10 pin ALDL to OBDII Connector

Thread Starter

passerby

Joined Dec 11, 2020
12
Good day:
Does this seem correct to you?

it's just going to be an adapter between a 10 pin aldl diagnostic port and obd2 diagnostic port.

Thanks
 

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Thread Starter

passerby

Joined Dec 11, 2020
12
Are they even compatible? I may be wrong but it seems to me OBD2 uses and interfaces with the CANBuss system and the very old ALDL doesn't even use that system at all, two completely different systems that wouldn't be compatible at all. https://en.wikipedia.org/wiki/On-board_diagnostics
Thank you for your reply.
we have this adapter for sale in the web even OP-COM has it. the only problem is, there is not any of this adapter in the country that i live. so i want to make one for myself.
 

shortbus

Joined Sep 30, 2009
8,190
After my earlier posting I looked into this more. It seems they do make them but it seems like it's more than just two connectors and some wire. Since there seems to be no *universal* adapter that works for all makes, each type of car seems to use something different. Good luck with your project. But if it was me doing it myself would be my last resort. Better to order one and wait rather than blowing up either the cars electronics or the OBD2 tester by not doing things correctly.
 

Thread Starter

passerby

Joined Dec 11, 2020
12
After my earlier posting I looked into this more. It seems they do make them but it seems like it's more than just two connectors and some wire. Since there seems to be no *universal* adapter that works for all makes, each type of car seems to use something different. Good luck with your project. But if it was me doing it myself would be my last resort. Better to order one and wait rather than blowing up either the cars electronics or the OBD2 tester by not doing things correctly.
I get what you're saying, thanks for the advice.
The problem is, the country that i'm living is under severe sanctions, so it's a quite a process to order one. Also my car has broken down for months, and again because of the sanctions and worst government, there is not any authorized workshop in this country and no one can find the problem of the car. the weirdest part is that no one of the mechanics have scanners to check the engine, they just have ecu faults check tools and there is not any errors for my car. This is the reason of my try to make one to be able to scan the engine with some software.
Look at this link whenever you have time, it seems to be just wires.
 

shortbus

Joined Sep 30, 2009
8,190
Again I may be wrong, since I never worked on or with an Opel. But back when GM cars used that type of port ALDL it used one of the dashboard lights to read the codes. You shorted out two of the pins and watched the light flash to get the code. Not all of the holes in the connector even had terminals in them. It's been many years since I even saw a car with an ALDL in it. Don't know if this will help or not but here is a link to how it was done back when ALDL was still used, hope it helps you - https://www.thirdgen.org/forums/tech-general-engine/241331-pulling-codes-dumbies.html

The idea that the original ALDL flashed a dash light is why I don't think the adapter you want will help you out. A modern OBD1 or OBD2 scanner is looking for something more than a number of pulses that repeat.

Even with or without ALDL or OBD the old time troubleshooting skills still work. The engine needs fuel and ignition to run. And the parts used when ALDL was used are only slightly above the old points and carburetor type engines.
 

Thread Starter

passerby

Joined Dec 11, 2020
12
Again I may be wrong, since I never worked on or with an Opel. But back when GM cars used that type of port ALDL it used one of the dashboard lights to read the codes. You shorted out two of the pins and watched the light flash to get the code. Not all of the holes in the connector even had terminals in them. It's been many years since I even saw a car with an ALDL in it. Don't know if this will help or not but here is a link to how it was done back when ALDL was still used, hope it helps you - https://www.thirdgen.org/forums/tech-general-engine/241331-pulling-codes-dumbies.html

The idea that the original ALDL flashed a dash light is why I don't think the adapter you want will help you out. A modern OBD1 or OBD2 scanner is looking for something more than a number of pulses that repeat.

Even with or without ALDL or OBD the old time troubleshooting skills still work. The engine needs fuel and ignition to run. And the parts used when ALDL was used are only slightly above the old points and carburetor type engines.
Thank you for the link, i've done this before and apparently, there is not any problem. That's why no one can find the problem.

Thanks for your help shortbus.
 

shortbus

Joined Sep 30, 2009
8,190
What are the symptoms your having? What model and year is the Opel? Does the engine rottate with the starter? Carburetor or injection? Have you ever seen it run or did you buy it to fix up? Are you getting a spark at the coil wire? I ask that last one because many, many years ago one of my friends did a tune up on his car and it wouldn't start after he got done. When checking things out he had left the distributor rotor out!
 

Thread Starter

passerby

Joined Dec 11, 2020
12
What are the symptoms your having? What model and year is the Opel? Does the engine rottate with the starter? Carburetor or injection? Have you ever seen it run or did you buy it to fix up? Are you getting a spark at the coil wire? I ask that last one because many, many years ago one of my friends did a tune up on his car and it wouldn't start after he got done. When checking things out he had left the distributor rotor out!
It's an OPEL vectra-A 1994 2.0i j89 5MT engine: 20NE and i have it at least for 8 years.

The car was working properly, but I didn't know that the spark plugs' wires have been torn in some places. Until I found out that i hear some spark sounds under the hood. I parked the car in a dark place and I started the engine, so there were at least 6 places on wires that had clear sparks. I said to myself, so I must change them but I didn't know that running around 15 km could end up in this mess.
I just drove for maybe half an hour and when I came back, I just let the engine run in idle to let the radiator jet fan to be turned off.
But suddenly I heard a spark sound again, that was way louder than the things that i've heard before, maybe like a small cracker. And then the engine went off by itself.

This was the last time that the engine was running without problem.

I've done lots of things that finally I've figured out that the problem is the volume of the gas that enters the combustion chamber. The volume of the gas is way more than normal, so it won't let the spark plugs to ignite the air/gas mixture.
How do I know that probably this is the problem? Because when i'm removing the spark plugs they are wet of gas, and also when i make them dry and clean, the engine starts flawlessly in milliseconds, but it stays on mostly for less than 2 seconds. As you can guess after removing spark plugs, again they are wet of gas. This is a new spark plug, but just look what happened to it for running less than 15 minutes after I changed them all.

I figured out that when the temperature sensor connector is disconnected, it makes the gas volume less than what it was but not enough to make the engine running properly.

what i've done:
1. I used the built in diag method of the car that you mentioned earlier, and there is not any failure. (it's the same procedure for the VECTRA A)
2. I've checked the temperature sensor spec with the factory datasheet by using a multimeter and it's working within the specification.
3. I've checked the throttle position sensor and it's working fine. and with gradual changing of the air valve, there is not any jump in the voltage during increasing or decreasing.
4. I've checked the Trimming Potentiometer, air temperature sensor and the wiper of the MAF sensor, they also work within specification. Even though the maf sensor's carbon has some traces of the wiper, but when I tested it with a multimeter, there wasn't any jump in the output voltage.
5. I've checked the resistance of the injectors and their input voltage, they were all as they must be.
6. I've checked the sparks of the spark plugs and they're strong enough.
7. I've checked all of the fuses and most of the relays, but not all of the relays because I didn't know how I should check some of them.

These are the things that I've tried. At least those that i can remember now.
So, i've come to this point that maybe i can find some issues with checking the data of the car with a scanner software. But as i mentioned before, apparently i have to do it myself, and i must find a way.

Currently beside of making an aldl to obd2 adapter, i'm struggling to find the compatible chip with the ecu of the car.
Because i can buy ELM327 obd2 to usb adapter here, so if it's compatible with the ecu and making an aldl to obd2 cable comes to a result, then i hope, i can scan the car with a software.

Thanks for following up shortbus
 
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shortbus

Joined Sep 30, 2009
8,190
Hi again, well it looks like you've tried all of the correct things. Have you seen this link to a download of the repair manual? http://vlj2011.serveftp.com/912-1006186.html

But suddenly I heard a spark sound again, that was way louder than the things that i've heard before, maybe like a small cracker. And then the engine went off by itself.
That one kind of gives me some pause. I couldn't find that particular engine online but am assuming it is an overhead cam engine. Is it possible that when you heard that noise the timing belt jumped a tooth? With the engine only slightly out of time, not enough to cause valves hitting pistons, it might give the intake valves opening when the injector is firing. Some of the earlier port injection systems used the heat of the intake valves to help both cool the valves and to better atomize the fuel. If the cylinder is getting the fuel out of time and not fully atomized it could cause the plug not to ignite it. Off the top of my head that is the best I can come up with, but will think and look some more. Long distance troubleshooting is hard.
 

shortbus

Joined Sep 30, 2009
8,190
Me again. A quick look shows the engine management(computer) was the Motronic ML 4.1.
https://en.wikipedia.org/wiki/Motronic At the bottom of that page there are some links that may help you.
One thing that stood out to me was; " Fuel enrichment during cold-start is achieved by altering the timing of the main injectors based on engine temperature, no "cold start" injector is required. The idle speed is also fully controlled by the Motronic unit, including fast-idle during warm-up (therefore no thermo-time switch is required). " Even though you said the temperature sensor checked out OK, the GM fuel injection systems use two different temp sensors. One is for the temperature gauge in the dash, the second is for the computer. So did you check both? If the one that tells the computer the engine temp is bad it may be giving the cold start (like the old time choke) telling the injector to give way to much fuel.
 

Thread Starter

passerby

Joined Dec 11, 2020
12
Hi again, well it looks like you've tried all of the correct things. Have you seen this link to a download of the repair manual? http://vlj2011.serveftp.com/912-1006186.html



That one kind of gives me some pause. I couldn't find that particular engine online but am assuming it is an overhead cam engine. Is it possible that when you heard that noise the timing belt jumped a tooth? With the engine only slightly out of time, not enough to cause valves hitting pistons, it might give the intake valves opening when the injector is firing. Some of the earlier port injection systems used the heat of the intake valves to help both cool the valves and to better atomize the fuel. If the cylinder is getting the fuel out of time and not fully atomized it could cause the plug not to ignite it. Off the top of my head that is the best I can come up with, but will think and look some more. Long distance troubleshooting is hard.
Hi shortbus
Thank you for the link, I've tried the link with different IPs and different browsers but i can't open it, i've attached what i got.

About jumping of the timing belt, no it's not the issue because i've checked the timing belt too. But i forgot to mention it. i guess it has been about five months that i'm checking different things, so it's definitely possible that i forget the things that i've done.

About ecu i guess the car ecu is a motronic 1.5 because as it has been mentioned in the wiki page and the datasheet of motronic 4.1 at the bottom of the page, it has been used from 1987 to 1990 but the car is for 1994, so.

About the temp sensor, no i just checked this one and i don't know where the other one is located. But i'm on it to find the second sensor.
This is the engine

I really appreciate your help and concern shortbus.
 

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shortbus

Joined Sep 30, 2009
8,190
1. I used the built in diag method of the car that you mentioned earlier, and there is not any failure.
When you say there isn't any failure, do you mean you got no check engine light flashes? If that is the case, no flashes at all, you didn't have the correct pins connected. The video you linked to he has a 12 pin connector, the 10 pin one is a different configuration -
10-pin ALDL connector pinout
ABCDE
KJHGF

12-pin ALDL connector pinout
FEDCBA
GHJKLM
from - https://en.wikipedia.org/wiki/ALDL

About the temp sensor, no i just checked this one and i don't know where the other one is located.
Looks like you checked the gauge sensor, they are in the thermostat part of water flow. The computer temp sensor is usually in the block near the cylinder head area, or sometimes in the cylinder head it's self. This is because the block temp is more consistent to the real engine temperature. Now all of what I'm saying is based on GM American engines, not sure how they do it in the EU.

I don't know if my writing is really helping or not but I'd like to see you get this running again.
 

Thread Starter

passerby

Joined Dec 11, 2020
12
When you say there isn't any failure, do you mean you got no check engine light flashes? If that is the case, no flashes at all, you didn't have the correct pins connected.
No, sorry, what i've done is using a paperclip like the way it has been mentioned here. And i had two codes, 12 that means initiation of diagnosis and 31 that means, it didn't get any signal from crankshaft sensor, but it's natural because the engine wasn't running.

Looks like you checked the gauge sensor, they are in the thermostat part of water flow. The computer temp sensor is usually in the block near the cylinder head area, or sometimes in the cylinder head it's self.
Thanks shortbus, I'll find and check that sensor too. Currently i'm reading about Motronic 1.5 and i've contacted with some companies that produce automotive diagnosis adapters and softwares. I hope i receive some tips from them too.

I'd like to see you get this running again.
Thank you kindly.

What about the link that you've shared earlier about repair manual? can you open the link?
 

scorbin1

Joined Dec 24, 2019
55
I think the no signal from cranskshaft error may be something to look at. Ive never seen this signal come up on a non-running vehicle in my experience unless there was a problem with the crankshaft sensor.
 

Thread Starter

passerby

Joined Dec 11, 2020
12
I think the no signal from cranskshaft error may be something to look at. Ive never seen this signal come up on a non-running vehicle in my experience unless there was a problem with the crankshaft sensor.
Thank you for your reply @scorbin1.
Yes, i thought the same at the start, but i remember one time that the engine was running for maybe 2 minutes, i did the diagnosis again, and it was just 12 and no more 31 or anything else. But The engine went off by itself after maybe 2-3 minutes.
 

shortbus

Joined Sep 30, 2009
8,190
And i had two codes, 12
The 12 is what you should have seen when connecting the correct pins, so your doing it right.


but it's natural because the engine wasn't running.
No the codes are recorded and then shown when you access them at a later date. The codes can't even be accessed with the engine running.

If the engine starts and just dies do to flooding with fuel, I'd say the crank sensor is good. Since that and the cam sensor is what triggers the cylinders to fire the spark. When ever I foudn either sensor bad the engine would not even fire or try to run.


can you open the link?
I couldn't open the link either, but thought it might have been my computer security stopping me. It does that on some sites.
 
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shortbus

Joined Sep 30, 2009
8,190
@passerby I put problems like this in the back of my thoughts and sometimes ideas come up later. I Thought about something you said in an earlier post, #9 -
The volume of the gas is way more than normal, so it won't let the spark plugs to ignite the air/gas mixture.
As I thought more on it, if we were working side by side I would have looked at the fuel pressure regulator and put a gauge on the fuel rail.

If the pressure regulator is bad or if the return line to the fuel tank from the regulator is blocked some where the pressure will be too much and the cylinders will get too much fuel. The fuel pressure regulator is one of those things that usually doesn't cause a problem but some time does go bad. The fuel rail to the injectors should, an again I'm going by how the US does it, it should have a port with a cap on it that you put a pressure gauge on. The fuel pump gives more pressure than the fuel rail needs, that's why they have a regulator and return line to the tank.
 

Thread Starter

passerby

Joined Dec 11, 2020
12
If the engine starts and just dies do to flooding with fuel, I'd say the crank sensor is good.
Yes, I agree. That's the way it is.
I couldn't open the link either, but thought it might have been my computer security stopping me. It does that on some sites.
How did you open it for the first time?! If you can tell me the name and the publisher i'll search for it.

About the pressure regulator or the return line, These are not the problem either. As you can see in the video I've opened the fuel rail and used transparent hoses to check the gasoline inlet and outlet flow and also I've checked the fuel pump for any malfunction too.
If you ask me, it must be an electrical/control issue.

Thank you @shortbus
 

shortbus

Joined Sep 30, 2009
8,190
How did you open it for the first time?!
I never did open it, I couldn't so I posted a link for you.
As you can see in the video I've opened the fuel rail and used transparent hoses to check the gasoline inlet and outlet flow
I haven't seen any video here like that. The only one with injectors is the one that the engine cranks but no fuel comes out of them. Just using a transparent hose to see flow won't tell you if the pressure is correct.
 
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