No Turn Signals/Hazard Lights

Hey Folks, full disclosure, I have a shop do a lot of custom stuff. I work on Tundras from time to time. I am human though and sometimes issues come up. I am trying to exhaust all avenues, willing to look for feedback from a group.

My customer brought in his low miles 2020 Tundra 4x4 TRD and wanted an NSV light bar and Morimoto XB lights, all the way around, along with an XD Reverse light bar. Customer dropped big money, everything must be perfect.

I was doing the installation and had to troubleshoot some things along the way. For some reason, the turn signals and hazard lights stopped working. Both inside the combo meter/cluster and around the vehicle. I can hear the click and everything else works, high beams, running lights, brake lights etc.

I took off the lighting and put the stock lights back on, disconnected the NSV light bar from the harness, no wires were cut or spliced, other than a tap in the back for the XD reverse light on one tail light.

Man, I have worked on German cars for many years as a dealer tech, Toyotas are pretty straight forward. Lovely in their simple design, although I hate Toyota wiring diagrams. They are obviously still fallible but I enjoy working on them actually.

Anyway, I have done extensive troubleshooting:

1- The fuses are separate and power many things, so power isn't an issue (I did check all the fuses). Grounds are separated too.
2- Power flows from the fuses to the combo gauge then out the turn signal switch or hazard switch (ON SEPARATE CIRCUITS and grounds).
3- I checked power at the turn signal switch. ~12v when off and zero when using the turn signal switch, which is how it's designed.
4- I did a fault code scan and got fault 1507 for an open turn signal circuit, cleared it but it's a hard fault.
5- did a couple battery resets, other cars sometimes it unlocks the wedged code doing this. Fixed a BMW cluster doing a power cycle before.

So all that leads me to believe the combo meter/cluster pooped the bed. Which sucks because I have to take it to the dealer and have a service advisor try to fleece me to replace the cluster.

I already talked to the local dealer "Yeah it's gonna be 3-4 hours to diagnose it" gimme a break buddy, I already diagnosed it. I am tempted to just tell them to replace the cluster because I am fairly certain it's bad. I wish I could point to a causation of the failure but I don't have an answer. I didn't unplug any ECM's live (of which I have done on cars in the past with no issue).

Of course my customer is unhappy and I will be eating the cost of this, wish I knew what I did wrong. If I have any advice about opening a shop.

So what am I looking for? Feedback, has anyone had issues with the cluster and fault 1507? Anyone seen all the signals not work including the hazard lights? Anyone replaced a Tundra cluster for issues?

Thanks for any feedback.

 

So I just finished installing Morimoto XB lighting all the way around on my 2019 TRD Pro. Found that the leveling motors weren’t functioning so I ended up troubleshooting and found that I botched the install a bit by not using the included pigtails to connect the turn signals from the vehicle to the Morimoto headlights. Turns out that is what blew the 15A HAZ fuse in the driver side kick panel. Unfortunately, I didn’t catch that the fuse was blown, connected the pigtails and while the leveling motor issue was fixed, my turn signals and hazard lights didn’t work. So, I reinstalled my OEM LED headlights and the same issue was present (now I knew it wasn’t the headlights).

Symptoms at this point were a lack of lights flashing at the signal bulbs (front and back) and a hyper flashing sound (even though my turn signal bulbs were good and I was using halogen bulbs, not LED). Also, none of the arrows on the gauge cluster (ie “Combination Meter Assembly) were lighting up. This was observed when activating turn signals on both left and right sides, as well as activating the hazard switch.

I ran a voltage check at the SA Meter-IG2, SA ECU-DCC (No. 1 & No.2, and HAZ fuses. Everything was good, on voltage and current. Then I ran voltage checks on the Hazard switch, which is pins 1 & 5 of the J127 harness on the back of the A/C control assembly. Lo and behold, no voltage. Continuity checks also failed. For shits and giggles, I did the same voltage and current checks at the turn signal connectors at the headlights. No voltage, no current. Continuity check on these also failed.

So I’m drawing the same conclusion as you. Voltage and continuity “before” the combination meter assembly (CMA) is good. Anything I’ve tested after, is not. The only thing I can do to narrow down results and confirm further is to these pins coming out of the CMA, which is more work than I’m willing to get into at the moment.

Either way, my truck is still under warranty and I’m taking it into the dealership tomorrow. I’ll circle back to confirm and let you know what they find.

Pain in the butt…we live and we learn right?

 

@MaverickXV
Just wanted to follow up because I said I would. I just received the follow up from the diagnostics conducted by my dealership and they confirmed that the Combination Meter is indeed at fault here. They also mentioned that the check they ran came up with the same fault code you saw (1507). So, you're conclusions are confirmed and you will need to replace the Combination Meter on your customer's vehicle. I don't know the exact part number and even using my VIN to check for it online at autoparts.toyota.com results in like 4 different part numbers. I'm sure there's nuance between the different Tundra trims for the 2019 and 2020 model years.

Anyhow, at least you know now where the problem lies. Best of luck!

 

@MaverickXV

Not sure if you were aware we had diagrams. Sticky'd on top of this page. I cant be of anymore help unfortunately. Good luck. https://www.tundras.com/forums/electrical.130/

 

Guess he joined for help and figured it out . Maybe he'll be back when he can't figure out another Tundra.

 

You guys rock. This is actually where I found these diagrams (in a roundabout "google" fashion) previously. Soooooooo useful. I hope Maverick gets what he needs.

By the way, the dealership tried to fleece me on the replacement work for the Combination Meter Assembly (CMA). Warranty claim was denied because I had the Morimoto taillights (I guess that's to be expected, despite it not making much sense) but then the service advisor told me the replacement would be the cost of the part plus labor. When I inquired about why I'd have a labor charge one day after the technician sent me the video clearly showing my dashboard was already disassembled in order to confirm the fault in the CMA, the service advisor said the technician put everything back together to wait for the warranty claim decision.

What kind of retarded-ass, idiotic, decision was that? So now you want your customer to pay an extra $600 in labor to swap out a part because your technician made the mistake of prematurely reassembling the vehicle without consulting the customer or without a claim determination? I mean damn. If they'd have omitted the fact that I had aftermarket taillights the warranty claim would've been approved. No sweat off anyone's sack. The dealership gets their precious labor/part revenue and the customer is satisfied that the costs don't have to be absorbed by them. So now, I'm forced into a position where I need to pick up the vehicle, drive it back home without turn signals, order the part, wait for the part's arrival, and then spend my time doing the replacement (which isn't a big deal, I like working on my truck). Not to mention, the dealer is out the money for the part because I would've paid them the cost of the part just to avoid performing the work myself.

I'm probably missing some forest for the trees here

 

Can somebody tell what this connector is for?
I am familiar with the Press to initialize Tire Pressure setting switch but not the other one I am holding in the foreground. Had this connection left over after installing the NSV Knight Rider light bar.

 

These trucks are pre-wired for different trim levels so it is common to find quite a few unused connectors for an item that your truck didn't come with.

 

I just found out about and downloaded the Ultimate Tundra Wiring Diagrams for my 2019. This is awesome, and should be all I need to find out what connector this is.