Cleaning your XC90 ETM (it’s actually the throttle plate) is part of your overall maintenance. If your XC90 is idling poorly or is “rough” at stop signs (or if it stalls at stop signs), checking your throttle plate cleanliness (and cleaning it if it’s dirty) can help.
During my diagnosis of a P0177 OBD code, It was suggested by a good friend, and Volvo dealership mechanic, that I clean my throttle plate. Dealerships and other mechanics charge and incredible amount of money for this service, which includes unplugging and removing the unit from the car and re-installing with a new ETM (Electronic Throttle Module) gasket. However, it’s entirely possible to do a decent job cleaning the plate with the ETM in-place.
Cleaning my throttle plate with the ETM in-place is exactly what I did. Cleaning didn’t cure my P0177 code, it did make my Volvo run far better.
All you have to do is remove the ETM pipe that connects to the charge air cooler. Note that there’s a rubber hose that connects to this pipe between the cooler and the ETM and if this hose has never been removed before, you’ll likely need a new clamp to replace it. The rubber hose on my 2.5T was a crimp clamp, so I had a new hose clamp ready to install when it came time to put everything back together.
Aside from cutting the crimp clamp (use a pair of side cutters) It’s as easy as loosening the hose clamps at either end of the pipe. Once their loose, simply move the pipe out of the way. I don’t think there’s any way to get the pipe out from under the hood, so just shift it so that you have access to the throttle – that’s all we’re looking for here.
Before you grab your bottle off throttle cleaner, slide under your XC90 with a flashlight and look up at the plate to see how dirty it is (or isn’t). Take a pic with your cell phone for reference. Now, from above your engine, spray a clean rag with throttle cleaner (I used CRC) and start cleaning the plate.It may take a little bit of twisting of the wrist and fingers to get up there, but once you get a feel for it, you’ll do fine.
It may take some work to get your hand under the throttle to clean it, but you can do a decent job. I was even able to get the throttle plate open and clean along the edge (this helps when the XC90 is idling and the plate is in the closed position as there is still airflow when the plate is closed and any residue that blocks it could impact your idle. I opened the throttle plate with a small dowel wrapped in a cloth to keep the plate open and clean alone the edges.
Clean. Check. Clean, Check. That’s how this procedure goes. Once you feel like you’re in a good place, give the neck of the ETM a good cleaning too in case there’s any caked on gunk. Clean both ends of the pipe as best you can while you’re at it. Then, replace the pipe, make sure the clamps are tight and do an ETM reset procedure.
PRO TIP: If there’s oily residue at the connection between the charge air cooler and the ETM pipe, don’t fret – from what I gather it’s normal on any 2004 Volvo XC90 2.5T engine (and some other years and models). It’s simply oily vapors from the PCV system being sent into the intake and condensing into a liquid (oil) as they cool. Oil sticks to the inside of the pipe and gravity pulls it to the lowest point – the charge air / ETM pipe connection. Clean this area well and keep an eye on it.