So does that mean this is a 22re ECM?
Any way I can fool the ECM into thinking I have a 4 wire sensor plugged in? My sensor is in the manifold so I don't see the need for a heated sensor, other than the ECM is looking for one.

 

Yeah it's the non turbo ECU, or at the least the cover is.

Your RTE sensor is in your down pipe, unless I'm mistaken and you don't actually have a stock setup, but I digress..

I don't know off hand what load the Ox heater provides but I'm pretty sure the HT line is a drain (switched ground)

Personally I'd be trying to source a correct ECU, looking at the pin map above indicates you would need to move some pins around. Since you got the vehicle as it is it would be a good idea to trace and label everything in those ECU plugs there's no telling that they are in correct position.

Let me poke around on HT details and get back with you.

 

A little poking around says it should be a max of about 2amps..

Maybe try this lamp trick..
"Whenever I diagnose electrical problems, I like to develop a quick and simple way of testing the circuits, if possible. When testing the O2 sensor’s heater circuit, I found using a #7440 incandescent light bulb and socket very helpful. You connect the light to the vehicle’s O2 sensor heater harness in place of the sensor. The light bulb draws about 1.75A at 12V. This is usually within the operating range of the sensor’s heater. This works very well—about 95% of the time."

So you'll wire up a lamp socket, supply fused and switched (convinent it's right there at the ECU) positive and connect the ground side to the HT on the ECU. Now the ECU will see the load it's expected.

The other option is just a current limiting resistor. Something in the five to ten ohms range (I didn't do the math on this, find an ohm's law chart or calculator).

I figure the bulb and socket will be easier to mount and deal with than a resistor.

 

Any multimeter test I can run on the box without cracking it? I'd like to avoid cracking open the ECM box since the truck still runs. This box has ALL the pins, but I don't know if that's indicative of anything.

The TURBO light still works, if that means anything.

I like this option. I'll give that a shot.

 

Given that the cover(part number) says it's an RE, and it outputs two digit codes. It's an RE not an RTE computer, I am very certain.

The RTE's TIL (turbo indicator light) shares the same pin port as the RE AS vsv, so that would explain why your dash light comes on. There is no boost gauge on the analog dash models and no boost sensor, unless someone can prove me wrong, the ECU outputs to the dash light when it thinks there is boost.

If you have the OEM boost sensor it's located on the fender and fed manifold pressure via the gas filter at the rear of the upper plenum.

Not aware of any tests you could do with a meter that would give any more proof than the two digit trouble codes already do.

 

Well that makes more sense now that I know what a VSV is. I always thought this turbo boosted a little early.
And mine's an 86, so it shouldn't have a boost sensor, AFAIK.

Also, since my ID plate under the hood states this engine is a 22r-tec, will any 86 22rte ECM work? If I remember correctly, California emissions trucks had extra vacuum hoses for extra emissions control, not ECM-based emissions, correct?

 

What is the full model number, can look up the computer with that.

 

 

Rn61l-mbza
89661-35050

 

Thanks!

Would the ECM be throwing knock sensor codes since the detonation is different on turbo vs. na engines?

 

Will look in the TCCS book and parts lists when I get home. I think they all peak at the 7khz range