Can anyone tell me what would cause a DTC of “P0440 - Evaporative Emission Control System Malfunction” on my ’97 855 T-5? This does not sound like the Loose Gas Cap code. I have fixed 3 leaks in the fuel/EVAP system quite a while before getting this code (broken EVAP tube, rotted EVAP tube elbow near the rear suspension and a misaligned seal on the fuel tank to the fuel pump) so I don't think there are any leaks in the system. Would this be the code for an EVAP valve that is failing?

Thanks for any helpful advise.

Yeah the book says causes can be: Clogged canister, Clogged hoses, or Defective Evap Valve itself (either permanently open or shut). Says you may notice fuel vapor smells from the canister or a high idle. Here's their procedure for troubleshooting it....

Code P0440 (EVAP System)
1) Check for other codes. If Code P0444 is also present,
check that code first. If Code P0444 is not present, go to next step.
2) Start and run engine at idle. Remove vacuum hose between
EVAP valve and intake manifold. If vacuum is present in hose, go to
next step. If vacuum is not present in hose, check for obstruction.
Also check hose connection to intake manifold.
3) Start and run engine at idle. Connect hose between EVAP
valve and intake manifold to EVAP valve. Remove hose between EVAP
valve and canister from EVAP valve. If there is no vacuum in EVAP
valve when valve is not activated, go to next step. If there is
vacuum, retest using new EVAP valve.
4) Start and run engine at idle. Disconnect hose between EVAP
valve and canister at EVAP valve. Check if there is vacuum in EVAP
valve when valve is activated. If there is vacuum, go to next step. If
there is no vacuum, retest using new EVAP valve.
5) Start and run engine at idle. Connect vacuum hose between
EVAP valve and canister to EVAP valve. Remove vacuum hose between EVAP
valve and canister from canister. Check if there is vacuum in hose
when EVAP valve is activated. If there is vacuum, check if all
canister inlets and outlets are okay. Repair as necessary. If inlets
and outlets are okay, fault is intermittent. Go to next step. If no
vacuum is present, check for obstruction in hose between EVAP valve
and canister.
6) Check hose between EVAP valve and intake manifold, and
between EVAP valve and canister for an obstruction. Check canister
connections to ensure they are not clogged. Check EVAP valve for dirt
or deposits. Repair as necessary. If no faults can be found, test
system using new EVAP valve.

Hope this helps....... Mike

Thanks Mike,

I checked most of this by intuition but what book is that advise from? It sounds like the Bently Manual I wish they made! The EVAP valve works fine but there is a part in the vacuum hose between the EVAP valve and the intake manifold that looks like a check valve but which has free flow in both directions that I am going to replace. Since the turbo can supply positive pressure this may be causing a problem.

But please - what book is that and where can I get it???

Thanks.

I have the factory shop manuals and the Mitchell's CD versions. You can get a CD with the shop manual information off of Ebay for less than $30. Here's one: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2413410799&category=6762 Or you can go to the Volvo North America website and order the paperback version of all the manuals but it will cost you about $250. Mike