Another Crank No Start | OBD2 No Comm + Xmas Tree Inst Panel w/Bonus ‘It hasn’t run in months’

No worries, was just checking.

 

When you mention wanting to be on the higher ohm setting…is that high as in 20k or high as in 2m?

 

when checking for shorts you typically want to be on the highest setting so in your case 2M.

 

Just subbing as I am curious for the final solution.

OP, love the screen name as well

 

Hypothetically speaking….if someone were to inadvertently test the powers instead of the 5v….using the previously aforementioned process…..what would the anticipated outcome or damage be? Asking for a friend.

 

You mean checking resistance with the circuit powered?

 

The battery was unplugged so that would mean no power… I hope? These were the steps followed:

Disconnect battery
Unplug all of the sensors
Meter to ohm setting
One lead on one of the 5v pins
Other lead on good ground

it came back with some interesting readings that made no sense….of course. Another derp moment.

 

I'm unsure of what you mean exactly but your not going to do any damage to a circuit by checking resistance with a meter.

 

Cool. We will leave it at that and I feel better knowing I didn’t damage anything. I checked resistance but instead of checking against the 5v wires, I checked it against the power wires. Now to go back and test the correct thing.

Thanks again for being patient with me

 

You had indicated when checking for shorts to ground I should see OL or a very high reading.

Zero isn’t high nor is it OL… and that is what I got for all 5 of 5v wires when testing resistance, with batt disconnected, meter on 20m ohm the highest setting, black on ground and red on 5v. Any time I removed one of the leads meter would go to 1, so it was making good contact I think.

 

This is with the sensors and PCM unplugged?

 

This is with the sensors unplugged, but not the PCM - I didn't see PCM referenced for this, or maybe I misunderstood. In compiling this response - and thinking I really had it all together with my pics and stuff - I see I left out the Canister Pressure Sensor on the Leak Detection Pump, which required me to disconnect IH1. Is IH1 considered part of the PCM or is there something else PCM related to disconnect? Seeing as I have to go back out already to retest, because I didn't take my complete set of notes with me last night. I swear I get on my own nerves sometimes.

Below are the pics of the sensors for reference. Would missing that Canister sensor be the reason all of the readings were Zero?


Secondary Air Injection switching valves - before I unplugged it




Throttle Position Sensor






CAM 1



CAM 2 hiding back there





Whoever designed the install of this accelerator pedal position sensor needs to be drawn and quartered.




Of course, I still have one more to go.

 

Apologies I should have been more clear, I didn't specify unplugging the PCM and sensors. But yes you essentially want both ends of the wire isolated when checking for shorts to ground.

 

Sometimes I stop thinking altogether when initially working with unfamiliar tasks. It is becoming familiar though, slowly but surely. Sidenote: I did take some of the acquired wire testing skills to rule out a few things on the Juke (the other non-running car); thank you very much for your help in troubleshooting the second vehicle you didn't even know you were assisting with

Back to the Tacoma - I beleive I had this all wrong so I'll make my way back out for a do-over, but it may be over the course of a couple of days. I did want to mention though, in researching testing for short to ground, I began reading up on grounding issues and the havoc it can wreak. A short video posted by Uhaul demonstrated how grounding issues can prevent your Uhaul trailer lights from working. I got me to thinking about how trailer lights never seemed to work when connected to the Tacoma. I tracked down spouse and he confirmed that at some point within the past 3 years, for any trailer pulled - Camper/Boat/Scrap - he could never get the lights to work. I recall him troubleshooting the plug and the trailer, but that was about it. That all being said, I see a diagram in the service manual showing locations of the ground wires on the frame of truck. I know I've seen a few of them; I was going to locate others and see about testing those. If anything, so I can learn about these as well.

Last, I also researched a bit on lightning strikes on vehicles, and found an interesting article noting that even an indirect strike can inflict damage. Pics of strikes go from the extreme where the front end of a truck almost melted, to a tiny mark that was barely noticeable. I went back out to the truck to look - still didn't see anything indicative of a direct strike.

Lesson Learned: Here’s What Happens When Lightning Strikes Your Car | AutoTrader.ca

Below is pic from article on how minimal of a mark a strike can leave.




In the article is a link that momentarily had me feeling defeated.
A small collections of ECU's from a vehicle that got hit by a lightening strike but not directly. : r/Justrolledintotheshop (reddit.com)




Thanks again for the assistance; I will get the short to ground tested again and report back in the coming days

 

Thanks - there is a WHOLE LOT o' rage in this gal right now, but I also like Rage Against the Machine so it seemed to fit. Hopefully, I can pick up the pace with troubleshooting so it doesn't progress like a chess-by-mail game

Stay tuned!!

 

Hello - looks like I will be the weekend warrior on this project for at least the next couple of weeks....and dammitalltohell if mother nature hasn't keyed in on it to start dumping buckets of rain I do have somewhat of an update, though. I was able to take the service manual available here - the one with all the hyperlinked sections - and consolidate it to a single PDF. This made search and recalling much more efficient, reducing time spent on "I know I saw this somewhere" by about 96.28% Almost immediately I saw correlations between the sections within the service manual to some of the things you were having me test. It was a fairly large OMG Duh moment for me. I see sections on the 5V constant voltage testing, circuit testing between the ECM and other components, plus a detailed process to troubleshoot CAN communication woohoo! The good news here is that I shouldn't need so much hand holding because the manual is pretty good at "put the black lead here and the red lead here". Plus, it will be easier to sound like I know what I'm talking about when I respond
I have several sections all printed and ready to go when the rain stops, including the resistance testing attempt from my last venture out there.

Thanks again, and I'll be back soon with some results hopefully. I seriously cannot wait for the day you guys tell me to try cranking it.

 

Hopefully you have the right manual, 14 is alot different electrically than the 05-06 manual that is commonly shared around.
Good luck

 

https://www.tacomaworld.com/threads/2013-tacoma-electrical-wire-diagrams.278185/#post-6900335

 

Actually - you are correct in that I have the incorrect service manual, but surprisingly, I actually took into account the manual being older and the potential for differences, but that can only get you so far. However, I do have current versions of the important wiring stuff right now, courtesy of the 2014 wiring diagrams you had provided at the start and info kindly provided by TnShooter. These are the ones I've been trying to work from:

2014 4.0L Engine PCM Pinout.pdf
2014 4.0L Engine Wiring.pdf

I figured it would be easy enough to correlate the wiring diagram (that I'm still learning to navigate) with a section in the service manual (test this wire and this wire with a picture of the connection).

Spoiler alert: It isn't.

First, my cunning plan is more time consuming (for me) than I'd hoped. Plus, I'm sure there are instances where the number of pins for any said connecter would differ at which point I may as well divide by zero. Last, even though the below example isn't too bad, the reality is that I'd continuously be questioning myself on the accuracy of what I did.








At this point, I need to just get the right manual. I recall searching for one in the beginning, without much success. Only the FSM will do, and rather than searching the Internet far and wide only to wind up with some half-baked version written in Sanskrit, I had read that service manuals and everything else pertaining to Toyota is available directly from the source via a 2 day / $25 subscription to techinfo.toyota.com aka 'TIS'. The price is more than fair, it's the right stuff, plus it is all in one place. I read the website itself is fairly antiquated just like me, so I'll probably feel right at home with it. Judging by the front page, this might just be a blast from the past.

I have assorted ways to automate the mountain of downloads if that is how it is still set up. Additionally, I came across instances of what others have done that I can use as a backup. Whatever I get to work - or not work - I'll post here. I have a packed schedule this week with my day job, so I'm not sure if I can do the TIS access during the week or not. I'm sure most everyone here has either the access or what they needed from it, but if there is anything I can take a peek at (legally of course) during the 48 hours, I'm happy to oblige.

At this rate, I may be able to test crank the Lonely Tacoma some time around the year 2032. Mark my words though, come hell or high water I will get this f*cking truck to run again. Might even unleash some anger and drive over a few things around here...once I figure out how 4WD works.

I'll be back...

 

Yeah, after 2008 the manuals were more web based.
Or at least they are much more navigable web based.

You’ll get it going.