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-   -   O2 sensor signal voltage range? (https://landroverforums.com/forum/discovery-i-39/o2-sensor-signal-voltage-range-42492/)

LRD2&ME Jul 22, 2011 12:07 PM

O2 sensor signal voltage range?
 
Does anyone have test procedures for testing the O2 sensors. Also what are the NORMAL Operating values of the O2 sensor signal voltages to the ECU? Looking for normal range voltage values for Bank 1 sensor 1 & 2, Bank 2 sensor 1 & 2. Reason I ask is because I had two O2 sensors changed out recently. Both bank 1 & 2 sensor 2's were changed. My fuel economy is still near 7mpg. Once in a while while driving I feel a surge of power and then it drops. When I have the A/C on, my engine power is near nothing. Alot of dull spots in the throttle. Wondering if my O2's are sending bad signals still.

Cosmic88 Jul 22, 2011 12:16 PM

If I help you out and give you the specific values you are looking for are you going to say I am trying to make you look dumb or that I'm pitiful in my existance again?

Shall I help someone in need though he expresses dislike for me?

:cool:

LRD2&ME Jul 22, 2011 12:20 PM

No of course not. That is history.

Cosmic88 Jul 22, 2011 12:27 PM

SWEET!! good man...

ok, your GEMS ECM supplies the sensing circuit with a 5v reference signal value. The return signal to the ECM can vary from 4.99v and down to .1... that return signal is what drives the ECM to alter the air:fuel via the ground signal to the injectors. MAF could throw off that ratio too if it's dirty or faulty...

The heater element circuit is 12v Pulse width modulated voltage.

Chris-bob Jul 22, 2011 12:32 PM


Originally Posted by Cosmic88 (Post 258779)
SWEET!! good man...

ok, your GEMS ECM supplies the sensing circuit with a 5v reference signal value. The return signal to the ECM can vary from 4.99v and down to .1... that return signal is what drives the ECM to alter the air:fuel via the ground signal to the injectors. MAF could throw off that ratio too if it's dirty or faulty...

The heater element circuit is 12v Pulse width modulated voltage.

Which wire has the 1.21 gigawatts...:D

Cosmic88 Jul 22, 2011 12:34 PM


Originally Posted by Chris-bob (Post 258781)
Which wire has the 1.21 gigawatts...:D

Not a NAS option... :D

Also the wire colors and connector diagram is Section A3 pg. 6 & 7

Connector C112 is Left O2 and C113 is Right O2. The ECM connector associated with the O2's is C1017.

Also, in the WM is says " if the wiring to these sensors is crossed the truck will startup and idle fine but when the sensors are warmed up to operating temp. you will get misfires and a rich mix on one bank and very lean on the other"

Is is possible your wires are "crossed"? I don't take that to mean the connectors are incorrectly plugged into the opposing sensor. I take it to mean that the harness wires are crossing each other like a badly routed sparkplug wire. ya know...

LRD2&ME Jul 22, 2011 03:12 PM

When I got the bad sensor two codes on each bank, I swapped them out with used O2 sensors that had the original connectors snipped off. I soldered the wires in accordance to color. I wonder if the problem is at the spliceing. Do not really see why it would be a problem though. I'll have to go out and check for signal voltage. In reference to the GEMS ECU connector layout. Is it true that the upstream sensors are nearest the exhaust manifold, and the downstream located after the CATS? Also on the ECU connection (C) (large red) pin #8, 17, 33, 34 show the sensors. Is this the signal in pin location? So a multimeter positive lead at each of these pins should result in O2 sensor signal, right?

Cosmic88 Jul 22, 2011 03:54 PM


Originally Posted by LRD2&ME (Post 258800)
Is it true that the upstream sensors are nearest the exhaust manifold, and the downstream located after the CATS?

...Also on the ECU connection (C) (large red) pin #8, 17, 33, 34 show the sensors. Is this the signal in pin location? So a multimeter positive lead at each of these pins should result in O2 sensor signal, right?

Yes upstream is closest to the source (manifold) and downstream is farthest, post cat.

Yes, in C1017 pins 8, 17, 33, 34 would be output signal pins. And for the meter, Depending on which part of the circuit you are probing and so long as there is a detectable signal being sent by the ECM and then from the sensor and the other meter lead completes the circuit then, yes.

LRD2&ME Jul 22, 2011 05:25 PM

Alright, look forward to checking this thing out tomorrow morning. Thanks for the info. PM me your address Cosmo. Heard you wanted sample rollers.

Travelor Jul 22, 2011 08:12 PM


Originally Posted by Chris-bob (Post 258781)
Which wire has the 1.21 gigawatts...:D

Properly pronounced as "jigawatts" - Thanks for the back to the future flashback :)

In Peace and Agape,
Trav...


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