Entering Closed loop faster with $A1

[tkoforpresident]

I have a 3k mile 3500 O2 you can have for $15 shipped. You will have to unplug one of the O2s and datalog to see which bank it uses. John doesn't remember which side is the one to use. I have messed with the Cold start AF ratios but nothing fixed the cold start. I don't know how many tests were done on that though to date so that is probably what it needs adjusted still.

Thanks for the offer, I'll take it.

I'm at work so wait til I get home and i'll send paypal.

I'm sorry i didn't get more cold start logs for you to look at before i put the bird away for the season

[tkoforpresident]

money sent,

thanks Ben

[tkoforpresident]

Got the sensor today. Wires are two black, one blue, and one white.

My question is can I use this chart to figure out which wires do what? (It's supposed to be the universal diagram for 3100 and 3400 motors but i don't see why it would be different for the 3500)




Based off this chart that would make the white and one of the black wires grounds, the blue wire the o2 reference, and the other black 12V.


Anyone here with a 3500 haynes manual? If you went to the "o2 testing" section it would probably say which wires to test and that would let us know which wires are what.

thanks!

[tkoforpresident]

Then again...

Reading through the archives I found someone using a sensor with the same coloured wires and it was the two black wires that were grounds, the white was 12V, and the blue was reference signal.

That seems to make more sense but it doesn't correspond with the aforementioned chart.

[tkoforpresident]

I suppose i could just guess, but i'd rather not.

I needz some help plz

[bszopi]

I would go with the 2 blacks as being ground, white is 12V, and blue is signal. It doesn't make ANY sense to have 1 black wire be hot and another ground inside the same connector.

[tkoforpresident]

I would go with the 2 blacks as being ground, white is 12V, and blue is signal. It doesn't make ANY sense to have 1 black wire be hot and another ground inside the same connector.

That's kind of along what I was thinking too.

If there is two black wires (and black is usually ground anyhow) and the only two wires that are the same (same purpose) are the grounds, and if there is only one set of wires with the same color then i suppose i would have to side with reason on this one. But reason and GM don't mix sometimes haha

Thanks for the reassurance Brad.

[CNCguy]

I just went through this with a customer and it's just as your chart shows... "A" & "C" are grounds. I know the colors seem screwy but don't worry about that. One Black and the White should be grounded. The other Black is +12vt and the Blue is the signal. I think their logic with the colors is the blacks are for the heater and white is often a ground.

[tkoforpresident]

I just went through this with a customer and it's just as your chart shows... "A" & "C" are grounds. I know the colors seem screwy but don't worry about that. One Black and the White should be grounded. The other Black is +12vt and the Blue is the signal. I think their logic with the colors is the blacks are for the heater and white is often a ground.

Once again, GM fails to deliver sound logic!

lol...

Thanks for the information, it's greatly appreciated.

[bszopi]

Interesting. Thanks for the insight, Marc.

[Superdave]

Just a confirmation, Marc is correct as usual.

[tkoforpresident]

Thanks Marc!

[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]

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?

[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.