I have a 02 S40, 120K miles. Reading the following codes:

P0234 - Turbo charger overboost condition
P0301 - Cylinder 1 misfire
P0302 - Cylinder 2 misfire
P0303 - Cylinder 3 misfire
P0304 - Cylinder 4 misfire

We were able to fix / remove P0101 - Mass or Volume Air Flow circuit Range / performance problem by cleaning it.

The car seems to start ok, but when you let up off the throttle, it gets rough.

My daughter says she was sitting at a redlight, and got no response when trying to idle forward. She looked at the dash and "ALL" the lights were on.

She put it in park, restarted and made it home. we haven't really done much since then except I cleaned the air flow sensor yesterday.


Any help would be greatly appreciated.

Thanks.

 

Maybe the turbo control valve is causing the wastegate to close all the time? If the car was making boost at idle it could cause problems. Do you have a vacuum gauge? Look for 17-22 inches/Hg at idle. You could also disconnect the TCV and wire the wastegate open so it does not make any boost.

Almost every time I've seen the cylinder misfire error code it was a coil or spark plug wire gone bad. In your case with all four cylinders showing misfire all at once it's probably related to either the MAF or the overboost.

 

Thanks for the ideas, however, my Haynes manual doesn't detail how to get to the control valve / waste gate and / or hook up a gauge.

I assume TCV = Turbo Control Valve.


Thanks.

 

IPD calls it a Boost Control Solenoid on the S40.
(BCS) Boost Control Solenoid

 

Lanelle,

Could be. Haven't had a chance to really dig into the engine yet.

As i stated in an earlier post, my Haynes manual doesn't really go into detail about the Turbo Control Valve and the Wastegate and how to get to them and do any sort of maintenance.

I'm hoping that once I take the engine cover off, it will be self evident, but with my luck, no way.

Any instructions / links to other areas where there are more detailed instructions than my Haynes manual would be greatly appreciated.

Thanks in advance.

 

Unfortunately the European version of the Haynes Manual is it for books. I went so far as to buy and install VIDA on my home laptop just to have more reference material.

The turbo and associated linkages can be accessed after removing the heat shield over the exhaust manifold. Best when the engine is cold as I had to put my weight on the engine as I leaned over to see back there. A drop light with a 100 watt equivalent CFL bulb works great. It's bright and stays fairly cool so you can lay it on your engine without fear of melting stuff.

 

Finally got to the back of the engine. Not much there. Disconnected what I think is the wastegate control arm from it's control arm. Ran the engine. Not much difference.

When the wastegate control arm is attached to the valve, is that the open or closed position?

How much do I have to move it to make sure it's open all them time?

Thanks. -- more to follow - maybe even today.

 

So i finally installed a new MAF, cleared all the codes and went for a drive. Ran fine except when we slowed or tried to idle. Had to keep a little gas on at all times to keep it from stalling.

What next.

 

How did it act when starting? When mine took a long time to crank and wouldn't idle without giving it gas I replaced the Idle Air Control motor. This did not fix it. I then replaced the Fuel Pressure Regulator and it started and ran fine after that.

 

Started right up, a little rough at first but after that just fine. Problems seemed to start after the engine got really warm. Then the idle issues started.

 

Might be time for a new Idle Air Control motor. I've read a few threads where idle issues were fixed by a new one. Try cleaning the old one first.

 

Agree that all indications point to needing to change / clean the IACM. But once again, my haynes manual comes up short - it has NO instructions on how to do this. Plus it has two engine sections one for GDI engine and one for a non GDI engine. Still don't know how to tell which one I have.

so if anyone can give pretty decent instructions on how to do this, I would greatly appreciate it.

 

GDI means Gasoline Direct Injection, which i assume is the normal angine, not sure what years and versions the Haynes manual you have covers.
You can always find a parts supplier online with a picture of the part and find it on the car that way....i do that a lot, not having a Haynes manual

 

Found the IAC. And then I noticed that there was a broken vacuum hose that went from just under the IAC to the top of the air conditioner radiator. This hose has two different diameter ends, so I just can't buy a new length of hose and replace it.

Where can I find this hose?

 

I've not found it online yet, only from the dealer. It's not overly expensive though. Mine has also been replaced once. Seems to get very brittle and snap in two.

 

Try the local home depot. They sell hose by the foot...make sure the ID is exactly the same....you can also get bulk hose online from Grainger or McMaster

 

Hose has two different diameters. 3/4" and 1"

 

You only really need the Inside Diameter (ID). Not sure the local Home Depot will have hose that large diameter, but i found McMaster Carr online has hose for push on fittings with an ID of 3/4" for under $5 a foot but you have to buy 5' minimum

 

It's a weird hose with two different diameters. Plus the short length with two 45* bends makes a generic hose difficult to fit. You might piece something together but it really needs to be OEM.

 

Just looked at mine...Hudini's right, a non OEM hose would probably kink.