No flaming please. I changed plugs two weeks ago and did a stupid thing. I started the car up after doing it (before I put the covers on mind you), and it ran rough. I immediately thought I didn't plug in the No 5 coil. Shut if off and damned it I didn't plug it in. Plugged it in and it ran fine. Check engine light stayed on. I did this same stupid thing a year ago and it went off a week later.

Took it to Autozone and they show no codes. Light is still on. Took it to a good mechanic I know in town. He said no codes, things are running fine, but couldn't clear the code.

I know why the light came on but it's annoying and I want it off. Car idles fine, runs fine, gas milage is fine, so I know it's running good. Do I have to go to a dealer and redfaced, have them clear the code?

I had a real bad plug on that No 5 (drivers side), by the way, but it didn't throw a code before my stupid mistake. The plug was oxidized, real bad. I have put 700 miles on it since the plug change and pulled that plug to check out the new one. Looks perfect.

Any suggestions for a shade tree mechanic?

 

The best way that might work is to Set a code for something else. Then have them clear that code and see if the light goes off.

The Volvo's will set codes and when it doesn't see the fault after so many times it will hide it in the regular side where it is read from.

If you had the Volvo setup it would see the code and you would be able to clear it.

Alot of times also setting a code then clearing that one will erase the code as well.

Most aftermarket scanners won't see the code once it is in the dormant stage waiting to see if it happens again.

I have had to set a fault many times just to get all the faults cleared.

The S40's are known for Ghost codes which is what I described above.

 

never seen a ghost code myself. but then again im using Vida. why would going to a dealer making you redface? afraid they might actually fix it? I find it funny ppl who hate dealers, they never take there car there. but in the end when you have a problem down the road and your mechanic cant fix it.. where does it end up?

 

There was ghost codes that come up on Vadis all the time when that was in use.
There is still some that come up on Vida.
You will have to go in through the extended diag. codes to see them.
Do you ever use the in car Diag to check what systems have codes?
If not then maybe thats why you haven't seen them yet.
In car diag will show a code present but you can't read them with Vida unless you go to the extended diag.

 

Yes i do use in car diagnostics, especially when doin a CPS, You can see every code in a vehicle, maybe you are missing somethin in vida.. what version are you running? Im not tryin to be a *** or anything, but you can read all of the dtcs, in Vadis the codes would come up xxx, but when vida came the codes are displayed, when you erase them and then do in car diag the are no dtcs present in any module.

 

I know what you are saying but there is some that when you only try reading codes they won't come up. But if you go to the extended diag. they will then show them.
Only had it happen a handfull of times but it happens.

The S40's would always set an O2 sensor code that you couldn't clear unless you set another code in the system. That is what was the real Pita.

We have 2 systems at work.
1. Is the 2005 version of Vadis.
2. The acshmaucher system.
Some guys in the shop also have handheld scanners.

On those cars I am talking about the in car said a code stored in the ECM.
Nothing would pull a code till I went to the extended diag.

 

only familer with Vaids, but that version is outdated, i do remember i had a car that had some DTCs in that wouldnt erase, called our FTS and he came down and his version would read the dtcs, i was getting a XXX code, i've never seen a chk eng light in my time with no dtcs with regular dtc readings.. not saying it isnt poss. i've never seen it..
I have seen a RASH of false DTCS on all 99-00 S/V 70's. The root cause is a voltage drop from the batter to the relay box power supply, so keep your eyes out.. When you get yor next car in, make sure you check for a voltage drop across the cables. not saying its the cause, but if you dont have proper voltage it will burn you. I learned this the hard way with ABS codes. who ever thought that a ABS code on a S70 wouldnt be a module.. I was losing voltage on startup and it was throwing ABS Dtcs

 

We have been doing battery cables on the S70's./850's for years already.
Been down that road already many times.

 

i done my first cable about 4yrs ago, but seen a rash lately, as in like 2 or 3 a day..

 

Same here.