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Hi!

I know where my two-hole OBD "short me and I'll blink a lot" connector is on the driver side in that rubber protective dealio, that's not what I'm talking about here.

Do all 22RE engines have a DLC connector? For clarity I am asking if I have one of these:

DLC1.jpgDLC2.jpg

I looked all over underneath the hood in all the places I've seen suggested: Next to the strut towers, next to each of the fuse boxes (hood and cab), next to the EFI, under the steering wheel...

I know my MH is old at 1986 but it's EFI, so there has to be an ECU that allows me to read diagnostics while it's running.......... right? 

Sorry if this question is the dumbest thing you've ever heard! ?

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7 hours ago, Pretty Interstate Machine said:

Hi!

I know where my two-hole OBD "short me and I'll blink a lot" connector is on the driver side in that rubber protective dealio, that's not what I'm talking about here.

Do all 22RE engines have a DLC connector? For clarity I am asking if I have one of these:

DLC1.jpgDLC2.jpg

I looked all over underneath the hood in all the places I've seen suggested: Next to the strut towers, next to each of the fuse boxes (hood and cab), next to the EFI, under the steering wheel...

I know my MH is old at 1986 but it's EFI, so there has to be an ECU that allows me to read diagnostics while it's running.......... right? 

Sorry if this question is the dumbest thing you've ever heard! ?

No it is not real time like a modern diagnostic system it will only retrieve a stored code. It will be a rectangular box with a lid like your dlc 1. The codes are related to a series of blinking lights then read form a chart from many online sources.

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Yeah, I know about the blinks and videos and info are everywhere on that... I have a guy that says that if there's a Toyota ECU, the DLC connector is there, and I have access to VF1/TE2/E1, I can get more data. Maybe I'm going overboard but I want to see what comes over the wire. I just can't find it.

I know that I'm looking for something like what this hand is on:

Image result for toyota diagnostic dlc1

or it might be alone like this:

Image result for toyota diagnostic dlc1

again....just....I don't see it. 

related: what is the other diagnostic connector? the one that you don't short out to read codes?

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In the run of the Toyota motorhome they did not have a real time diagnostic output. OBD did not come about till 96 and it was limited. If you have an engine code it can be read other wise you will get nothing unless it has registered a code. The codes are numerous possibilities as long as it has logged one.  Most of the extra connectors are factory test use only.

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2 hours ago, linda s said:

Well I didn't know they existed but apparently they would be under the drivers side dash panel from 84 to 88. 

https://codes.rennacs.com/Petrol-Engine/Japanese-Korean/Toyota-Engines.php

Linda S

Thanks Linda, this is where I ended up (I had this page open when I made my post). I think I'm gonna have to get my head under the dash more...  or see if I can find connector 12.

@Maineah I respect your expertise and appreciate your input. I know 1996 was the introduction of OBDII, but prior to that some OBDI Toyota ECUs give data and I am determined to find out if I can access that somehow.

Edited by Pretty Interstate Machine
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My question, even if they do how are you going to read it? What are you going to use as a program? It is a data stream that needs something to decipher it. In 91 they had a rudimentary system The data link connector and its position were not standardized, nor was the data protocol meaning everyone had their own ideal on how to implement and access it. It was not until 94 and only CA vehicles had any kind of standardisation In 96 it became the OBD standard.  

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41 minutes ago, Maineah said:

My question, even if they do how are you going to read it? What are you going to use as a program? It is a data stream that needs something to decipher it. In 91 they had a rudimentary system The data link connector and its position were not standardized, nor was the data protocol meaning everyone had their own ideal on how to implement and access it. It was not until 94 and only CA vehicles had any kind of standardisation In 96 it became the OBD standard.  

Valid question.

Short answer: I plan to write the software myself, and I think I'm capable of doing so if I can find the wires that send data.

Long answer: I work with an embedded systems engineer, I know several microcode developers, and I'm designing a synthesizer from scratch. I also know a fellow that got data from his '92 corolla with an arduino (not a 22RE, I know). OBDII is not voodoo to read, and the earlier the system, the simpler it is going to be to read. Data streams are great. If there is one, I can almost be guaranteed it's not compressed which means we'll just get constant data from the ECU. There's also MyEngine which claims to be able to read pre-OBDII Toyota data, but I want to do more with the data than just display it, and I plan to build an information display into my dash.

If I succeed, I'll end up with something that resembles a modern dash cluster in a 1986 vehicle, which would be pretty cool if you ask me.

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22 hours ago, Pretty Interstate Machine said:

Valid question.

Short answer: I plan to write the software myself, and I think I'm capable of doing so if I can find the wires that send data.

Long answer: I work with an embedded systems engineer, I know several microcode developers, and I'm designing a synthesizer from scratch. I also know a fellow that got data from his '92 corolla with an arduino (not a 22RE, I know). OBDII is not voodoo to read, and the earlier the system, the simpler it is going to be to read. Data streams are great. If there is one, I can almost be guaranteed it's not compressed which means we'll just get constant data from the ECU. There's also MyEngine which claims to be able to read pre-OBDII Toyota data, but I want to do more with the data than just display it, and I plan to build an information display into my dash.

If I succeed, I'll end up with something that resembles a modern dash cluster in a 1986 vehicle, which would be pretty cool if you ask me.

Have fun and good luck. Yes OBD2 is simple to read because it is standardized. Toyota's injection system was based on the Bosch systems for its day it was very advanced.

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12 hours ago, Derek up North said:

You can find copies of the 1985 & 1988 FSMs online. I'd imagine checking them would give some indication if you'll find what you seek.

good call, I think I've located those and am digging through them now

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1988 FSM describes diagnostic connector as "check connector". 1985 FSM has a "check engine connector" for shorting T and E1, as expected (page FI-22), and then on FI-69 describes connecting SST 09842-14010 to the "service connector" to check the Ox sensor ('88 manual has a similar process). I wonder if this is where I should be analysing/pulling signal... has anyone ever run this signal through a logic/signal analyser or a scope?

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The O2 sensor is variable voltage in the 0 to 1 volt range, 0 lean 1 volt rich it is very active and responsible for setting the systolic ratio the voltage swings average out to the mix at 14.7 to 1 (theoretical ratio) that voltage is sent to the ECU for injector timing to alter the mix.This device is easley checked or read with a simple voltmeter. It is a simplistic device and it was not until the 90's they added heaters to overcome the inability to monitor the cold mix of a freshly started engine. You could read the voltage and produce a chart to give you fuel mix but depending on the rate it maybe unreadable to the human eye. If it has a O2 output connector it would have made sense because it would have been a very easy check of emission systems operation at the factory and again a voltmeter would have told them all they needed to know if it's active the system is working and that's all they needed to know. Most likely it would produce a square wave on a scope. I don't mean to be a know it all but many years ago I taught fuel injection for Bosch as a continuing education course lot has changed since then the newer systems are light years ahead of the old systems and capable of a head spinning output including freeze frame and recording if you can afford the instruments to read them. There is only one thing in a 22RE system that remains constant and that is fuel pressure some had a WOT regulator (vac operated no electronics) that slightly elevated the fuel pressure. 

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1 hour ago, Maineah said:

The O2 sensor is variable voltage in the 0 to 1 volt range, 0 lean 1 volt rich it is very active and responsible for setting the systolic ratio the voltage swings average out to the mix at 14.7 to 1 (theoretical ratio) that voltage is sent to the ECU for injector timing to alter the mix.This device is easley checked or read with a simple voltmeter. It is a simplistic device and it was not until the 90's they added heaters to overcome the inability to monitor the cold mix of a freshly started engine. You could read the voltage and produce a chart to give you fuel mix but depending on the rate it maybe unreadable to the human eye. If it has a O2 output connector it would have made sense because it would have been a very easy check of emission systems operation at the factory and again a voltmeter would have told them all they needed to know if it's active the system is working and that's all they needed to know. Most likely it would produce a square wave on a scope. I don't mean to be a know it all but many years ago I taught fuel injection for Bosch as a continuing education course lot has changed since then the newer systems are light years ahead of the old systems and capable of a head spinning output including freeze frame and recording if you can afford the instruments to read them. There is only one thing in a 22RE system that remains constant and that is fuel pressure some had a WOT regulator (vac operated no electronics) that slightly elevated the fuel pressure. 

well, these days you can just use a laptop or cheap single-board computer on an old system to constantly read the values and record/freeze them... we're talking like 50 bucks. technology is pretty amazing!

I'm planning on building something computer-assisted, like with a raspberry pi. so, I don't need to be able to read the gauge with the naked eye. I skimmed this image from another forum because it looks a lot like my pickup...the circled-in-green connector is the one that we're talking about, right?

80-fuelpump1_9be22d26eeee7e72e15ce9393bf47ff1ab045985.jpg

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2 hours ago, Pretty Interstate Machine said:

well, these days you can just use a laptop or cheap single-board computer on an old system to constantly read the values and record/freeze them... we're talking like 50 bucks. technology is pretty amazing!

I'm planning on building something computer-assisted, like with a raspberry pi. so, I don't need to be able to read the gauge with the naked eye. I skimmed this image from another forum because it looks a lot like my pickup...the circled-in-green connector is the one that we're talking about, right?

80-fuelpump1_9be22d26eeee7e72e15ce9393bf47ff1ab045985.jpg

Yes they possibly will supply a O2 output I could not say for fact I have never had a need to use them. You may find that the end of the connector is plugged with plastic pins making it a bit more difficult to probe them. With the single wire O2 sensors the output data is right there at the connector if that is what you are looking for. The yellow flat connector is something else not related. If you are trying to computerize this why not take the code output and make a chart of the listed codes?  If you like feel free to PM me I can tell you pretty much how this system operates I'm no computer geek that's for people that enjoy that stuff but I do know how all this fits together to make it happen.

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Okay so, like I said before, I respect your experience and your knowledge here. I'm repeating that statement up front here because I'm probably going to say some stuff that you already know and forgive me if I say it in a way that makes it sound like I don't think you know. Perhaps I'll fill in a gap (unlikely) but moreso what I want to do is make sure I understand everything that is going on and carefully identify the plan and the things I do know.

Established that:

  1. We've got a car and a bunch of things that have sensors and senders.
  2. The senders are basically wires with various voltages and resistances that we can read with a multimeter.
  3. The ECU acts as a multimeter for all those sources, and tracks them.
  4. The ECU sends appropriate data to other systems based on the data and also lights up dummy lights etc on the dash.

I have to assume there's a way to get the data back out. Starting with what we're now under the assumption started sometime around 1992, the DLC started streaming the data it's tracking as serial data. Like, you could connect a wire to TE2 while the engine is running, and plug it into a computer's serial port and watch the data come down the line. To a normal person this would look like garbage coming down the line. Example screenshot (computer nerds, this is not Toyota data): 

Image result for serial terminal garbage

Thing is, it would come down the line at regular intervals. The guy that decoded the data says it's really just a dump of every value that the ECU can sense a few times every second or so. I have the software he wrote. That's why I cling to the idea of it coming over some wire that fluctuates in voltage. Once this was formalized, we all know what it became: OBDII.

The realisation that I've (slowly, and I'm sorry about that) come to is that the data probably does not come from my ECU. It might come from one of the newer ECUs and give us OBDI data, and I was (still sorta am) hopeful that it will return something. One of my main thoughts was that if the TE2 wire is present but experimental, they obviously wouldn't want to expose that to the public quite yet. But since it's been 30+ years I doubt there will be many repercussions at this point ?

If it's not though? I can read anything (if I know how), and I can record it, freeze it, play it back or record it. Writing a software tool to do that is trivial...it's the hardware part that I'd need to make sure I had right. So basically I guess what this has become is that I'm building the equivalent of a flight recorder / black box for a 22RE. I'm including an "incident" button which would simply add a timestamp to the data so I can look back if I hear a weird noise or something, and it will also display the live data as it captures it (think "Prius information display").

So I guess now my question is, I should tap this data and bring it into the black box, but where? I'm not talking about reading the just "check engine" codes or just the Ox sensor, though that would certainly be possible with my idea. I want every bit of data I can grab.from the car and I want to log it roughly once a second (or more often if possible). Is it safest to do this at the ECU? If so, is there a sort of "ECU extension cable" that I could patch into, perhaps? Or should I run a pile of wires out to everything under the hood (this seems less good)? 

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The entire system is time based all of the sensors working together to set the amount of time the injectors stay open if you listen to one you can hear it buzz the longer it's open the richer the mix, it opens and closes rapidly so it's a square wave signal nothing but 0 and 1's. Everything but the fuel pressure is constantly changing. I know nothing of how the system deals with this data I'm not a software guy but something strobes the data input to set the injection timing. From throttle position to temp. to baro pressure to O2 feedback etc the list is long. Maybe you should research how the OBD2 systems retrieve info and find out how they did it to see if it can be implemented in the older systems there is a lot more information on the modern systems and at least the modern ones mimics the early Toyota systems. My 2011 Tacoma system is very failure all be it a great deal more complex.

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  • 2 weeks later...

okay, so it looks like I have no DLC connector anywhere - between chatting with some folks over at the yotatech forums and here I think my ECU is just too old. Since I don't have the data stream (or don't know where to get at it, it looks like we're going to build a passthrough black box solution. the upshot of this is I will get live data instead of "after the ECU has made a pass at it" data. there's another product, MPGuino, that accomplishes some of what I'm trying to do, just not quite with the interface I want. so I'll probably attempt to convince their code to cooperate with my own.

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