service engine soon light

allbrandauto wrote:
as a auto shop owner and a motorhome owner I always laugh win I see posts like this that the government is ripping you off with all the emission systems on cars but they don't complain when there cars are getting 30 mpg instead of 15

You are a young man sir.. I remember when folks were saying WOW 15 MPG. DOUBLE DIGITS, who'd a thunk it?

Service engine soon sounds like one of those pilot squawks - maintenance fixes jokes

Squawk - Something loose in cargo bay
Fix - Something tightened in cargo bay

kerrlakeroo wrote:
The same guru who thought a Primathene mist asthma inhaler would destroy the earth and had them outlawed.

I and my senator are quite familiar with this one......evil cfc's!!

Thats just one of the causes of the "engine warning light" coming on. It's the cheapest reason though so thats a good thing.

as a auto shop owner and a motorhome owner I always laugh win I see posts like this that the government is ripping you off with all the emission systems on cars but they don't complain when there cars are getting 30 mpg instead of 15

gafidler wrote:
I have a 2007 winnebago voyage on a workhorse chassis, Had the service engine soon light come on , my gas cap was not on properly , what BRAIN Surgeon decided to have a warning light come on for a loose gas cap.

The federal government. and what's more you have been told over and over and over that a loose/missing gas cap can cause that to happen."(TV ad for On-Star showed Kelly Rippa calling On-Star due to check engine light.. Ur, Mam, Did you just get gas?)

Suggestion.. NOTE this applies to Gasoline engines, do not know if the parts are there for Diesels.

I plugged an OBD-II to Blue Tooth device into the port on my RV. I have TORQUE on both my Tablet and smart phone.. I can quickly connect to the ECM (Engine Control Module) and it will tell me .. In this case.. a pair of code numbers and the text.. Evaporative Emissions Control Leak, Major Leak (Also minor leak)

Not the only possible cause.. but #1 on the hit parade is "Loose or missing gas cap" and if you check the book that's the first thing they tell you to check.

NOTE: Torque is a "Glass Dash" type application. Very nice.. I paid for it nice and I don't often do that.

The same guru who thought a Primathene mist asthma inhaler would destroy the earth and had them outlawed.

So now you know and it wasn't a brain surgeon at all. Seriously, I thought this was pretty much common knowledge, but guess not and it is important to be aware of.

It's part of the evaporative emission control system. As fuel is used from the tank air must enter or a vacuum would be created and flow would stop. The cap lets air in but it wont let fumes go out into the atmosphere. The computer sees that there is a leak in the system and cil comes on. Same as the newer gas can that you fill your generator with, they have a fancy cap so people dont lose or not reinstall the little push on cap. Pollution doesn't come from just the tailpipe.

They keep doing all sorts of things to find ways to minimize hydrocarbon release. Some small engines such as Stihl string trimmers have a mechanism in the control handle that wont let you shut off the ignition unless the throttle trigger is in the idle position. They dont want the engine spinning at a higher speed and slowing down with the ignition off spewing air fuel/hydrocarbons. The flaw in that design was that the cable and plastic parts were very touchy. If it wasn't routed and adjust very carefully it wouldn't engage and let you accelerate. I swore every time I worked on one and could only wonder how many people really hold the throttle open with the engine racing and want to shut the ignition off. Saving the world one weed eater at a time.

Actually, that loose or leaking gas cap screws up the vapor recovery functions of the emissions system, affecting a relatively fragile engine performance balance. It's not normally a major drivability issue, and it's a low cost fix even if the cap needs replacing.