Chrushev

Hi everyone, here is a short summary of whats going on.

I have a 2003 Lancer ES (USA)

A month or so back I noticed my engine fans were full blast as soon as car got power (with key in at the 2nd position before you would turn the engine on). After doing some research it appeared that the engine fan controller went bad.

I ordered a replacement from here https://www.1aauto.com/radiator-cool...=754343&y=2003

as you can see they "guarantee" it will fit my Lancer.

I got the replacement, put it in, everything was great, fans started working as they are supposed to.

Fast forward 2 weeks, I drive out of my garage on a coldish (by california standards) late November morning and lo and behold after about 30 seconds or so check engine light goes on.

This is a 14 year old car and this is the first time it ever had a check engine light go on (85k miles all driven by me).

So I check the obvious things. Gas cap is tight, all fluids under the hood are in order, all levels between Min and Max marks, no leaks anywhere. Car runs fine.

After 2 days I finally got some time to take it to a shop to get the codes run. Now between this drive to the shop and when light first came out it has been total of 5 drives and about 40 miles driven. As im starting it up to go to the shop... BAM no light....

I take it to the shop anyways since the codes are in memory.. he runs it and it comes up with just one code... the following one: http://imgur.com/a/85wDH

He says this is the O2 sensor at the front. I did not mention that I recently replaced the fan control unit.

Now my questions are:

1) Is fan controller even able to set off Check Engine Light?

2) If it can, would it be that same code?

3) Any ideas what it means that the light was on for 2 days then went off all of a sudden? If fan controller can set it off perhaps the contact is not good to the 3 wires that plug into it?

4) If its unrelated to the Oxygen sensor/fan control module.. then what could be the cause? What else could that error code mean?

Thanks!

CrAnSwIcK

iTrader: (5)

No, the fan controller will not trigger any DTC's, and no it has nothing to do with your oxygen sensor.


The light comes on when the error is detected, once a specified drive cycle is completed, a certain number of times, and the error is no longer detected, the light will go out.

Chrushev

So what does that error mean then? Why did it come on?

CrAnSwIcK

iTrader: (5)

your front oxygen sensor is probably on its way out...

Chrushev

Whats the best place to buy one? Should I get one from the same place I got the Fan Controller replacement? https://www.1aauto.com/o2-oxygen-sen...1022788&y=2003

Chrushev

Also this page here says that the wiring can be the cause.... is it possible for the Fan Controller to pull too much current or create too much resistance to mess up O2 sensor wiring and cause this Check Engine light error? They are located somewhat near each other.

Thanks!

4b11slayer

I think there could be a dtc for fan controller module.

Will o2 cause issues with fan controller? Prob not.

That code is for a o2 sensor. B1s1 upstream pre cat primary what ever you wana call it.

9/10 when its a heater code, the actual heater element fails so the sensor gets replaced. You can always verify the heater portion of the 02 sensor is reveiving proper voltage with a volt meter.

Chrushev

Is the upstream sensor that this code is for this guy here (red square) - http://imgur.com/a/3GYrb

4b11slayer

Yes. If im not mistaken, only the top 02 sensor has a heater. Just replace it man.

CrAnSwIcK

iTrader: (5)

I do not know where you got that idea, but this is highly unlikely...if there was to much current draw, you'd have a short, and the fuse would blow...if you had a very high resistance, or an open, then it would be like that part of the circuit was not even there....otherwise everything is in parallel, with the exception of some lighting circuits. This is to isolate failures to a single branch of the wiring system to have little affect on the rest of the circuit. But remember that changes in parallel resistance have little affect on the whole circuit.

there is no DTC for the fan controller...there are several for incorrect coolant temperature, which could be related, but none specifically for the controller.

the DTC you provided refers to the upstream sensor in front of your catalytic converter under the car.

Chrushev

Would it be possible to get a picture of where it is and what it looks like? Do I need to get under the car to replace it? Would jacking up the car be enough or do I really need to get it up there?

CrAnSwIcK

iTrader: (5)

jack and stands should be fine...it's in the pipe just ahead of the cat. There's a boot on the harness, and the connector is inside the car.

Chrushev

According to this post its the sensor thats visible when you open the hood:

CrAnSwIcK

iTrader: (5)

yeah, ****...sorry...must have forgot which sub-forum I'm in...I guess had Ralliart in my mind...yes, that is your front sensor...my bad