check engine light on 1994 940 sedan Topic is solved

julesV · Post by **julesV** » 23 Jan 2017, 05:34

Hi. I am brand new to forum and I'm sure this question has been asked a lot. My check engine light been on now for about 3 weeks. I like to be a hands on type of gal. I have been reading about the usual issues that could cause the light on and hopefully it's not a serious issue. I have noticed that the past service records which were given to me with the car has not shown a very recent change of plugs. I would like to either change them myself, and also reading ALOT about what it could be. This is a very clean car with only 1 previous owner. How do I reset the light? I have watched some videos about what to do. And is unplugging the battery a smart fix or not so smart fix? My thinking is just to take it to the mechanic and have him tell me what it is.....However, I'm not a trusting soul and would like to know what I'm doing before taking it in! No offense, but mechanics see women coming. Is there an easy fix? As far as plugs, what is the best directions to follow to change them out? Owners manual or buy a manual that has the breakdown in everything. (forget what the name of the book is that you buy that shows every repair) thanks for all your help

lummert · Post by **lummert** » 23 Jan 2017, 16:14

Is the light just the Service Interval Reminder?

First on left is Malfunction Indicator light for diagnostics.

Third from left is Service Reminder Indicator. Comes on 10,000 miles (16,000 km) after being reset.

julesV · Post by **julesV** » 23 Jan 2017, 19:12

It's the check engine. I've looked at the owners Manuel. And it's big and red and continuous. I'll prob take it to the same mechanic that worked on it since it was a pup

julesV · Post by **julesV** » 23 Jan 2017, 19:28

I just want to know. Can I disconnect the battery cables to fix this issue and if I do that, which cable do I take off first? Positive or negative?

lummert · Post by **lummert** » 23 Jan 2017, 20:58

If you disconnect the battery cable make certain that you have the code if OE radio is still present. There are instructions available for the Volvo on board diagnostics.

I found this link at the top of the page:

https://www.matthewsvolvosite.com/forums ... =2&t=24944

julesV · Post by **julesV** » 23 Jan 2017, 22:46

Thank you for your help. Do you mean the code for the radio to reset after I've disconnected the battery? I have that code. I'm confused. Positive or negative pulled first? I think I have just about all my answers!!

lummert · Post by **lummert** » 23 Jan 2017, 23:33

Everyone says to pull the negative first.

On page nine of the document that I linked to has This: Erasing Diagnostic System Memory.

julesV · Post by **julesV** » 24 Jan 2017, 21:48

Thanks so much for all the info