Service Engine light on my 96 LS
 

HY Guys

MY Service Engine soon light came on today. I was at a barbeque with friends on my way home the light come on.
The car runs the same! I dont hear any strange sound or things like that.

Does anyone have any kind of help for me? I dont realy like the thought of bringing it to the repair shop and pay much for something I could fix myself.

The car is a daily driver and has been recently checked by the GM - Garage.

I have no Scan tool or things like that.

Ps: The car has the 3.1L V6 and is a 96 Monte Carlo LS, 139'000 Miles.

Thankful for any kind of help :(

If you have OBD-II than you should be able to go to an autoparts store and get a free code reading. We can't help you at all unless we know the code that is being thrown.

HY
I will try that tomorrow but I wont get it for free, I'm in Switzerland :-)
I hope I find someone who can help with the OBD2 reading, american cars arent so popular where I live.

Oh I didn't see you weren't in the US. Can you order a scanner online or would it be too expensive?

I know over here they sell some for only around $40 USD, could pay for itself if you are going to have the car for a while.

Its really hard to say, it could be lots of things.

More common things that sometimes cause light that are not always super noticable are the Mass Air Flow sensor, cleaning could help it. It could be something emission related, i've noticed that lights for emission stuff usually don't make much of a difference in the cars drivability. You need a OBDII scan tool for sure.

I disconected the battery to perform a ECM reset, but de Light is still on.

Found a repair shop who can read the OBD2, be going there tomorrow.

After that O Post the error Codes here, I hope its nothing big :-(


Greetings from Switzerland!!!

Just came back from the repair shop!

Error Code: P0401 EGR Flow Insufficient

So my fellow Monte Carlo Lovers what can I do now??

More then likely, considering the age of your Monte, it probably needs a new EGR valve. It's possible though that your EGR valve just needs cleaned though, so check that first.

When your car is declerating, the PCM tests your exhaust gas recirculation (EGR) by having it open and monitoring the manifold absolute pressure (MAP). When the EGR valve is opened, the PCM should see an increase in the MAP, if it doesn't if takes a note of how much of an increase didn't occur and when it stores enough to trip this light it will set it off.

Now you have to inspect the exhaust for leaks, remove the EGR valve and inspect the pintle, valve passages and the adapter for any deposits that could lead to a restriction. Also check the EGR valve gasket and the pipes for leaks.

If there is nothing there, you have to move on to the EGR inlet and outlet pipes from the exhaust manifold and the intake manifold. Inspect all the ports to make sure there isn't any blockage.

If there isn't a blockage in the system, it could be a poor connection at the PCM or EGR valve, take a look at the harness connectors for backed out terminals, improper mating, broken locks, poor connections. There could also be a vacuum restriction to the MAP sensor. Also just take a look at the whole harness to make sure there is no damage.

In order to clear the code, the system has to run 3 times and pass each consecutive time. Typically the test will only occur during gradual deceleration, and speeds above 25 mph.

First thank you all a lot for the help!!!

I removed the EGR and cleaned it, there where a lot of deposits there!

I also did a full cleaning after I found this nice tutorial:YouTube - GM P0401 EGR Troubleshooting by WELLS Engine Management

Since 3 days I didnt face any kind of trouble, so I guess the cleaning did its job!

Thanks guys