Car Ka 2003, Dura Tec (Lambda sensor with grey plug)

Hello I have a Ford KA that was running fine, I thought I would change the plugs, oil and air filter as part of a service.

Its really puzzling me as the car was running fine before and never had any issues.

Since I have done this, right away on the second start up the engine check light has come on, I just though I may have knocked a multi plug or something, when removing the spark plugs or the air box.

I run a scan on the car and its coming up P0030 H02S Heater Control Circuit B1-S1.( pre cat manifold one)

I checked all the multi plugs and connectors and all looked ok, I spent ages doing this and have wasted so much time, I just conceded that it must be just unlucky and the lambda sensor has packed up.

Or is there something I could have knocked? all looks fine?

I went to Euro car parts and they supplied me with a FAE Lambda 77253, the plug was not right on this so I has to use the old one, I fitted this and cleared the codes, the light cam right back on, same code P0030.

I quickly tested the multi plug that goes to the sensor and I am getting around
4.3v on the yellow and black wire, and 12v on the yellow and purple wire, these go to the white wires of the sensor.

Is there any other tests I can do?

Does anyone know these cars inside out and have an idea on the wiring.

Really gutted, thank you.

 

You should have a switched 12v supply for the 02 sensor heater, 2 grounds and a signal wire back to the ECM mate dunno why you would have a 4v feed! Have to checked the Ohms reading over the O2 heater, be 2 black or 2 white wires (sensor side)

 

P0030 H02S heater control circuit (Bank 1 sensor 1)

 

Known problem with aftermarket Oxygen sensors.
The resistance of the heating part is different and results in fault codes.

 

Thank you for your fast reply.

The sensor has, 2 white wires, a grey wire and a black wire. I take it the grey and the black are a trigger and an earth, I dont know what is what or how to test the trigger.

And why am I getting just 4 volts out of one of the feeds to the white wire?

Update} just found this http://www.lambdasensor.com/main/mcolours1.htm says the black is the signal.

Got a meter no sure what or how to test,? thanks all.

 

i have a very detailed description of the code put will not let me cut and paste to here mate i could send to an email address ?

 

Ok two whites are the heater, one will be a earth the other a 12v feed! If the black is the signal don't prope into it, the grey will be the earth for the sensor! If you are getting only 4 volts you must have a wiring fault! Do a voltage drop test, put muti meter reading volts onto the 4volt wire then to battery live it should read 8volts (4v+8v=12v) this would show you have a "voltage drop"

 

Ok so both the white ones should be 12v as they are the heater wires, sorry you say put the meter to volts then on the 4v (use the red lead of the multimeter) then the other lead (of the multimeter black) to the battery live? If they are both lives (positives) I won't get a reading as there is no earth involved, ? Or am I missing something? Thanks again for the reply.

 

No mate one white is live the other will be a earth from the control unit, you would need a wiring diag to see which is which, or you could put your black muti plug lead onto battery neg and probe into the car side off loom! The earth should read zero and the live should read 12v (or maybe 4v in your case) It don't matter which way meter is if it's wrong you will get same reading but with a - in front of the number! If you have a perfect circuit yes you should see 0 volts as would be no voltage lost