How to - Differential Pressure Sensor Replacement

[theseriojca]

Hello

My 2010 XC90 SE Lux has been sporadically showing the 'Engine System Service Required' and in the last week the car would go into Limp Mode at the worst possible moments - up a steep hill, for example.

Connected VIDA and got the following codes:

ECM - 2A20 - Particulate Trap - Signal too low
ECM - 2A50 - Pressure Sensor Particulate Trap - Faulty Signal
ECM - 2A70 - Pressure Sensor Particulate Trap - Faulty Signal
ECM - 2B30 - Particulate Trap - Faulty Signal

Searched the forums and google and came upon a second hand pressure sensor on eBay, for £20. Bought it just in case, although it could have been the two rubber hoses as well, according to other cases on the internet. Decided to have a look at it, and if the hoses were fine, to swap the sensor itself.

The rain finally stopped in Glasgow, or rather became tiny hailstones, so decided to give it a go.

Here's what VIDA says on replacing the sensor:





In short, it's remove top cover, remove cross bar, remove back cover, replace sensor, put everything back where it belongs.

For the long version and pictures, keep reading.

1. Remove top engine cover - pull up from the front and gently manoeuvre around various plugs and wires on the right.

2. Remove cross bar - 4 x 13mm bolts on the suspension towers + 1 bolt on the top engine mount. For the top engine mount, you will need 2 18mm tools - a wrench and a deep socket, for examples. I wasn't able to completely remove it, actually - a random wire was attached to it (see picture). What is that wire and why is it only connected at the top (is the piece of plastic broken off?)







The mystery part - long piece of plastic, attached to the cross bar, with the wire zip-tied to it (sorry for the poor quality). Any ideas? It's dangling loose.





3. Remove back engine cover - 4 x 10 mm nuts - DO NOT DROP - finish off by hand and make sure to capture them before they roll off.



4. Disconnect two connectors off the back cover - separate and gently pry off, held by two plastic 'screws'.




5. Wiggle the back cover off and you're now able to see the Pressure Sensor, on the passenger side of the back of the engine, same region as top engine mount.



6. Disconnect the sensor plug.



7. Unscrew 2 x T25 screws holding the sensor - DO NOT DROP - limited space for that, can't fit a full size screwdriver.




8. Now, the real pain in the a*** part. The sensor is obviously connected to the two rubber hose bits, and since it wasn't disturbed for 11 years, it was a pain to take off. After A LOT of gentle praying, rocking, twisting and pulling, the sensor was finally freed, but do take your time. The space is limited, you need to be at full stretch, so not easy all together.



New sensor on bottom.



9. Once out, sliding the new sensor back on was actually pretty easy, just make sure the hoses go all the way up to the actual sensor body.


10. The rest of the process is putting it all back together - the opposite of taking it apart.

11. Extra step - Resetting adaptation differential pressure sensor particle sensor.

For this, connect VIDA, but don't start the car yet. Turn the ignition on, click on the link in VIDA (at the bottom of the Pressure Sensor replacement unit), then click on VCT2000 image/button.

A screen will pop up, press Start then wait until you are told the process is finalised.






That's pretty much it, I haven't had a chance to drive the car yet, but after running the engine for 20 minutes, with a few restarts, no codes popped up at all, so fingers crossed!

If you've got any idea on what that dangling piece of plastic is, from step 2, please let me know!

Thanks, comments and criticism welcome.

[SwissXC90]

> The mystery part - long piece of plastic, attached to the cross bar, with the wire zip-tied to it (sorry for the poor quality). Any ideas? It's dangling loose.

This is a cable duct for the ABS sensor wire to the front right wheel.
On my car it was dangling far too close to the crankshaft pulley, I tied it back with another cable tie.

So just make sure on your car it has no chance of rubbing on any moving parts.

[Spikermundo]

HI

Could you point me in the correct location for the adaptation of differential pressure sensor particle sensor. Seem to have been all around Vida but cannot find that part.

Thanks

[theseriojca]

Originally Posted by Spikermundo

HI

Could you point me in the correct location for the adaptation of differential pressure sensor particle sensor. Seem to have been all around Vida but cannot find that part.

Thanks

Go to

Information >

Repair >

2 Engine with mountings and equipment >

25 Intake and exhaust >

254 catalytic converter and emission control >

Pressure sensor, diesel particulate filter, replacing

Hope that helps

[Spikermundo]

Hi

Thanks for the very quick reply just checked that and its where i found the how to remove and replace but no recalibrate so assume it does not need doing on my car 4164T V50. Other parts do ie EGR if replaced seen that in vehicle communication advanced. Thankyou once again

[theseriojca]

here's what it looks like when I scroll all the way to the bottom of the replacement instruction

[Spikermundo]

Ok thanks will take another look but sure it shows you how to take it out and put it back that's it no other page to the side or lower looks like a trip to Volvo if values don't increase

so far

New Dpf (reset in vida)
Eoyls Fluid filled 15/15 (reset and primed)
New pressure tubes
New fuel filter (engine started to cut out)
Replaced pressure sensor with genuine used but low values (new one on order)

still getting pressure sensor value of 1 on tick over

[Spikermundo]

Attachment of my screen with no other instruction guess im in the right place

[Spikermundo]

Ok think I have solved this I also have a 2013 V40 2.0d that I have hooked up to Vida and checked the repair for the sensor it has the adaptation instructions at the bottom of the screen so assume the 1.6 is just plug and play. Fingers crossed