82 supra w/5m-ge engine diagnosing? - Toyota Nation Forum : Toyota Car and Truck Forums

supra_T · 03-25-2006, 10:55 AM

I've been trying to get this car running properly and haven't had much luck. I want to know how to run diagnostics on it with the check connectors. There are two near the front passenger side fender in the engine compartment that I don't know what they're for or how to make use of them. In my wiring diagram book they're labeled the oxygen check connector (has one terminal) and emission check connector (has three terminals, VF, VB, E1 according to my book). My Chilton's manual talks about shorting T to E1 and using the check engine light, but there isn't a T terminal nor a check engine light? Also, it idles high at over 1200 rpms and the manual says I need a special service tool, do I really? It looks like it's just a plug for the emission check connector that can connect easily to a voltmeter so can I use something else?

Jeeves · 03-27-2006, 10:09 AM

What year is the Chiltons for? My 88 has a T and E1.

supra_T · 03-27-2006, 11:25 AM

The Chilton's I have covers 71-85 Celica/Supra model cars.

Jeeves · 03-27-2006, 11:50 AM

There should be another terminal block somewhere.
like this:

supra_T · 03-27-2006, 01:50 PM

I can't find anything like that unfortunately. I'm thinking maybe this model didn't have the ability to store error codes on the ECM? It has a 9 pin and 13 pin plug into it and none of the terminals in my wiring diagram book are labeled T or TE1. The E1 terminal is a ground, as it should be, VB looks like it must be the power because it's 12 volts, and VF varies around 4-6 volts with the car running. The O2 connector had a varying voltage under a volt when running.

Jeeves · 03-27-2006, 02:15 PM

If you have an ecu pinout you can short the "T" pin to ground, that's really all you're doing at the diag block. In that car, it may even be under the dash somewhere. In my subaru it was under the steering column. Other than trying to find a pinout, I'm not sure how to help.

VB IIRC should be +12VDC, vf should be a sensor lead from the air meter, O2 should be a varying signal as you've seen.

Doctor J · 04-26-2006, 09:13 AM

82 Supra with vacuum advance does not have self-diagnostic ability like cars with OBD 1 system. However, on this model you still can monitor the feed back system (oxygen sensor) and estimate air -fuel ratio based on this test results.