I meant to say only the standard protocol (the description of what the standard pin arrangement does what and the data transfer rates) is available. Both the description and the cables to connect to both OBD I and OBD II data ports are readily available.
An OBD I (the DLC 1 connection on the...
EDIT:
I do think I saw this years ago, and again just recently; someone was selling his reader (it went in minutes). The comment was made that the guy who made these has stopped and has fallen off the planet. :(
Yes, a good quality photo would help reverse engineer it. It can't be much...
Well, that gets half my problems solved for me. Looks like it's up to me to carry water for the '93-'94 crowd.
@jpoole, FWIW, I think the difference between the OBD I and OBD II signals is the pulse output to the annunciator (combo meter). The raw sensor data stream should be the same, at...
@DirtyPepper @jpoole
Post #9 update:
The solution I thought was a Celica was actually a Corolla. Here's the link, from an Arduino blog, with details on how the OBD I data was captured and routed. User talofer99 included his code, along with revisions (nice guy, that). It's a long read, but it...
What would really be nice is a diagnostic tool like the Toyota techs have to connect to the DLC 1 port, so you can get the OBD I/II data in the engine compartment for adjusting/testing/tuning use. The cables already exist and can be had for $5. The same board for the dash display would work...
Apologies for highjacking your thread, but the perfect solution would be to create a board to send the OBDII and other desirable signals to, and then display that information.
Ideally you'd want to tap into the leads at the ECU terminals under the glovebox (which would be straightforward) and...
I know some have rigged a tee, or wye, into the transmission temperature sensor port and installed a second temperature sensor to run to a dedicated gauge. That's absolutely the easier solution, although not the most elegant, for sure.
However, in the immortal words of the imminent sage, Mr...
I haven't found a list of ODBII signals; I doubt one exists publicly. If it does, someone has backtraced it.
If I understand you correctly, the transmission temperature signal, as near as I can make out, is only connected to the high limit switch on the ECU, which is also connected to the...
There's a thread on it here (somewhere) and a post on it (for another Toyota model) I have bookmarked somewhere in my library (which may or may not be retrievable).
The idea is that the transmission temperature sensor signal is routed to a high limit switch on the ECU board logic. What needs...