job and don't beat your self up. As lessons learned from similar problems. Now always tell customers with corrosion issues. Fix what is obvious and then see if any other damage from circuit problems.

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Steve Technician
Pennsylvania
Steve
 

Whenever I have something like corrosion on an interior part, where you wouldn't normally expect to see it, I will request that the Service Advisor re-interview the customer to get a more detailed description of what, when and where. In the dealership environment I don't feel it's appropriate for me to interact with the customer, unless requested. Too many times I have been put in a similar…

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Benjamin Diagnostician
Connecticut
Benjamin
 

That middle “C” sometimes is ambiguous. In other situations I've seen where it was a previous owner who did the deed, so even then might be impossible to get the whole story up front.

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Rex Technical Support Specialist
Ohio
Rex
 

Speaking philosophically the public seems to hold us to a higher standard than doctors are held to. In terms of getting everything right the first time. If diagnosis A doesn't fix you it is on to B and C and D etc. Unlike us the medical industry is billing and collecting every step of the way. Insurance of course factors into this as in most cases the customer is not directly paying the entire…

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Benjamin Diagnostician
Connecticut
Benjamin
 

I'll admit my bedside manner is a little lacking, (My wife of 17 years is still waiting for her storybook proposal.) so much of this has to do with getting the right message across to the customer. As shop foreman and diagnostic technician, I'm usually jumping between front-end and back-end operations.

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Dan Owner/Technician
Texas
Dan
 

… “I'm usually jumping between front-end and back-end operations.” …. I find myself doing that very same thing with my wife of 35 years {8^)~ … LoL … Dan H. … Hobbs

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Grant Technician
Illinois
Grant
 

You recommended the Aux port based on the corrosion without further testing while the display was inop. While I would have recommended the Aux port as well, I would have focused on the original complaint and not sold the Aux port yet. Why would an Aux port shut down the display? Unplugging it to see if the display symptom changes seems like a good next step. What I'd do next depends on the…

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Benjamin Diagnostician
Connecticut
Benjamin
 

Yes, I can see your point. The display returned when I unplugged the jack, so I concluded the jack was the issue, but the failure was so random. If only I'd waited a few more minutes, heh!

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Stephen Technician
Tennessee
Stephen
 

This type scenario cause my flight or fight responses to kick in and I can’t fly. Do techs in fleet and government or industrial repair have their pay deducted when the machine that they worked on yesterday has a problem today? The tech doesn’t get a share of the company profits, why do they get a share of the losses? What if, a car comes in with a misfire, pull the plugs, one looks funky…

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Benjamin Diagnostician
Connecticut
Benjamin
 

Yet another reason the FR system is BS, but that's a discussion for another forum.

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Stephen Technician
Oregon
Stephen
 

Lotsa wisdom and support from the community here thankfully as we all need it from time to time. What exactly do you think you could have done to prevent a damage that was already done? Would you have disassemble the unit and washed and dried it to prevent the imminent failure? Would that meet operational conduct at your place of business? I would approach the customer with these questions and…

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Benjamin Diagnostician
Connecticut
Benjamin
   

Yes, I certainly appreciate everyone's wisdom expressed here. Still have a ton to learn, but one day at a time I learn something new. Regarding how much service we actually offer, “reading the crystal ball” certainly isn't one of them. Working with the writers and service manager to help set the proper expectations.

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Rex Technical Support Specialist
Ohio
Rex
 

“help set the proper expectation.” That is the MOST important part. Same as the old old saying. Underpromise, overdeliver. Simple to say hard to execute. Ties into estimates. To often we think the customer is going to “shop” us. In reality, most good regular customers just need a number so they can plan. Estimate high! To often we shoot ourselves in the foot, ESPECIALLY on diag. Saw a great post…

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