Continuing with my idling problem, I was working and having a look at the Oxygen Sensor today so as to see what's involved in replacing it, and also check its condition.
Found a great explanation as to why we need one and I quote
The lambda sensor is a galvanic cell (basically a battery) with oxygen atoms acting as the electrolyte. The snag is that it doesn't function at temperatures below about 280 deg.C. - so to get it working straight after you start the engine they fit it with a heater. As soon as you turn the ignition on it starts to heat up.
The is why you need heater wires to the sensor to heat it up. I found a really good article talking about Lamda Sensors at
http://www.answers.com/topic/oxygen-sen ... technology .
Testing the sensor can also be achieved by reviewing the following quote
Anyway you can check your Lambda sensor ...
If you have a digital multimeter you can check its voltage output
Once its warmed up its output voltage swings between about 0.2 - 0.8 volts
If it sits on 0v or up at 5v then its not switching and is faulty
Only use a digital multimeter to check this as an analog one could damage the sensor
The plug/socket for the lambda sensor is behind the centre console at the floor
As to the wire translation, the following quote applies
The plug on the fto side is
Red - Heater
Black - Heater
White - Signal
Black - Ground.....These are the wires that run from the fto loom to the lambda plug.
But once it plugs into the lambda the colours are as follows
Black - Heater
Black - Heater
Blue - Signal
White - Ground.....Just to clarify,these are the wires that run from the fto plug to the sensor itself.
In my daily life, I always practice the art of "Trust but Verify", and I am always concious of Murphy's as well as O'Brien's Law (Murhpy - if something can go wrong it usually will, O'Brien - Murpghy was an Optimist) . To verify the above, given that wiring numbers are not given in the above quote as confusion could exist in wiring the "wrong" black wire from the FTO Loom to the new sensor, I spent some time looking at the wiring diagram for the oxygen sensor and I can see that the following applies
Wire 1 is White - Signal
Wire 2 is Black - Ground
Wire 3 is Red - Heater
Wire 4 is Black - Heater
The following diagram shows how I was able to ascertain which colour wire is which. The alphabetic characters denote the colour, where as the digits denote the wire number. Correct me if I'm wrong please.
The following legend applies to the above diagram
is the symbol for a heater. Given that two wires or connections are made to this, its safe to assume that wires 3 and 4 are the heater wires from the FTO Loom.
indicates body earth point. hence this wire is ground.
denotes a fixed resistor. This is Signal.
See
http://www.talkingelectronics.com/CctSy ... mbols.html for more info - very usefull in confirming symbols. You will note that from this site, the Heater symbol is similiar to a "Non-Inductive Resistor", but if you look closely, the images are mirrored.
The workshop manual shows the following diagram of where the oxygen sensor sits. I notcied that there is a torque setting for the sensor as well. Glad I bought myself a torque wrench many moons ago
Looking down the length of the car from the front, you can see the sensor wires from the exhaust pipe into the floor.
Another view of the placement of the sensor, wire and gromet. The gromet was quite easy to remove, using a flat-end screw driver.
With the gromet removed and the cable out, it was quite easy to unclip the wire, which was unusual. Most plugs that Ive worked on recently took me 3-4 minutes to figure out how they unclipped.
The sensor itself shows that it has 4 wires.
The sensor itself had the only markings of
ND 065500-09820 11P hence I'm unable to ascertain its make or origin.
With the sensor plugged back in, you can plainly see the wire relationship on my sensor. Given the above, I suspect something is wrong, as the colours dont match up.
I have purchased a universal sensor (still awaiting delviery) from Australian ebay ( as per dstock's suggestion - onya !!
)
Ebay Link Here
The following was taken from
http://www.lambdasensor.com/main/mindex.htm . As can be seen, the wires show that the FTO sensor corresponds to the wire colours of a Toyota sensor.
As to the TCL question in my previous post, I think I have answered it with the following diagram
I do not have such a switch, hence I don't have TCL.
As to my previous post in this thread, can anyone answere the questions relating to TPS please.
It can be seen Im trying to do as much as I can in resolving my idling issue, and at the same time providing you with descriptive info from my investigations. Any positive and more importantly accurate feedback would be greatly welcomed.
Thanks
Tom