AMC ET-501 - Engine Computer Diagnosis in the 1980's
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- Опубликовано: 14 окт 2024
- We have it pretty easy now for diagnosing Engine Management problems. AMC on the other hand decided to make it hard, then release this handy tool to solve it. Lets go through the AMC/OTC collaborative effort that was the ET-501 Fuel Feedback System Tester, what comes in the kit and how it all works.
I have scanned and uploaded the manual for the tool to the Internet Archive. you can find it here: archive.org/de...
The 4 and 6 cylinder diagnostic ROMs have also been dumped and uploaded to the same place: archive.org/de...
(When burning them to now EPROMs, be aware of pin orientation!)
About ten minutes into the video I mention the later Bendix and Renix computers used in Jeep/Renault vehicles at the time for fuel injection. Neither do I own vehicles that use those systems or the diagnostic tools that were available for those near the end of AMC's life but I have been given access to training laserdiscs which discuss it and the MS 1700 diagnostic tool. You can find that here: archive.org/de...
Remember to follow me on "X" at @CelGenStudios to keep up to date on what I am doing and what might be happening in the next video.
I couldn't afford the expensive diagnostic tool for my '82 Corvette - so I made my own. One of the earliest GM-OBD systems and it ran at 160 baud, so we figured out that 2400 was divisible by 160 - 15 times faster. Used a simple transistor circuit to match voltage levels to RS232 on a bulky laptop and we were able to read everything, including sensor data at a rate of once per second. This was mid-late 90's or so. We even had map tables that filled out in the software. I'd love to see what they actually used to tune these vehicles!
I made a similar adapter for my Geo Tracker to use RhinoPower's real-time monitoring software. Not only is that not even available for free anymore, he became incredibly hostile when I surfaced with my solution that wasn't making him money. He's part of the reason why I retired the Tracker in favor of the Eagle: No protocols to use the diagnostic interface.
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You have GOT to watch the pole barn garage episode where Dalton revives an AMC Eagle.
Im pretty sure there's a hacksaw incident involving the wiring harness.
Truly though, hes hilarious and does an excellent job.
Really enjoyed your video!
13:54 We had commercial dishwashers that HP boards were loaded into and thoroughly washed prior to repair. 180F for 30 minutes.... or an hour if you wanted to drag things out. Also had a vacuum chamber to dry with. We didn't use it very often. Pull a 180 degree board out and blow it off. It is dry in seconds.
This is pretty cool, I've noticed many times on pre OBD II and I vehicles there is sometimes a diagnostic port labeled as such or just an obvious test point in the engine bay etc, and wondered how manufacturers used them, some vehicles you can jumper two pins and enable a self check mode, sometimes they will flash the check engine light to output codes, usually repeating two or three times, and usually having a code meaning no codes or faults, sometimes you had to connect your own noid light, I remember seeing them on Nissans, Honda's, etc, now I want to start looking up random vehicles to find out, just to have the knowledge next time I work on one, I'm a mechanic by trade, I work on Mercedes Benz, Porsche, Audi, BMW, Lamborghini, Maserati, Ferrari, to brand new Ford, Chevrolet, GMC, Honda, Toyota, Nissan etc to ones as old as the 50's to diesel, equipment, if it runs on gasoline, diesel, ethanol, methanol, jet A1, nitromethane, kerosene, electricity, solar, wind I can probably fix it, hell I repaired a water wheel once 😂 I love to learn new things, skills etc
My Tracker was like that. There's one jumper you added and the CEL would blink out either for no stored codes or for a different blink code for each logged fault. I have another tool here which looks super fancy and plugs into the OBD I port but in reality it just counts the blinks and has a stored message for each error blink it reads.
I think the beauty of that tester is the simplicity, just a very easy to follow pass/fail system. Great video :)
Nice video but it triggered some "diagnose PTSD" for me. I'm a Citroën lover and their equivalent of your tool was called "ELIT" and it may have been a small bit more advanced but it was the same kind of instrument. Made for the 80's cars and maybe a bit in the 90's. Now imagine they used an instrument like that on the 1991 Citroën XM. And on the top version there was not only ABS and injection. The Engine management system was a pretty advanced Siemens/Bendix system with...well, everything. Basically all the features of today and it was inter-connected to the fully computerized suspension. And just for fun, the climate control had early CANbus etc. Today I have the Windows based "Lexia" software, but yeah... Imagine your instrument on one of the most advanced cars of the 90´s.
GREAT video. I can tell you took a lot of time to do all this. I finally gave up on my 86 Eagle wagon and just bought a new Chinese carb. I haven't put it on yet, maybe this week. I had lots of cold start troubles which I think was choke related but I gave up. I haven't noticed any electrical issues but I will check my Duraspark connections.
Consider this. I fixed my bmw without a code reader or a bi- directional scanner. It had an electrical problem that tripped the modules …. And no google and I tube played 0% roll in the end I did it with screw drivers and in my driveway. Don’t matter how complicated it gets as long as your ground game is strong and realize a humane brain set all that up you can figure it out.
11:18 The National piggyback chip might be an NS87P50, which is a 48-Series microcontroller.
there aren't really going to be faults for a basic timing controller, faults come later when it's not just a product of inputs and outputs. the legislated faults (the CEL) are for emissions compliance and come with closed loop lambda control and oxygen sensors. those systems have to test every component during a drive cycle in order to prove emission controls are working
i have that system for my '85. its surprising what it can tell you.
It tells you very little.
OBDII is thirty years old now.
🙃
I feel old now. ;_;
With some fancier cars the computer diagnosis a problem with the engine that puts the car in limp mode
1996 is almost 30 years ago
0:10 Oh come on. You know the minimum is far less than six.
At least three, sure but looking at a 2015 Subaru I can count at least six.
Traction Control Module
Engine control module
Transmission control module
Fuel pump control module
Body Control Module
Air bag control module
There's also control modules for the console/radio, the dash control module and lets not forget the factory immobilizer, all of which talk over their own network/CANbus pairs and can throw the whole thing into chaos if you pinch a wire pair.