Hi,

I have a couple of questions regarding the check engine light coming on.

But before that, the scenario is:

I just had the following service done on the van.

1. change sparkplugs
2. change wires
3. change fuel filter
4. complete fuel system service/flush

Took the van home without any lights on the dash turned on, this was on a Thursday. Did not drive it much that afternoon after the service and did not drive it much the following day (friday). Just drove within the city for these 2 days, not over 50km and did not go over 80kph. Then drove it on Saturday for about 80 to 100 km at 100kph to 120kph. Stopped at a rest area for about 10 minutes and started the van again. This is when I noticed the check engine light was on. The first thing I check was the gas cover. I though it "seemed" loose so I took it off and put it back on. I'm not sure why it would be loose as I always make sure I hear 3 to 4 clicks when closing it.

First questions is, if the gas cover was indeed loose would the check engine light just go off by itselft once the cover is tigthened? If so, how long until it is suppose to turn off? Should the lights have turned off immediately after tigthening the cover?

Second question. If it was not the gas cover that caused it to turn on, would the service that was done on the van be a possible cause for the lights coming on?

Thanks.

 

The check engine light illuminates when a problem is sensed by the vehicle's computer.

Things such as a loose gas cap, a faulty sensor (o2 sensor, etc...), faulty A/C pressure transducer switch, cooling fans stopped working, engine misfiring, air bag malfunction, etc...

There are many things that can happen to trigger your light.

1st thing, check it yourself by turning your ignition key on, off, on, off, on, off. Your engine light will start blinking, giving you the stored codes.

Code 12 = 1 flash, pause, 2 flashes; this means your battery has been disconnected at some point
Code 55 = 5 flashes, pause, 5 flashes; this means the test is over.

All other codes that flash between 12 & 55, record these #'s and then look them up in a Haynes Manual. Or, post them here and I'm sure someone can i.d. them for you.

As for your questions. When the gas cap is loosened up and you re-tighten it, the light will not turn off immediately. It will turn off once the computer is satisfied that all has returned to normal.

I don't believe the services you had performed would have triggered the light. A possibility may be that one of the new iginition wires has come loose from one of the plugs, but highly unlikely.

Best advice, do what I did. I purchased an OBDII code reader at Princess Auto when they went on sale, Got one for like $70 CAD. They are easy to use, it will read your codes, has a book to i.d. the codes for you, and the best part, you can then erase the codes and reset the light yourself.

If the problems persist, the light will soon re-illuminate.

Good luck, but don't ignore the problem either.

I own a 97 Caravan. The last time my engine lightcame on wasbecause my electric cooling fans at the rad stopped working, due to a faulty relay.

Eventually, I would have overheated in the summer when stuck in stop-and-go traffic.

 

I did the on-off-on-off-on and got the following codes:

1. P1648 - which according to most posts i have read on the internet was your battery having been disconnected. there was at least one or two posts which says it has somthing to do with oil pump sensor. So which is it? Battery got disconnected or oil pump sensor? Do shops disconnect your battery to change sparkplugs and wires and fuel filters and do fuel system flush? if they do, that would explain the battery got disconnected.

2. P0135 - upstream o2 sensor malfunction or something like that? is this expensive to replace? can i buy the parts and do it myself? is it hard to replace? I am not a mechanic but i am enclined to do things myself as long as i can find a detailed guide on how to do it.

Since I already have the codes from doing that on-off-on-off-on procedure, do I still need to go to a dealership or shop to have the codes read? I guess what I am asking is, are the codes given to me in the odometer accurate or do I really need a specialized scanning tool to give me more codes/information?

Thanks for any information you can give.