ho2s voltage?
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ho2s voltage?
morning all.
I spent most of yesterday in the garage trying to trouble shoot my wifes van the check engine light is on and I had the codes ran and it said low voltage from o2. I done some checking and the voltage going to it is only about .06 volts on the grey and red wire. I haven't messed too much with the obd II system but I have played a lot with obd I, and on it that wire supplies five volts as a ref. voltage. that is all I had to go off of since the haynes manual don't say and the factory service manuals now are over 200. so I checked for that voltage up stream of there at the cts and it also was .06v am I supposed to have 5v and if so I think the puter is bad can anyone test just the computer if I take it too them?
thank you.
Ben
I spent most of yesterday in the garage trying to trouble shoot my wifes van the check engine light is on and I had the codes ran and it said low voltage from o2. I done some checking and the voltage going to it is only about .06 volts on the grey and red wire. I haven't messed too much with the obd II system but I have played a lot with obd I, and on it that wire supplies five volts as a ref. voltage. that is all I had to go off of since the haynes manual don't say and the factory service manuals now are over 200. so I checked for that voltage up stream of there at the cts and it also was .06v am I supposed to have 5v and if so I think the puter is bad can anyone test just the computer if I take it too them?
thank you.
Ben
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From: Virginia
ho2s voltage?
I thought the O2 sensor generated it's own voltage? Any voltage sent to it would be for the heating element that some of them have so it goes into closed loop faster. I thought the O2 sensor generated .8volt-.2volt, swinging back and forth. You need a nice digital multi-meter to check it.
If you do have the low voltage, then the O2 could be bad or, there is something wrong with the engine making it run lean or rich all the time(I can't remember if low voltage is lean or rich?).
If you do have the low voltage, then the O2 could be bad or, there is something wrong with the engine making it run lean or rich all the time(I can't remember if low voltage is lean or rich?).
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ho2s voltage?
I am not sure. I was thinking it worked like the cts and recieved a ref. voltage and depending on what the computer got back it would make adjustments accordingly. the haynes manual doesn't specify that it was just what I was thinking and I've been wrong before. it did tell me to check for .4v on one wire and if I didn't have it to fix the circuit to the pcm. and that was at the o2 disconnect. I am not sure this may be over my head but I don't have a very good selection of ford service departments to choose from so I will probably keep trying to locate the trouble if anyone can help I would surely appreciate it.
thanks franklin2
Ben
thanks franklin2
Ben
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From: Virginia
ho2s voltage?
Did you get a code 41? This is what my fuel injection book says is the code for the oxygen sensor voltage staying low for an extended period of time.
The book first says to hook a high impedence(meaning high quality) multimeter in parallel to the oxygen sensor, leaving it connected to the truck computer harness. Start the truck and run it at 2000 rpm for 2 minutes. After this look at the meter. The book says the voltage should swing above and below .45 volts. If the voltage stays low, unhook the hoses between the aircleaner and the throttle assembly. Take a propane torch, unlit, and open the valve on the torch and let the engine suck in the propane. The voltage on the O2 sensor should go above the .45 volt level. The book says if the voltage does not go up check the following:
Dist cap
dist rotor
sparkplug wires
ignition coil
sparkplugs
egr system
fuel pressure
intake or vacuum leaks
If you find no problems with these, replace the O2 sensor.
Here's the book I have http://www.motorhaven.com/customer/p...cat=126&page=1
The book first says to hook a high impedence(meaning high quality) multimeter in parallel to the oxygen sensor, leaving it connected to the truck computer harness. Start the truck and run it at 2000 rpm for 2 minutes. After this look at the meter. The book says the voltage should swing above and below .45 volts. If the voltage stays low, unhook the hoses between the aircleaner and the throttle assembly. Take a propane torch, unlit, and open the valve on the torch and let the engine suck in the propane. The voltage on the O2 sensor should go above the .45 volt level. The book says if the voltage does not go up check the following:
Dist cap
dist rotor
sparkplug wires
ignition coil
sparkplugs
egr system
fuel pressure
intake or vacuum leaks
If you find no problems with these, replace the O2 sensor.
Here's the book I have http://www.motorhaven.com/customer/p...cat=126&page=1
Last edited by Franklin2; May 25, 2003 at 10:38 PM.
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ho2s voltage?
that sounds like a nice book there. I don't know what code I am getting I took the van to autozone and had it checked they said it had a bad o2, that it had low voltage but didn't tell me the code. I wanted to test it before I started throwing parts at it because like you said in the last post could be quite a few things causing it to throw that code. I am going to do a little more checking on it today.
thanks again for all the help.
Ben
thanks again for all the help.
Ben
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From: Memphis, TN
ho2s voltage?
Don't just throw part$ at it. The HEGO may be fine and accurately reporting a problem caused by something else entirely. You can get the manuals on CD for a LOT less than $200 - check eBay or the classifieds here for the Ford/Helm CD. For each year, there's one CD for ALL trucks & vans, and another for ALL cars.
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ho2s voltage?
thanks steve83. I have seen the manuals on cd on ebay for that van but wasn't sure what all it covered and how easy it would be to use so I haven't ordered one but with your recommendation I just may do so and try it out thanks.
do you happen to know if the grey/red wire going to all the sensors in the obdII is supposed to have 5v on it that is my only question for right now because I think that it should and it only has .06v.
thanks again.
Ben
do you happen to know if the grey/red wire going to all the sensors in the obdII is supposed to have 5v on it that is my only question for right now because I think that it should and it only has .06v.
thanks again.
Ben
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Post Fiend
Joined: Nov 2002
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From: Memphis, TN
ho2s voltage?
Exactly what vehicle are you working on? My '96 CDs have OBD-II info and it says:
Signal Return
The Signal Return (SIG RTN) is a dedicated ground circuit used by most EEC-V sensors and some other inputs.
I checked the EVTM and found the Gy/R wire (pin #91) to confirmed that it IS the "Sensor Signal Return" circuit. Sounds like its voltage should be nearly 0.
Signal Return
The Signal Return (SIG RTN) is a dedicated ground circuit used by most EEC-V sensors and some other inputs.
I checked the EVTM and found the Gy/R wire (pin #91) to confirmed that it IS the "Sensor Signal Return" circuit. Sounds like its voltage should be nearly 0.
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ho2s voltage?
thanks again steve that is what I was looking for that is why it has the same voltage as the other wire on the hego. I was just thinking of it backwards, so the o2 does produce it's own voltage that means it is the o2 that is bad. good deal.
thanks a bunch to you and franklin both.
huge help.
Ben
thanks a bunch to you and franklin both.
huge help.
Ben
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