ALDL to OBD2

[Clarky5150]

May be a strange question but I have seen adapter cables from GM OBD1 to OBD2. I have a really comprehensive OBD2 machine and wondered if one of these would allow it to read my S4 or is ALDL to USB and laptop my only option?

[andydclements]

The Lotus Esprit ALDL isn't OBDII compliant, so it's not a case ofvsimply needing an adapter lead.

[Clarky5150]

Thought as much. Ideally I would want an ALDL to USB as I don't have a laptop old enough for serial port. Any clues as to the best place for them. Eastern shores wont be a problem as im not in too much hurry.

[Barrykearley]

You need a free scan or espritmon setup chap - it’s the only way of knowing if the TPS is set correctly. Without it being correct you may well never get 100% throttle - which is where the magic happens.

[Clarky5150]

I agree Barry. I need the interface though so any pointers for a USB version would be great.

[Barrykearley]

@internets is the cable man 

[sailorbob]

Regarding your original query it depends on whether the diagnostic tool / software  is capable of ALDL diagnostics (some of the professional tools are) and how the ALDL to OBD-II cable is wired. If both tool and cable are suitable then the next hurdle would be whether the Esprit is supported. I expect that it would not be because, AFAIK, its datastream is unique to the Esprit.

[Clarky5150]

Thanks Derek. Hope you are keeping well. Have you finished that Mister 2 yet?

[sailorbob]

I'm good thanks, the MR2 needs some attention with some recent niggles like a caliper sticking and intermittent door lock problem.

[Clarky5150]

Drop her off Derek. Ill sort your calliper/door lock and you sort my rich and lumpy running/ABS flashing on the Esprit lol.

[RobinB5]

@Clarky5150 did you ever diagnose the problem via ALDL?

 

[ScottyB]

Today I found an old Bosch OBD1300 scan tool for OBD1 and 2 that has multiple cables and connectors one of which is labeled GM ALDL.  I was excited and bought the tool. The GM ALDL is not even close to whatever the Esprit connector is. Doesn't match up with anything I can find. Dissapointed. 

[andydclements]

No point really though @ScottyB because even with a cable, as per my earlier post, the port isn't compliant / compatible to OBD11. / OBD1.

[ScottyB]

It was my understanding the OBD1 is the same as ALDL. What is this connector technically called ? All the ALDL I've encountered have flat pins. Not this. 

[NG5]

For anyone interested this is a video of how to make a usb interface cable for only about £10 that works fine with Windows 10.

The video is titled for the elan M100 but I can vouch that the cable works fine with the Esprit.

The power jumper was missing from the board that I bought even though it was on the photo on the ad but not a problem for me as I had some. but it's only a bit of bent wire anyway. Needs connecting to the 5v terminal.

https://www.youtube.com/watch?v=ZVsLD1eJP7Y

[eriks4]

I watched the video and was surprised by the suggestion to directly connect the transmit and receive lines of the FTDI chip. In other schematics that use a TTL Tx and Rx, a diode (e.g. 1N4148) and resistor (1K) are used between Tx and Rx and the connection to the ALDL line is the point between the diode and the resistor.

 

 

[NG5]

It surprised me too (although I'm no electronics expert) but it seems to work fine. I've been using it for over 6 months quite a bit and had no issues.

But having only 2 wires to solder made it dead easy to make.