Entering Closed loop faster with $A1

[tkoforpresident]

roger that. I hope I left enough wire for us to splice into.

Will update tomorrow.

[robertisaar]

looks like the EGR connector has 2 brown wires in it, one is the +12V, the other is the ground used to control EGR solenoid 2. you'll need to follow the wires until the 3 spilt up to go the the PCM and use the one that doesn't split, or use a test light and roll the ignition forward and see which of the two will power the light if the other lead is connected to a ground.

[tkoforpresident]

thx for the help guys.

I don't have an air pump in my car and I don't really know where the ccp wire is located.

I just snipped my digital EGR wires because I deleted the EGR altogether.

Do you know which wire (there are 4) to tap into for the EGR?

[robertisaar]

took a look....

93 firebird 3.4: the EGR +12V, AIR pump +12V, CCP +12V are all hot with ignition on.

the AIR pump uses a 20 amp fuse, and i would pick that one if i had a choice.

i'm sure there are other circuits you could use, but the emissions stuff seemed easiest.

any that you know are easy that you want looked up?

[pocket-rocket]

Any red wire (not to be mistaken for red w/ a tracer, which I don't believe GM uses red wires with tracers) in the engine bay is full time +12v. Does your car have a digital EGR? Those have 12+ with the ignition switch in the ON position (off with key off and people adding heated O2s use it all the time, or so I've read), as does the ICM, I believe.

[robertisaar]

sure sounds like you grabbed from a constant +12V source... toggle switch would work, since it's such a low current, but kinda ghetto IMO...

you have a multimeter? or even just a test light? you should be able to find a switched +12V with either.

[tkoforpresident]

I was afraid this was going to happen...


So i got the sensor all wired up last night and much to my dismay this afternoon I went to start the car and the battery was dead.

My thought here is that somehow I wired up the sensor to be getting power all the time so even when the car was just sitting there all night the sensor was drawing 12v from my battery.

Let me explain again how I wired it up.

The reference wire obviously got spliced to the old o2 sensor wire. I ran the two grounds to the ground point located on the passenger side fender. I ran the 12v to the "red positive" junction box just below the ground point.


But I thought that only gave power when the key was in the "on" position?

did i goof up?

Should I check my wiring one more time to make sure I have them going to the right places?

And if that checks out what can I do? Maybe we can run a toggle switch to the 12v source that I can turn on/off whenever I need to.

Or maybe there is just a better place to get the 12v from?

Please, I need help.

Any thoughts?

[tkoforpresident]

got the heated o2 all wired up and turned the key "on" without starting the car. After a minute the sensor body was VERY warm, almost hot.

Looks like we got it right this time

Now, that doesn't mean I'm getting a good reference signal so tomorrow or the day after I'm going to datalog to verify a good signal and then ship it off to Ben so he can play around with the closed loop timers.

[tkoforpresident]

Looks like my days of early morning stall-outs will be somewhat reduced


I'll get to this in a few days, I hate rushing these things

[robertisaar]

sounds like a plan to me.

[tkoforpresident]

cool, so i'm good to go?

just run the 2 grounds to the ground point, the 12v wire to the junction box, and the reference signal wire into the existing sensor wire.

[robertisaar]

i'm fairly certain that the OBD1.5 3100s supply power to the heater circuit at all times the key is in the on position....

EDIT: confirmed.

[tkoforpresident]

can you believe I FINALLY got around to datalogging?

I found that it is the PASSENGER side o2 sensor being used by disconnecting the o2 sensors one at a time and looking at my data stream table. Disconnecting the drivers side sensor did nothing but disconnecting the pass side sensor sent it back into open loop and set an error code. Bingo.


I think I'm gonna go ahead an wire up this heated o2 sensor now that I know which one to replace. It's a good thing we did this test because I was under the impression that the drivers side was the one in use. The good news is that there is a 12v junction box and also a ground point located on the pass side fender which I can tap into. The junction box supplies power at key-on so my only question is whether or not that will be ideal for tapping into since you're really supposed to use a source that has power only when the engine is running. But that won't hurt anything will it? It's not like the sensor is going to overheat and melt right?

[CNCguy]

Just a confirmation, Marc is correct as usual.

LOL... I wish that were true. This is just a topic that I know quite well from building harnesses and helping customers. We have switched to using heated O2s on all of our harnesses. Pretty easy to add in when the harness is being built.

[tkoforpresident]

Thanks Marc!