Old School vs. New School Diagnostic Approaches

Michael Mobile Technician Clinton, Utah Posted   Latest   Edited  

Changing ones mindset is really difficult especially when you feel that you are wasting time going through the actions. I was called to a repo lot today to diagnose an inoperative turn signal on a 2003 Toyota Sequoia. The first tool I hooked up was a scan tool to look at live data or command the signal on. No such option. I grabbed another tool to make sure. Same result. The second task was to look at the schematic to see how the signals are wired. The signal flasher / relay was wired into both the hazard and turn signals. I checked for power at the relay. There were two leads powered. This matched the schematic. I checked the grounds, all good. I switched the hazard button on and there was continuity. Same for left turn and right turn. So with that I was able to determine that the turn swich, hazard switch, powers and grounds were all good. The conclusion is that the electronic relay was toast. The relay was not to be found at any local parts store. I ordered from the dealer. It will be here next week. The part retails at $70. Customer will have to wait.

Back in the day, the flasher relay was the first thing. No flashers, change the relay. If they go too fast or too slow, put in a motorized one. They look cooler anyway. You can see all the electronics inside. The flashers were $3.99 or $12.99 for the motorized one. So when I was young, it was worth the risk to just throw a part at it. You could absorb the cost or shelve the part if you were wrong. It could be shorts, bulbs or opens. No matter, if changing the relay does not work, go to plan b. In this case plan b would be to do the testing above. The customer would have an extra $70 on his bill in the modern example if the problem were elsewhere.

In classes we are taught best practices in electrical testing. Somehow we develop bad habits to shortcut. Can we afford to make mistakes like we could in the past?

So I spent about 45 minutes in testing. Did I waste the customer's time?

-Mike

diag​.​net/file/f11hmkhej…

diag​.​net/file/f28whcs0v…

+4
Bob Owner/Technician
East Longmeadow, Massachusetts
Bob Default
 

It always seems obvious once the problem is found. You could have gone two different ways to diagnose this and you would have a 50/50 chance of picking the right path. In this case, the testing first makes more sense since the cost of throwing a part is fairly high and not worth the chance.

+2 Default Ð Bounty Awarded
Sam Mobile Technician
Flint, Michigan
Sam Default
 

I was taught when I started by one of the best electrical guys I have ever worked with that you never waste money testing. You only waste money guessing. SO no I do not believe you wasted their money. Now if it was a common failure and you have one in stock and don't "try" it you are wasting time and money. IMHO. Since you did not have one and obviously not common then I would say you did the…

+3 Default Ð Bounty Awarded
Andrew Technician
Commack, New York
Andrew Default
   

I think when we evaluate diagnostic approaches we have to keep in mind there are different measures of success: Was it the fastest we could have done? Was it the most reliable? Was it least expensive for the shop or customer? Was the potential for error minimized acceptably or well managed? I'm not saying that success can't be measured because it is too abstract, just that we have to keep…

+1 Default Ð Bounty Awarded
Geoff Diagnostician
Lahaina, Hawaii
Geoff Default
 

"Did I waste the customer's time?" Of course not! But you wasted yours when you grabbed a scan tool for that old pig ;-). 95% of what I see here doesn't have lights/signals computer controlled yet, so I chuckled when I read that, Mike,

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

Geoff, Somehow I thought that Toyota was so advanced. I remember working on Fords back before 2000 that had bi directional controls.

+1 Default Ð Bounty Awarded
Anthony Technical Support Specialist
Kirkwood, Pennsylvania
Anthony Default
   

Hi Mike: Don't conflate On-Board Diagnostics with On-Board Scan Tool Diagnostics. Asian vehicles were late to the game. A 2001 Toyota pickup had On-Board Diagnostics for Cruise Control, ABS and SRS. It didn't have On-Board Scan Tool Diagnostics though. They were "Blink Codes". BTW, late 2003/early 2004 is when Toyota started incorporating a lot of that stuff into the scan tool. I think NUMMI…

0 Default Ð Bounty Awarded
Brian Owner
Parma, Ohio
Brian Default
   

No you did not waste your customers time. I bet the next one of that vintage you will be at the hazard switch testing in no time at all, passing up the scanner for this problem. I am working with some shops that want to develop a "Standard Electrical Diagnostic procedure". This is to be followed when they have electrical problems , and a debate in my head has been whether or not to complete…

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

Hi Brian, When we get down to Brass tacks, electrical diagnostics is all about electrical pathways. Is there enough amplitude (volts) is there enough flow (current) or is there too much of one or the other or both. We as an industry have to change our own line of thinking about the value of our time. The perception of the customer is that the only valuable time is the time spent replacing the…

+3 Default Ð Bounty Awarded
Jordan Diagnostician
Roca, Nebraska
Jordan Default
   

I've always suspected this is largely a baby boomer issue. They weren't charged diagnostics with the cars they grew up with for obvious reasons Like wise the techs never got paid diag time. Decades later these techs own shops and don't charge diag. I expect it to gradually get better over the next several decades. On the other hand it opens up a whole new world for ethical issues. How many…

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

Hi Jordan, When it comes to ethics, we as technicians tend to sell ourselves short on our value. A repair is not done until the culprit is identified. If a technician uses best practices I don't see a problem with billing hours. Where I see a problem is where a technician reads the code and does not even look at the trouble tree for insight. There are pay resources and Google. You have to use…

+1 Default Ð Bounty Awarded
Jordan Diagnostician
Roca, Nebraska
Jordan Default
 

I think we're in total agreement Michael, of course free diag cost shops money but they do it anyway for numerous reasons. I do believe flat rate has a lot to do with that. If shop owners pay straight time for diag we would not see the wide spread tech abuse. I like your comment about best practices. With proper training and equipment diag is not so "FM" anymore. It's more 2+2=4. It's a…

0 Default Ð Bounty Awarded