A couple of DTC codes…

[davey]

Hey everyone, im back again with my 2000 ford fiesta.

Yesterday my engine light came on, and today i had a friend plug in his snap on diagnostic machine and it revealed the following:

1. Cooling fan (cant remember the specific error, or code, but it mentioned cooling fan)
2. P1530 – A/C Clutch Circuit Malfunction
3. P0420 – Catalyst System Efficiency Below Threshold (Bank 1)

I understand from the last code bought up, that its likely to be my pre-cat lambda which is playing about? This code has come up numerous times, and i believe it was because i had a breather hose problem which was allowing air to bypass the throttle and the engine was revving itself sometimes upto 3000rpm which makes sence as it would be allowing unwanted/unmeasured air into the engine hence the lambda was picking up incorrect oxygen levels. I recently did repair the breather problem and it has been fine since, so am i right to think i can now ignore the p0420?

As for the second code guys and girls, my vehicle doesnt have air conditioning what so ever, from factory. Where do i go with the p1530?

Topic

[college man]

p1530-short or open to ac clutch circuit.I know you say the car
does not have ac.But the wiring might be there.check for a plug
or harness.see if the fuse panel has a fuse for ac.pull it if it does.
as for the cooling fans.do they work?If you could post that lost code
that would help. after searching for the ac wiring and pulling the fuse.
clear the codes and see what comes back.before you clear the codes.retrieve
that lost code.

[davey]

Oops – already cleared the codes.

I have looked around and there is no obvious a/c wiring (im fammilier with it as i used to own another fiesta before that had a/c) i have removed and tested the cooling fan and it deffinatly works!

Apparently if i unplug my coolant temperature sensor, and start the engine, it will bring the fan on automatically as a safety feature so i will give that a go when i next see my friend (incase it brings the darn light back on!)

[EricTheCarGuy]

Here is the information you need on the catalytic converter code. A P0420 does NOT mean that you have a bad O2 sensor.

[davey]

I strongly believe the code was only bought up, because of the breather hose problem i had only recently repaired. My crank case breather was split and actually loose on the manifold end too, resulting in the engine revving up to almost maximum which made me decide to strip apart the manifold and find it, at the time not knowing what was wrong.

It has since been replaced, but my knowledge of this area (mostly related to ETCG videos i might add!) leads me to believe that the code was bought up because of the extra air (where the breather pipe was not connected) was making the engine rev itself upto 2000rpm like it did, but that extra air wasn’t accounted for and the ECU couldn’t make sense of the extra air being drawn in and the o2 sensor saying “hey, what the hell man!”

As said i have replaced the breather, and made sure it is secure both ends. Would i be right in saying it’s okay to go ahead and forget that code now? I mean obviously if it comes back, yes, it means something else needs looking into.

This code has flashed up twice since i have owned the car (and above being my explanation (and fix!!) of why) but i have found a peice of paper in within the service book which had the code written down which tells me the previous owner got it too, but never bothered to fix it.

Anyhoo, thanks for all the responses guys.
I will also apologize now if i seem to ask alot of silly questions/ask for reassurance, as im currently studying motor vehicle service and repair at college.

(p.s I did try to do what you did in the video Eric, of getting the two o2 sensor readings and checking if either one was way out but my friends machine was having a bit of a hissy fit so we gave it a miss)

[davey]

Sorry i forgot to add:

The catalytic converter itself is (must be) fine, as it passed the emissions test of the MOT which was recently done and all the numbers seemed to fit right within the middle of the limit.

Heres a screenshot, if anyone can make better sense out of it then me 🙂
[IMG]http://i902.photobucket.com/albums/ac224/_davey/20130130_210313.jpg[/IMG]

[EricTheCarGuy]

I don’t think the code has anything to do with the breather. If you watch the video you can see that the code is set because of the secondary O2 sensor readings that monitor catalytic converter efficiency. Also, your above test does not show NOx emissions. I guess they don’t test for those. In short, you could still have a catalytic converter problem. You can easily check the temperature as shown in the video to verify this. Make sure you’re running at 2000 rpm when you do for an accurate reading.

[EricTheCarGuy]

I don’t think the code has anything to do with the breather. If you watch the video you can see that the code is set because of the secondary O2 sensor readings that monitor catalytic converter efficiency. Also, your above test does not show NOx emissions. I guess they don’t test for those. In short, you could still have a catalytic converter problem. You can easily check the temperature as shown in the video to verify this. Make sure you’re running at 2000 rpm when you do for an accurate reading.

[Author]

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