SES light came on, lw300

Got my first SES light this morning. After Jonnie Santos' problems, I wasn't
taking this one lightly.
2001, lw300
Engine was running fine and exhaust smelled clean. No drivability problems
but I read out the codes anyway. Don't have my own reader yet but the garage
next door to my office lent me theirs.

Only code logged was P0455 which showed EVAP leak (large)

I thought that the gas cap might have come loose but it was on tight.
Alldata shows a TSB related to this code. Anybody have any further info?

01-T-02A FEB 01 Emissions - MIL ON/DTC P0440/P0455 (EVAP) Set

I reset the code and light went off. Restarted the engine a few times and
light stayed off so far.
Am about halfway though the last tank of gas where I added a can of injector
cleaner. This is the first time I used the cleaner. On past cars, I had used
the cleaner every 6 months without problems.

Oppie

 

....insurance called today, and preliminary repair estimates are about $13k
which far exceed the value of the car (so they've totaled it). Next week
they'll make a settlement offer (they have to get another person involved in
the process). Other than being a little slow, so far I think they're trying
to do the right thing.

Glad my loss served some purpose if for nothing else as to add another layer
of caution in the diagnostic process.

Is an EVAP leak like when a gas cap isn't on tightly and or the cap seal has
failed?

 

_________________
|
| Is an EVAP leak like when a gas cap isn't on tightly and or the cap seal
has
| failed?

The P0455 code came back today.
Now I am incredibly pissed off!
Having been a mechanic for years and being fairly competent, I can't even
find the Evap canister. Having read most of the 5000 pages in the shop
manual, I found them to be written from the standpoint of the tech who is
armed with the factory service scan tool and concerned with little else.
There are huge sections which equate diagnostic trouble codes to electronic
faults (nice) but few diagrams to show where parts are located.

I found the evap canister purge solenoid on the right front fender well. It
is working OK. Can't find where the evap canister vent solenoid nor the
canister are located. I have a sinking feeling that it is on top of the fuel
tank and the tank has to be dropped to service it. There is a leak somewhere
in the evap system. Fuel cap seems OK

One would think that the manual would have some schematic diagram of the
fuel system hoses and components. I can not find a useable one anywhere!
This is my first service attempt on the car and I must say I am not
impressed.

There is a form in the back of the service manual for sending
recommendations to Saturn about improvements in the manual. I intend to fill
one out shortly. GRRRRR!

Later - Oppie

 

Try looking under "V" for "Vapor Canister". {

It might be in a fender or behind the gas tank. Ehh... I forget where it
is on a L series.

 

| Try looking under "V" for "Vapor Canister". {
|
| It might be in a fender or behind the gas tank. Ehh... I forget where it
| is on a L series.
|

Would have been much easier to find if I had the manual on disk that was
searchable. The index in the print manuals is nearly non-existent. Think
that I found the vent solenoid up near the fuel door. Found that by looking
through 200 pages of connector drawings and found one marked evap vent
solenoid. The drawing had a note about location being near fuel door. Still
no clear indication where the canister is. Just have to trace out the hoses
now.
Still love driving the car but if this is what they mean by "a new type of
car company" I am unimpressed with their service documentation.

Think that I will try removing the purge solenoid and feed the canister line
with 5 psi air and look for air leaks with soapy water. The vent solenoid is
normally open (venting) unless powered and I can check it's electrical
circuits.


Also saw what is needed to change the timing belt. YIKES!
Glad I have a welder and a machine shop to make all the special tools needed
for alignment before taking off the old belt.

Oppie

 

Evap canister is mounted on top of the gas tank "to make it tamper
resistant" according to the manual. <yeah, right> If service is needed on
this, you have to pull the intermediate exhaust pipe and drop the fuel tank.
No nice service doors from topside :-((

Evap canister vent solenoid is mounted behind the fuel door. I think that
the valve had picked up a bit of dirt and was sticking open. There is a foam
filter on its inlet but the housing was choked with dust. I have to question
the sensibility of putting a vent behind the wheel well. With the vent
circuit pinched off, the tank seems to hold pressure. Cleaned the filter and
blew out the valve with air. Reset the code and will see again if the code
gets set.

There is also a pressure sensor similar to a MAP sensor mounted on the fuel
tank. It is used in the evap diagnostics where the vent solenoid is
energized to close it and the purge solenoid is energized to open it. A
vacuum should be pulled in the tank and then the purge turns off to hold the
vacuum. The sensor measures the rate of decay of vacuum in the tank to
determine if all is ok or the magnitude of the leak.

I have started annotating all the drawings in the shop manual similar to the
way my Ford and Chrysler manuals were done. Much easier to follow that way.
This is my first GM vehicle since I owned a '54 Olds 88 back in '65.

Oppie