[OleAvalon]

Curiosity question.

This thing, what is it and what does it do?:

On a search, I see people confusing it with the OBD2 connector (which is in the cabin under the dash) -- but what diagnostics are available in this alternate connector, and what diagnostic tool accesses its data?

 

[Old Mechanic]

Most likely Toyota specific with them having the access to the tool, not sure just my best guess. Typically OBD2 is mandated, everything else is proprietary, meaning manufacturer only. If I'm wrong someone will be here shortly to correct me.

 

[Vangm25]

As far as I know, it is just an old Toyota diagnostic port. I wanna say we used a Snap-On diagnostic tool that had that add-on but we only used it once and I am not sure what it did. OBDII at this point should do whatever you need so it is best to just ignore the port.

 

[BMR]

On the older Toyotas with OBD1, you would jumper the TE1 & E1 terminals in there to get into diag mode, where the CEL would blink out the error codes. You could also:


Force the fuel pump to run with KOEO (jumper FP to +B)
Read fueling corrections by probing voltage across VF1-E1 & VF2-E1
Read O2 sensor voltage signals across OX1-E1 & OX2-E1
Read ABS faults (jumper TC-E1)
Force radiator fans to run (jumper OP1-E1)

There should be a label on the underside of the cap denoting the terminal IDs. As time passed, some of the terminal positions were depopulated, so the function was lost.

 

[OleAvalon]

Thanks - especially to BMR. I might actually have future use for the fuel pump run and fan on capability (provided it's actually wired).

 

[zzyzzx]

I think one needs to understand that while OBDII is standardized, there is still a lot of non-standardized manufacturer specific extra stuff that's not part of OBDII standards. You need yet still another scanner, or a much more expensive OBDII scanner to do things like air bag, abs, key fob programming, and these functions would be different for different manufacturers. The standardized OBDII stuff has more to do with emissions.