DRL Failures, Locker Indicator Flashing, and Chasing Electrical Gremlins

OP: This is too much to read through, but it sounds like
you made progress. Do you mind summarizing what you learned about the cause?

 

OEM DRL board failure. Bad board. Lol. Toyota is just dicking around because they can't fugue it out. Playing stupid.

 

Nothing definitive. So far all I know is that Toyota doesn’t really know what the problem is. A lot of testing was done on the truck and found some signal noise at the ground circuit for the driver’s side DRL. They removed all of my aftermarket parts, one by one, and the signal noise remained.

I ended up opening up the headlight and testing the LED chips one by one and each of them illuminated. So the actual failure point appears to be the DRL driver mounted on the board. As far as the cause for the multiple failures, that’s anyone’s guess at this point. Realistically it’s Toyota’s job to prove the cause of the failure but they decided it was easier to just issue a blanket denial of warranty coverage based on “aftermarket parts”.

The truck has been down too much in the last couple months due to some gear install issues that had to be sorted out for me to want to spend the time (and $$) for further electrical diagnosis. I have had several offers to perform a higher level diagnosis on the trucks electrical system so I will likely take someone up on one of those offers later in the year.

This about sums it up.

 

Thanks. Like somebody else said, multiple board failures shouldn’t occur unless something is wrong. A power conditioner circuit might help, I think somebody mentioned that too. Sounds like you are on the right track doing some careful analysis sometime.

 

As of today there still has been no resolution with Toyota. There is a new issue with the truck related to the rear locker indicator that may be related to electrical issues on the truck. This issue is that the rear locker indicator begins flashing at start up (intermittently) ever since 5.29 gears were recently installed in the rear end. The shop that did the install already replaced all connectors and sensors in the rear end in the hopes that the issue would go away but it did not. They were informed of the prior electrical voltage signal noise in this truck and their current theory is that a voltage spike at start up is causing the electromagnet in the locker to engage briefly and not fully which is causing the sensor to throw the flashing indicator light.

Since this locker indicator did not start until 5.29 gears were recently installed, the shop is sending the truck out for electrical diagnostics tomorrow to see what is causing the locker indicator to flash at start up and immediately go away when the truck starts moving.

Hopefully their theory leads us to a resolution of what is causing the signal noise in this truck in the process of fixing the issue with the locker indicator. If it is something the shop did, they will repair it. If there is something found to be wrong with the original equipment on the truck, I will get Toyota back involved with the current shop's assistance.

 

Yup! At least we will hopefully get somewhere tomorrow and I can change the title of this thread to something more along the lines of F Toyota.....

 

Hi Bill, welcome back to the thread! Looks like your profile is still on private. Nothing worth while to share? Something to hide? I’d still love to see your truck and your awesome off road adventures! Over 6k posts, you must have plenty!

Cute, you went back and changed the photo too. Not even a good troll!

 

Just a thought for you if it ever does go to litigation. Take all the diagnostic plots and remove identifiers. Can the Toyota expert tell which is the real McCoy? The one without mods? If the answer is ambiguous or no... then show the plot from the reference truck and ask the same question.

 

Just curious, did you ever return your electrical systems to 100% stock and test if your problems persisted? It seems to me this would be the best approach.

 

Yes, that was done during the oscilloscope testing. In fact I paid the dealership to go through one by one and unplug each part and test after each pet was unplugged so I would know which part was causing the problem. They removed all the parts put it back to stock, and the signal noise was still there.

Toyota corporate still blamed “aftermarket part interference”.

 

Hmm, gotcha. Thanks for keeping this updated, I’m looking forward to hearing the outcome.

 

Well, they think they fixed the locker issue but it has nothing to do with the overall electrical issue. Apparently the pins in the rear harness to the locker were so loose that when it got cold they shrank enough to lose connection. The connector was re-pinned and circuit tested and it all checked out.

They are hopeful that this will fix that issue but it’s one of those “so simple it might not do it” kind of fixes. If it comes back they will do further diagnosis.

 

Spoiler alert....the locker indicator issue came back. Locker works fine, everything works fine, it just flashes super intermittently at start up. Very frustrating but I took it out on some trails today.



The shop is going to get back into it next week.

 

Well, we are at just about 1 year since the last DRL failure and that is 1 year with the Morimoto headlines installed without a single headlight/DRL related issue. This is clearly a failure on Toyota's part but at this point I have given the OEM Pro headlights (one perfect and one repaired by me) to a friend with a "TRD Faux" for free. Hopefully they are trouble free for him.

Also solved the locker issue that was a partial subject of this thread. It involved machining the locker indicator sensor flange down a couple thousandths of an inch to provide slightly more clearance. That, unlike the headlights, was definitely an aftermarket parts (5.29 gears) related issue.

 

Yeah, if you don't have any issues as of now, def seems like toyota issue.

Glad you got the locker issue figured out.

 

I say u get the old ones back and swap em out, just to be a million percent sure.

 

Which 5.29 gears did you install, nitro or yukon? I’ve heard that the yukon are better.

Glad that indicator issue was fixed, it made sense that it was only related to the re-gearing.....says capt hindsight!

 

They notated my Toyota Owners history blaming me and aftermarket wiring. Made it very clear this is the final replacement. Went through 4 or 5. Morimotos since and no issues.