[blackwasp]

Originally Posted by Rohan24

It was raining heavily ....

Don't worry, in my Abarth as well, have encountered the CEL multiple times when it rained overnight, I went through a puddle etc. The light went out after 2 days of dry days.

[Rohan24]

Originally Posted by blackwasp

Don't worry, in my Abarth as well, have encountered the CEL multiple times when it rained overnight, I went through a puddle etc. The light went out after 2 days of dry days.

Thanks, mate.
But I have driven it in the rain quite a lot over the past few weeks and even gone through waterlogged stretches, as its been raining cats and dogs in Bangalore lately, and it has been running fine.

P.s : Huge respect for you, for choosing the Abarth

[Rohan24]

Originally Posted by blackwasp

Don't worry, in my Abarth as well, have encountered the CEL multiple times when it rained overnight, I went through a puddle etc. The light went out after 2 days of dry days.

Well, what do we know!? You were right! Today morning, I started the car and the light had magically disappeared! I literally jumped in joy
Yesterday night, I opened the fuel filler cap and closed it tight. Started the car, and the light was still there. No idea how it cured itself during the night. Does it take some time to register? I didn't drive around after closing the cap last night.

Also, I have a long-ish trip coming up this weekend. Should I still go to the service centre and get it checked?

[blackwasp]

Originally Posted by Rohan24

Also, I have a long-ish trip coming up this weekend. Should I still go to the service centre and get it checked?

CEL or no CEL, always get car inspected before a trip. My thumb rule is to get the car checked in the ASS if going on a long trip, else a visual check up of fluids, tyre, wipers, etc. myself.

If you have a friend nearby who has an OBD scanner, you can hook it up as well for diagnosis. Else take to the ASS.

[Jeroen]

Originally Posted by Rohan24

Well, what do we know!? You were right! Today morning, I started the car and the light had magically disappeared! I literally jumped in joy
Yesterday night, I opened the fuel filler cap and closed it tight. Started the car, and the light was still there. No idea how it cured itself during the night. Does it take some time to register? I didn't drive around after closing the cap last night.

Also, I have a long-ish trip coming up this weekend. Should I still go to the service centre and get it checked?

It’s always a good idea to get it hooked up to an OBD scanner, just to see if there were any error codes. Depending on what pops up, it might give you an idea on some preventive maintenance to ensure it doesn’t happen again.

good luck with it!
Jeroen

[Rohan24]

Update : I'm at the service centre. Got the fault codes checked.
It threw up 3 codes :
1.P0030 - heating circuit error
2.P0324 - knock sensor circuit error
3.P03xx ( Couldn't see this one properly)

1. P0030 - It said it could be due to a wiring issue. Needs to be checked.
2. P0324 - I guess it's the same with this one, as I have read that the knock sensor rarely fails. Moreover, if it was failing, I would hear abnormal sounds from the engine, power drop, drop in fuel efficiency.

It mostly seems to be something with the wiring. They can't check and rectify it today apparently. So they've asked me to come back after Diwali. I asked him if it can be taken on a long trip, he replied in the affirmative.

[Jeroen]

Originally Posted by Rohan24

Update : I'm at the service centre. Got the fault codes checked.

1. P0030 - It said it could be due to a wiring issue. Needs to be checked.
2. P0324 - I guess it's the same with this one, as I have read that the knock sensor rarely fails. Moreover, if it was failing, I would hear abnormal sounds from the engine, power drop, drop in fuel efficiency.

It mostly seems to be something with the wiring. .

Good, you’ve got the codes. And as I said before, wiring is a very likely culprit.
Now the bad news: can be very tricky to trouble shoot! Good mechanics will have experience and usually know where to look/check first. Some manufacturers publish this sort data in their technical manuals/notes.

But it comes down to a very thorough visual inspection and unplugging all connections and cleaning them all, and all grounds.

Sometimes what works is to gently pull and tug the wires a bit in different places with the engine running. If the engine all of a sudden sounds differently you might be getting close to a wonky bit or wiring. Or throws the CEL out again.

Sometimes the mechanics might want to replace parts. Once done and the problem gone, double check if possible; put the old part in and see what happens. Replacing parts usually means messing with the wiring and the connectors. Which might be the real problem. Some of these issues can be solved by simply disconnecting/connecting the connectors a few time. (will get rid of dust / oxidation etc)

Good luck

Jeroen

[Rohan24]

Originally Posted by Jeroen

Good, you’ve got the codes. And as I said before, wiring is a very likely culprit.
Now the bad news: can be very tricky to trouble shoot! Good mechanics will have experience and usually know where to look/check first.
.
.
.
Good luck

Jeroen

Yes, I hope they mean to troubleshoot it at length, which is why they said they can't do it in a day. The SA asked me about any symptoms and after listening to all that, he too kinda narrowed down to the wiring.
Last month, I have been driving the car over really bad roads, really rattling it out. As a result of that, the left HL bulb connector had come loose. Could be that some other connector would've got loose due to the same. :/4

I would love to do this myself. If only I had some lifting bay, and knew where all the connectors are. As yet, I only know the positions of the MAP sensor, and few other connectors.

[FanaticOnWheels]

I have a VW GT TSI. While starting the car today and reversing it out of my parking lot, I noticed the check engine light was on. I was a bit worried. Stopped the car, turned her off and started her again - the light did not come up. Drove for about 7-8 kms for breakfast, Started her again after my food and left for office. The light did not come up.

Is this a sign of something potentially wrong? It is quite cold here in Pune, could it be a false positive for a cold start/restart test going bad? The car has done around 21K KMs, uses only Shell petrol and has been serviced on time.

[carboy]

About 4-5 days back, the check engine light came on in my 12 year old Swift & didn't go off at all. Was about to take it to the mechanic when I decided to google. One of the reasons mentioned was fuel cap not closed correctly. So I turned the cap further - and the light went off.

[Jeroen]

Originally Posted by carboy

About 4-5 days back, the check engine light came on in my 12 year old Swift & didn't go off at all. Was about to take it to the mechanic when I decided to google. One of the reasons mentioned was fuel cap not closed correctly. So I turned the cap further - and the light went off.

Good for you!
Yes, it is one of the many, many reasons a CEL could come on. It also, just about the easiest one you can check yourself in the space of a few seconds, as you did!

The fuel cap plays an important role in the proper operation of your car’s emissions system. On modern cars any fuel vapour are trapped and re-used, or at least not vented into the atmosphere.

Yours it appears, was just not tightened sufficiently. But it is part that wears, especially on its seal. So it is worth checking the state of cap seal. If it starts to become brittle and or deformed, time to replace.

Jeroen

[carboy]

Originally Posted by Jeroen

Yours it appears, was just not tightened sufficiently. But it is part that wears, especially on its seal. So it is worth checking the state of cap seal. If it starts to become brittle and or deformed, time to replace.

Where is the seal? Is it on the car side or on the cap side? I think even the cap threads are also not in a good state. It was creaking when I tightened.

[Jeroen]

Originally Posted by carboy

Where is the seal? Is it on the car side or on the cap side? I think even the cap threads are also not in a good state. It was creaking when I tightened.

I am not quite sure on a Swift. But if you take a good look at the cap itself and around the filler neck it should (hopefully) become obvious.

The creaking could also just be a bit of friction, as it does need to seal tight. You could use a bit of lubricant such as vaseline (anything that does not affect rubber)

Jeroen

[carboy]

So my check engine light has again been on for a month now. I have ordered a new fuel cap which I hope will fix the issue. However, I am facing a new problem. Occasionally, my EPS light doesn't go off after I start the car & power steering doesn't work. It keep the engine idling for a little while & then I shut it & turn it on again, most of the time, the EPS starts working again. Sometimes it takes more time.

I wondering if this is because of the small leak in battery caused by the Check Engine Light on? I only drive the car for short distances few times a week. So is it possible that the battery is getting drained by the power leak caused by the check engine light & if so, could that cause problems with the Power steering?

It's a 13 year old Swift.

[Swapnil4585]

I have the CEL on since many months and on scanning the error shown is P0037. Now the oxygen sensor wire on my car has been removed because a dog's leg was stuck in it and to free it, the wire had to be cut. I have run my car this way for 5-6 months and the only thing I noticed is the FE has gone down a little.

Now since the travel restrictions have been lifted to a considerable extent, my long highway trips have resumed and I have the first one scheduled at the month end. I intend to install a new oxygen sensor set (my car has an upstream and downstream sensor). Whether this work is done correctly or not and whether it gives rise to any new problem or not, will be understood in the 10-11 days before the trip and shall be resolved accordingly.

My questions -

1. Which sensors to buy? Boodmo price is 2800/- and my trusted spare supplier says 900/-. The OEM is Denso.

2. Is this is a simple plug and play type of work or more than that?

3. What issues may arise due to imperfect workmanship?

The car in question is the 1ZZ FE Corolla.