bank 1 o2 (50mv-950mv) - bank 2 o2 flatlined (430mv-450mv)?
10-11-2010, 10:16 PM
#1
bank 1 o2 (50mv-950mv) - bank 2 o2 flatlined (430mv-450mv)? Theres got to be someone who can help me narrow this down. Bank 1 is oscillating fine and bank 2 is flatlined. Comeon guys help me out. Whats your experiences? Or have you never had to fix this before
10-11-2010, 10:26 PM
#3
Also before someone says it...its NOT the extentions either because im not running extentions. Im using the 13111 vette o2s with longer leads.
What else could it be?!
10-11-2010, 10:32 PM
#4
Its not the o2. I swapped the o2s with eachother and the flatline didnt change sides! It stayed on the same side!
Also before someone says it...its NOT the extentions either because im not running extentions. Im using the 13111 vette o2s with longer leads.
What else could it be?!
Also before someone says it...its NOT the extentions either because im not running extentions. Im using the 13111 vette o2s with longer leads.
What else could it be?!
then you have a wiring issue somewhere...
the pcm will show a flatline of 450ish millivolts whenever it doesnt see a signal from the o2...
you should check continuity from the o2 harness up to the pcm..
the o2's show up in the Blue connector on the pcm...
I know that pin B(o2 high signal) is pin 66 and pin 69 on the 99~02 pcm's
I just did some custom wiring on my car involving a wideband simulating an O2.
10-12-2010, 09:48 AM
#10
continuity test usually involves a tone... there should be a mark on the multimeter that looks like a speaker or a volume symbol like you might see on your computer.
get a small piece of wire that you can use to put into the pins on the pcm(your tester leads are most likely too big to get in there...)
touch the positive test lead to one of the pins, and the other to your o2 connector pins...
if its passing through, then you will hear a beep from the tester
if it doesnt beep,, then you dont have continuity.
find a pcm pin out to verify which wires go to which pins.
get a small piece of wire that you can use to put into the pins on the pcm(your tester leads are most likely too big to get in there...)
touch the positive test lead to one of the pins, and the other to your o2 connector pins...
if its passing through, then you will hear a beep from the tester
if it doesnt beep,, then you dont have continuity.
find a pcm pin out to verify which wires go to which pins.
10-12-2010, 10:32 AM
#12
Hey thanks alot. Im gonna do this when I get a chance.
Just a quick question...I planned on going to the track tomoro. Car is running great and I cant tell that the o2s are making the car run funny. Im pretty sure I had this problem when I went to the track 5-6 times this year and car ran great. Do you think it will be alright to go tomoro? Will I be affected at WOT or is it just a stupid emissions thing?
I aprisiate your help big time!
Just a quick question...I planned on going to the track tomoro. Car is running great and I cant tell that the o2s are making the car run funny. Im pretty sure I had this problem when I went to the track 5-6 times this year and car ran great. Do you think it will be alright to go tomoro? Will I be affected at WOT or is it just a stupid emissions thing?
I aprisiate your help big time!
10-13-2010, 10:44 AM
#14
Im gonna get into the wiring hopefully on fri.
Let me ask you...what do you think its more likely to be? If it was the ground (black wire) or the 24v (red wire) wouldnt other things in the system be faulting? Hmmmm...unless theres a short in the bank2 harness it self. Other than that would it more likely to be the High and low (purple and tan wires)?
Anyway...im going racing tonight do you think ill have issues? I more than likely had this problem ever since I had the headers and have been at the track 5-6 times pulling off the time in sig.
10-13-2010, 01:47 PM
#15
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If wiping the codes didn't get it back, you're down to
electrical problems (PCM, wiring or sensor).
If you pull the connector down by the sensor end of
the harness, and run the motor at high idle, you should
see activity even without heater hooked up - hundreds
of mV at least into a DMM. You should see 12V across
the open end of the harness side connector heater
wires and that 450mV on the sensor pair. Let this tell
you if the harness is good up to that point.
electrical problems (PCM, wiring or sensor).
If you pull the connector down by the sensor end of
the harness, and run the motor at high idle, you should
see activity even without heater hooked up - hundreds
of mV at least into a DMM. You should see 12V across
the open end of the harness side connector heater
wires and that 450mV on the sensor pair. Let this tell
you if the harness is good up to that point.
10-15-2010, 12:45 PM
#16
I dont have a speaker on my dmm so I set it on the 200 ohms. I placed one test lead in the purple #66 pin and the other test lead on o2 harness end. Its reading about .4 ohms which should say that the wire is fine (continuity) correct? I did the same thing with the tan #26 pin and same result about .4-.ohms.
I have a hard time believing that the pcm is shot.
I have a hard time believing that the pcm is shot.
10-15-2010, 01:27 PM
#17
Well I put a test lead on the ground (black from o2 harness) and other lead to good ground on the car. It reads about the same as others .4ohms.
I did all this with disconnected battery.
I did all this with disconnected battery.
Last edited by senicalj4579; 10-15-2010 at 04:27 PM.
10-15-2010, 02:54 PM
#18
If wiping the codes didn't get it back, you're down to
electrical problems (PCM, wiring or sensor).
If you pull the connector down by the sensor end of
the harness, and run the motor at high idle, you should
see activity even without heater hooked up - hundreds
of mV at least into a DMM. You should see 12V across
the open end of the harness side connector heater
wires and that 450mV on the sensor pair. Let this tell
you if the harness is good up to that point.
electrical problems (PCM, wiring or sensor).
If you pull the connector down by the sensor end of
the harness, and run the motor at high idle, you should
see activity even without heater hooked up - hundreds
of mV at least into a DMM. You should see 12V across
the open end of the harness side connector heater
wires and that 450mV on the sensor pair. Let this tell
you if the harness is good up to that point.
If im doing all this right then the wiring must be fine. Im ready to start swapping o2s again this is driving me nuts.
10-15-2010, 04:36 PM
#19
I put in an extra o2 I had in the basement. Cleared codes. Still bank 2 floating around 450mv.
Im starting to think the tuner disabled something or or whatever he did that did this. Is it possible for someone to disable or set parameters,tables (whatever) to make bank to read flatline 450mv?
Im starting to think the tuner disabled something or or whatever he did that did this. Is it possible for someone to disable or set parameters,tables (whatever) to make bank to read flatline 450mv?
