I've done plenty of reading and even more searching...

But I still can't get to the bottom of this set of issues;

2018 SR5 TRD Sport
New to me at 38k, now at 58k
Occasional use in hot and sandy, as well as ice and mud.
No mods, other than puddle lights in the mirrors.
Completely OEM body and powertrain.
Clean title/no accidents or damage repairs.
0 unrepaired recalls.
New battery.

Last November, I was deep in the NV mountains and woke up to 15 degrees with ice and a foot of snow covering the truck. When I started the engine, there were so many lights on the instrument cluster that I had to take a picture so I could remember what it looked like, because I thought the temperature was causing the problems. PCS, Trailer Brake error, sport shifting disabled, and a couple more lights stayed on for a couple of days while I finished the trip and went home. This was the first of what became an annoying set of issues that I cannot understand.

Since then, the same set of errors, which I've noticed are a pattern among users here, has persisted. This past weekend however, things seem to have gotten worse. Now, the truck is extremely sluggish from a start. In Drive, it's as if the transmission wants to start in second gear from a dead stop and it feels a lot like turbo lag, as the engine needs to build RPM just to get the wheels turning. A 5% incline on gravel takes 3/4 of full throttle just to get moving. No sport mode shifting. Trailer error. On the freeway, other than no cruise control, the truck behaves normally/healthy. Off road the truck is miserably unlike it's former condition.

A bluetooth OBD reader shows the following - P0705 P1578 C1201 C1A50 C13A9 B1247

I went through every fuse, engine and passenger compartments, and found one dead fuse. It was 15A in row 11, right column, in the block under the dash and it corresponds to Power Outlet #2, if I remember correctly. That got replaced. Issues remain.

I cannot afford $275/hr for the dealership to deal with this. Whatever I can fix, with my tools and abilities, I would like to attempt. I just don't know where to start.

Please help.

 

Maybe the ABS module or wheel speed sensor.

 

^
Have you visibly checked the ABS sensors?

based on those codes I’d bet thats your issue

 

ABS sensor posts -https://www.tundras.com/search/6828587/?q=ABS+sensor&t=post&o=date&c[title_only]=1&c[node]=27

Rodents could of chewed a harness, that's been seen in here before.

Also battery terminals being a little loose will randomly cause this to happen.

 

Batteries and rodents are my bet... in that order... make sure the terminals are tight and run a load test on your battery!

 

"I was deep in the NV mountains "

Check your speed sensors. Very exposed. Doesn't take much to mess one up.

 

Thanks to all who've replied. Checking all ABS sensors later tonight. I assume that I'm just looking for mechanical damage, extreme corrosion, anything else obvious. I'll report back what I find and the status after I test drive.

Please keep the recommendations coming. This forum and the hivemind here are invaluable.

 

take a look at the sensors themselves, the wires going into them, and if you see nothing right away follow the wires best you can. I recall a thread on here where someone had a similar issue and its cause the wire got pinched and damaged by a heat shield

 

Thanks. Yeah, that's the best I can do. I've dealt with intermittent electrical issues before and I'm way too busy and committed to other things to spare much time now for the DMM and diagrams.

 

Are you still getting dash lights?

 

This diagram helps a ton, but also, get a bi-directional scanner to check the speed sensors.

I had a similar issue when I was "deep in Northern NV fly fishing" and "in the Yellowstone Backcountry in snowy weather." The frequency increased when I was back in AZ(northern AZ w heavy snow), and I eventually tracked it down to a front left speed sensor, with a bad wiring harness to the sensor itself.

 

Where are you located that the hourly rate at the dealership is $275?

My money is on a speed sensor.

 

I've never heard of a bi-directional scanner, but I'll search now. I considered buying the techstream cable and a 2 day sub, but I haven't read more than the occasional user here running one.

 

Last night I only had time to check the ABS wheel sensors, so a test drive will happen later today. Thanks for the chart. Looks helpful and I'm going to print that and keep it in the tool box.

 

Outskirts of the Bay Area, CA.

It seems like the collective opinion here is wheel sensor. That's where I'm going to focus now.

 

Update--

Last night I got under the truck and checked all wheel sensors. All wires were good, at least as far as the first connector. I didn't go any farther in the front than where the wires enter the engine compartment and no farther in the rear than where it looks like they join above the differential. I removed all and cleaned everything: each sensor, it's o-ring, and mating surfaces. No obvious damage anywhere. The driver side rear sensor hissed a bit when I pulled it out, which I thought was strange, like maybe there was some pressure in the area. They appear to be nothing more than a Hall effect type sensor, though I didn't confirm with a test of what looked like a magnet on the tip, but I guess I could maybe check continuity at the connector with metal near the tip. I don't know of any simple and positive test of the sensor and I imagine that most repairs are just replacing the unit and moving on.

All the mention of rodents and chewed wires has me thinking there might be something there, too. Tearing the dash apart to look for evidence of chewing seems like a nightmare.

Thanks to everyone helping me out. I hope we can find a fix.

 

I had a similar (but not exact issue). My dash was lit up like a Christmas tree. My code reader had identified my problem as the right rear speed sensor. I fixed temporarily with a new speed sensor, however after some time the lights returned but this time I could hardly get the truck to move. I unplugged the right rear speed sensor and it drove fine although the dash lights were very distracting. I ended up replacing the wheel bearing and that has solved the problem thus far. Finding someone with the correct tools to fix the problem was a nightmare.

 

What caused all of the dash lights initially? Was the truck SUPER sluggish from a stop, almost like it was stuck in second, or maybe even third gear? Which code reader do you have that showed the pass. rear specifically? New wheel bearing solved everything? That doesn't make sense to me. AHAHAH

 

I bought one of these a few months ago, I like it better than the TopDon scanner I had

$159 2025 LAUNCH Creader Elite OBD2 Scanner for Toyota Lexus, Full System Bi-Directional Diagnostic Scan Tool, All Reset Service Code Reader, Battery Registration,ECU Coding, AUTO VIN,Lifetime Fr-ee Update

https://www.amazon.com/LAUNCH-Bi-Directional-Diagnostic-Registration-Programming/dp/B0CDPKN3X4

 

Before tearing the dash apart, take out your cabin air filter and look for evidence of nesting. That seems to be a popular place for mice and it’ll only take you a few min.

 

I found this thread -
OFFICIAL: MY22+ Toyota Tundra - Throttle Lag/Hesitation From Stop Issue(s) - T-SB-0111-22
and it got me thinking about how my situation could be closely related to what they're talking about and the wheel sensors versus speed being reported.

When I'm experiencing the sluggishness and reluctance to accelerate, could it be that the wheels are reporting an incorrect speed to a computer controlling power output? Would one sensor and it's response cripple the system in this way? If the truck thinks it's actually moving faster than it really is, does the traction control (or another computer) shut things down to prevent wheelspin?

Another update:

This morning I disconnected the battery to do some cleaning and looking around in the engine compartment and when I was done, I reconnected the battery and went for a short test drive. 4 miles later, I get the beeping and the blinking and my stomach starts churning.

I now (still) have three lights. And I realized that I had not been entirely accurate in my initial post. I forgot to add the Check Engine light to the tally. The error messages and lights now illuminated in the cluster are -- Pre-Collision System Malfunction message, Drive Start Control Malfunction message, Trailer Brake Error message, and Check Engine lamp. I also have the steady amber triangle/exclamation mark and slowly blinking traction control lamp. None of these are new.

 

All I could figure is when I had all the flashing lights was the speed sensor was bad at first. I replaced the speed sensor and all was well for a good while (maybe a year or so). When the lights came back I figured the same and replaced the speed sensor again. This time it didn’t work and the lights stayed on. After a couple of days I thought my transmission had gone out because it would barely move at high RPM. I disconnected the speed sensor altogether and although the dash stayed lit, the truck acted as it should. No problems whatsoever other than almost every light in the dash flashing. After much research on this site I decided I was going to see if it was a wheel bearing. I bought a bunch of stuff I didn’t even need, but after I replaced the wheel bearing I plugged everything back up and I haven’t had any further issues. I have an Autel MaxiPRO. Like I said I didn’t have the exact issue you are describing, but it was similar.

 

I don’t believe this is your issue based on the codes you pulled. Reading your post has brought back memories of the nightmare I had attempting to figure out my issue. I was ready to replace my entire ABS system at one point. Nevertheless, if I remember correctly, this is the thread that ended up helping me solve my issue. This forum is a wealth of information that I appreciate each day. I hope you get your issues solved.

 

Thanks. I just read the thread you referenced and it's incredible to me how many years this set of issues has plagued Tundra owners. Each post sounds so similar that if you didn't check the dates, you might think you were re-reading the same thread.

I work for about a month at a time and this year has been exhausting. To have it down like this creates stress and anxiety, especially when I only have a short amount of time to work on it before I get sent out again. This truck is the nicest thing I own and it took a long time to get into it, so I really look forward to getting out and using it. I'm not sure I can throw money at wheel sensors, axles, bearings, etc. and gamble for a fix, but I may try looking in sensor holes with a scope to rule out excessive corrosion, or some other mechanical damage creating an issue with otherwise healthy sensors.

Next step might be getting a dealer to attempt a diagnosis. My scanner won't point to a specific wheel, for example, and if they're only going to charge me an hour of tech time for connecting their scanner, it might keep the cost down and let me spend a lot less to do the repair myself. Your Autel is out of my budget.

 

I’ve gone down several rabbit holes through the years and ended up selling a few handheld scanners I had and bit the bullet on the Autel. All in all my family has 9 Toyotas with close to 2 million miles. Minor issues across the board for the most part, but maddening nonetheless.

 

Have you considered just replacing the sensors one at a time? Sensor might look ok but be malfunctioning. Not sure how else you could test the sensor.

 

This TSB wouldn't apply to you as it's for MYs 2022+...

I believe you said you're a 2018.

 

Yes, my truck is 2018, but I'm desperate for answers and want to put in the work before I go begging to others for help. Also, what I took from that thread, at least in my mind, wasn't specifically 3rd gen. Being stubborn and desperate is a painful combo. I hate losing.

 

I really don't like the idea of throwing money or parts at a problem like that...

The C1201 code is a 'sympathetic' code to your other issue(s) that pushes the truck into 'limp' mode; which is why you're getting loss of power and weird shift points, etc...

Limp mode will cause the dash warning lights to pretty much all light up and then you'll have reduced throttle response and the truck won't shift beyond 4th gear (so no overdrive gears)...

Like you said, you have codes referring to speed sensors, you have brake system communication errors, and you have a code for TPMS communication error. Some have had these issues all resolve w/just a speed sensor fix; others haven't and had issues w/wiring or connections w/the ECU...

Unfortunately, I don't think you're going to get a clear cut answer; even from the dealer... They're gonna pull the same codes up and make recommendations based on the most likely and often least intrusive repair first and go from there. They won't even commit to you to that the diagnosis is 'absolute'. Here's an example....

Code: P0456 Small Evap Leak (order from most to least likely resolution)...

Most likely fix: Replace gas cap (seal is bad) $20
Not as likely, but cheaper fix: Remove and re-seat your existing gas cap or clean around the filler neck entrance

Next possibility... Vacuum issue w/Purge valve: Replace valve $80 OE / $45-$55 parts house

Still doesn't fix the problem, so next up: Wiring... $????

Still doesn't fix the problem, next up: Fuel tank pressure sensor; then vent valve; then charcoal canister... up to several hundred $$$ to repair!!!

A good mechanic would know how to troubleshoot and get you a more likely cause and definitive solution, but it will take some time IE>> $$ for labor to investigate... This is why a lot of us will start by throwing a couple of 'likely' parts at something up to $100 or so and take our chances.

However, this is not always the best or most cost effective approach...

Looks like folks have already made those 'first step' suggestions. However, spending a couple hundred on sensors and then still being in the same boat would frustrate the shit out of me... You've searched; others here on the forum have also searched for you as well (I'm sure of it)... If no one is giving you an absolute solution or a few guys aren't saying the same, 'yeah, had that and this fixed it', I think you may be better off having it worked on by someone who says, 'yes, I'm gonna charge you some labor to diagnose the problem' (and not just pull codes), but I'll stand behind my recommendations and own them one way or another and make this right for you once if you trust to me to do my job.... (guys and shops like this are few and far between, but when you find one they are worth their weight in gold; whether it's a Toyota dealer or independent mechanic/shop)

These kind of issues are the unfortunate by-product of everything being connected to a computer or a sensor or a monitor; more tech = more things to fail...

 

Thanks for that thoughtful reply. The kind of shop you're talking about must exist somewhere and it has to be a massive relief to find a crew like this. I will try the sensors before I pull hubs and look at bearings. If I look at it like I'm not throwing money at a finding a fix, but more like, every other repair shop would do the same along the troubleshooting path, then I'm still making progress toward a solution. I've gained some confidence reading and listening to others here who've gone through this already, so I'm at a place where I've now got an educated guess (thanks to this forum) and at least when I get to a shop, some work will be removed from their process and things might be easier.