- This topic has 16 replies, 3 voices, and was last updated 5 years, 5 months ago by
.
-
Topic
-
So this all started with our 2014 Flex SEL having a check engine light come on probably last year. Read the code and showed PO141 Bank 1 Sensor 2 Heater circuit failure. Car seems to be running fine but its annoying because the remote start doesn’t work with the CEL on. (note: it seems to come and go as it pleases without having done anything to it at this point) I decide to change the sensor thinking/hoping that’s what needed done and the light went off, for about an hour came back. I kinda let this go for a while as it doesn’t seem to really effect performance.
Fast forward to now, we are going to sell the car but the light is still on. To this point I have tested the sensor by testing resistance through the heater circuit and testing the function of the sensor. I removed the cowl and tested the wires with a multi-meter for both continuity and resistance and both looked good. I installed sensor 2 in the other bank thinking maybe I installed the wrong one. I called my Ford dealership and talked to the service department about possibly being a PCM and he said he didn’t think that would be it as its not common but did admit I seemed to have it narrowed down to that direction. He suggested using a Ford sensor (I got the first one through NAPA it was NGK I believe) thinking that could be the problem. I did this on Sunday, unhooked the battery to reset the PCM and the light was off until yesterday afternoon when I asked my wife if the light is still off and she just looked and it was back on! It seems it almost has to be the PCM having some kind of issue right?
Another thing of note is that a couple years ago the car wouldn’t start and I replaced the fuel pump driver module (behind passenger side rear door) but it wouldn’t start another time after it was replaced only to then finally start and haven’t had the issue since.
-
Replies
-
The code is for the heater circuit. Check the fuse for that circuit and or check for 12v at the connector of the 02 sensor
Thank you for the reply college man. I have actually done both of those and they both look good. 12v is at the connector and the fuse is good.
Was the voltage measurement loaded (still connected to the sensor) or unloaded?
Any chance to look at the freeze frame to see what the ecm is detecting?
In general, a P0141 is looking at 3 things: short, open or excess current.
So I checked the voltage with it unloaded.
And when you’re saying the freeze frame, you’re saying from a reading from a scanner?
I borrowed a friend’s of mine’s Snap-On Verus scanner and am honestly not entirely sure if I am reading it correctly. If you tell me what I am looking for I can figure it out though tonight when I get home and look at it again.
Thanks again for the responses. I am hoping to get this sucker figured out without taking it to Ford.
Check it loaded if you can. Sometimes unloaded voltage measurements are unreliable.
For freeze frame, that is a snapshot of the data when the code is set. There should be a option on the scanner to read the freeze frame data. I’m not familiar wit the snap on so I can’t give you further pointers. In the freeze frame, look for heater circuit values.
[quote=”dtidman” post=203185]Check it loaded if you can. Sometimes unloaded voltage measurements are unreliable.
For freeze frame, that is a snapshot of the data when the code is set. There should be a option on the scanner to read the freeze frame data. I’m not familiar wit the snap on so I can’t give you further pointers. In the freeze frame, look for heater circuit values.[/quote]
So I need to test it when it is plugged in and the CEL is on? Should it be hot as well?
Also, not to sound like a complete noob, but what am I looking for when I test it loaded? Also What will I be looking for on the scanner? I’m not really a mechanic but I felt like I had it narrowed down that the wiring was good and the sensor was good. Appreciate allthe help I am just trying to understand for myself really.
Thanks!
[quote=”dtidman” post=203185]Check it loaded if you can. Sometimes unloaded voltage measurements are unreliable.
For freeze frame, that is a snapshot of the data when the code is set. There should be a option on the scanner to read the freeze frame data. I’m not familiar wit the snap on so I can’t give you further pointers. In the freeze frame, look for heater circuit values.[/quote]
Showing 13.6 volts on multi meter with car started.
Is the attached what you’re looking for?
Sorry for all the posts this evening but one other thing. Is that neither catalytic converter seems to be as hot on exit as they are on inlet
I also took a video of the scanner. Sorry it is sideways but looks like the O2 sensor is bouncing up and down when it is warmed up and running at around 2000 rpm.
[quote=”college man” post=203197]Lets see if the code stays off?[/quote]
Does it seem like that CAT is bad? That wouldn’t cause a P0141 right?
If the CEL is off, the scanner should show nothing. Try to get the freeze frame if the code sets again. The test for the p0141 is run right at startup. Cats would be p0420 p0430, but if you have a p0141 the cat test may not be run.
I guess what my problem is, is I have traced wires, checked the voltage and on the heater circuit power both loaded and unload. Checked to be sure it is grounding through PCM. I replaced the sensor (twice) last time with a OEM sensor and tested it to be sure it was working properly. the signal wires have continuity and no resistance.
So I don’t know what would be throwing a code other than possibly the PCM is faulty or for some reason the catalytic converter is messing it up.
Yes the code is off right now, but nothing has been done different so I have no reason to think it won’t come back again.
I do appreciate the help and tips
- You must be logged in to reply to this topic.