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Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Glen Strachan on July 7, 2015, 9:38 pm

Year of Manufacture *: 2006
Engine Size and Code *: 1900

Hi everyone
I am having some issues with a Vauxhall Zafira 1.9 with the twin cam fiat engine
Can anyone explain how the single pipe dpf sensor calculates differential pressure ?
Does it look at exhaust backpressure vs atmospheric or does it take MAP or MAF into consideration ?

Re: DPF pressure sensor with one pipe

Posted by Chris Angus on July 8, 2015, 4:37 pm, in reply to "DPF pressure sensor with one pipe"

I wouldn't worry too much about it and over complicate your testing, they're basically the same thing , they are just pressure sensors, except the twin pipe setup gives a more accurate back pressure reading of the dpf as it offsets the pressure that may exist in the remaining exhaust system after the dpf. The single pipe setup is measuring the whole pressure of the full exhaust system.

What's the problem with the car?

Re: DPF pressure sensor with one pipe

Posted by Glen Strachan on July 9, 2015, 8:55 am, in reply to "Re: DPF pressure sensor with one pipe"

It came in with MIL on two fault codes
P242F - DPF pressure sensor malfunction
P2279 - Air induction component leaking.

This vehicle has been to many garages having multiple parts bolted on and the customer has lost track of what parts have actually been fitted.

My worry is that actual values show DPF differential pressure set at -2kpa with the engine off or idling.
At WOT it goes up to about 6kpa

I have carried out a pressure sensor relearn and I have removed it and tested with mityvac and it seems to work ok.

The 242F has cleared now and hasnt yet returned but I am still getting P2279 when throttling off on at high speed on a bypass

Re: DPF pressure sensor with one pipe

Posted by Chris Angus on July 9, 2015, 9:29 am, in reply to "Re: DPF pressure sensor with one pipe"

Dpf pressure is ok then. I would be looking in to the air leak first, pay close attention to the egr valve. Have you got a smoke tester?

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Lee Mackintosh on July 9, 2015, 11:28 am, in reply to "Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"
Lee Mackintosh

Not sure if it can cause an issue but as Chris says EGR valves can leak externally from the solenoid to egr housing gasket which will show up on a smoke test.

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Glen Strachan on July 9, 2015, 12:05 pm, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

I have smoke tested everything and no sign of a leak. I have also blanked off EGR and still get the the same fault together with an insufficient egr flow code, so I was looking to see if this could be a map / airmass inconsistency hence the original question about a single pipe DPF pressure sensor.
I was wondering if the differential pressure was calculated using either of these sensors.

It looks like I will be removing the manifold to see if the swirl flaps or intake is heavily coked up although I can see the electric actuator working ok and the connecting bar is in place and seems to be working.
The OBD mode 2 operating conditions gives
ECT 81C
Rail Pressure 59290 kpa
Intake Air temp 31C
Calculated Load value 0.0%
Intake manifold absol pressure 110kpa
Eng speed 2448
speed 78km/h

I was expecting to see a higher MAP reading on overrun

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Chris Angus on July 9, 2015, 1:58 pm, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

Where are you doing the smoke test from?
does the gauge and flow meter confirm the system is holding pressure?
What are the MAF readings at idle and full load?

Log Maf, rpm, IAT, and boost on the road at full load and post the results.

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by keith brown on July 10, 2015, 10:33 am, in reply to "Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"
Keith Brown

Glen, has this car had a cambelt?
if so was it set with the proper tool?
had an insignia with similar issue & cambelt had been tipxed!
half a tooth out causing low intake mass hense "intake air leak" code hth keith

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Glen Strachan on July 11, 2015, 8:14 am, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

Engine speed 799 rpm
Air-mass, nominal 39.8 kg/h
Air mass taken in 46.5 kg/h
Particulate filter saturation 64 %
Particulate filter differ. pressure -1 kPa
Voltage/exhaust gas differ. pressure 0.45 V
Km since last DPF regeneration 68 miles

at WOT in the workshop air mass rises to 350 ish although I have not yet tested this on the road.

I have smoke tested from the air intake and the smaller vac pipes etc, flow test shows good on smaller pipes but does show flow on intake pipes.

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Glen Strachan on July 11, 2015, 8:29 am, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

I have not had the belt covers off, but that is a good shout.
I am going to play a little more this morning. The plan initially was to remove the manifold to take a look, but had the customer on the phone to say hold fire because she is getting trading standards onto the selling dealer ( even though he bought it 14 months ago )
Regardless, I am reluctant to let this go without a fix so am going to carry out some more tests and post up some actual values.

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Glen Strachan on July 11, 2015, 9:33 am, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

OK, some numbers in ...

2nd gear heavy acceleration
Engine speed 3154 rpm
Air-mass, nominal 414.1 kg/h
Air mass taken in 430.7 kg/h
Atmospheric pressure 100 kPa
Boost pressure 228 kPa
Boost pressure, nominal 240 kPa
Particulate filter differ. pressure 15 kPa
Vehicle acceleration 3.13 m/s²

2nd gear throttle off on overrun
Engine speed 3025 rpm
Air-mass, nominal 213.4 kg/h
Air mass taken in 222.7 kg/h
Atmospheric pressure 100 kPa
Boost pressure 125 kPa
Boost pressure, nominal 120 kPa
Particulate filter differ. pressure 5 kPa
Vehicle acceleration -1.25 m/s²

Engine speed 3487 rpm
Calculated accelerator pedal pos. 100 %
Air-mass, nominal 451.7 kg/h
Air mass taken in 470.5 kg/h
Boost pressure 239 kPa
Boost pressure, nominal 248 kPa
Particulate filter differ. pressure 23 kPa
Vehicle speed 32 mph

Engine speed 4075 rpm
Calculated accelerator pedal pos. 0 %
Air-mass, nominal 245.9 kg/h
Air mass taken in 255.0 kg/h
Boost pressure 134 kPa
Boost pressure, nominal 144 kPa
Particulate filter differ. pressure 10 kPa

Engine speed 2482 rpm
Air-mass, nominal 109.5 kg/h
Air mass taken in 115.3 kg/h
Atmospheric pressure 100 kPa
Boost pressure 110 kPa
Boost pressure, nominal 112 kPa
Particulate filter differ. pressure 2 kPa
Vehicle acceleration -0.47 m/s²

These numbers were taken with the EGR still blanked off

It looks to me that it is seeing a higher than normal air mass sometimes up to 6%.
Not sure if already mentioned but this does have a non genuine dpf . Could this be down to a lack of backpressure

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Glen Strachan on July 11, 2015, 10:30 am, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

So, with a rag stuffed up the exhaust :D

Engine speed 3762 rpm
Calculated accelerator pedal pos. 100 %
Air-mass, nominal 412.1 kg/h
Air mass taken in 433.3 kg/h
Boost pressure 236 kPa
Boost pressure, nominal 248 kPa
Particulate filter differ. pressure 52 kPa

Engine speed 3765 rpm
Calculated accelerator pedal pos. 0 %
Air-mass, nominal 218.3 kg/h
Air mass taken in 227.9 kg/h
Boost pressure 125 kPa
Boost pressure, nominal 136 kPa
Particulate filter differ. pressure 18 kPa

So it would seem that as expected Airmass and boost pressure have dropped, the difference between nominal and actual airmass remains in the region of 5%

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Lee Mackintosh on July 11, 2015, 3:56 pm, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"
Lee Mackintosh

Isn't 23kPa approaching the high side towards a restiction.

I always thought 150 upwards wasthe beginning of an issue.

Re: DPF pressure sensor with one pipe

Posted by andrew pethig on July 11, 2015, 6:10 pm, in reply to "Re: DPF pressure sensor with one pipe"
Andrew Pethig

just a thought, have a look at the turbo , waste gate operation or variable geometry actuator , i don't know what the zafira has.

most are vacuum operated or pressure, and problems here will give boost type codes.

in a vairable geometry the actuator should have a smooth operation and feel loose, not tight or notchey also if the actuator is controlled by vacuum check that that works properly like wise if it works from pressure.

done a few just lately with boost codes, and waste gate operation have been the culprit

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Glen Strachan on July 23, 2015, 8:19 am, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

The customer has taken this away as she is going to small claims to try and get her money back ( even though she bought it over a year ago ) , so it is unresolved at present although I expect I will be seeing it back in a few weeks time.

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by John Hall on July 30, 2015, 6:49 pm, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

Have you checked the intake flaps for operation and are they actually intact as these can cause P2279 ?

Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #

Posted by Glen Strachan on July 31, 2015, 8:17 am, in reply to "Re: Vauxhall Zafira 1.9 2006 - DPF pressure sensor with one pipe #"

Thanks John, I am pretty sure this is an intake problem. Externally they appear to be working ok.
Customer has taken this away , but I'm sure it will be back soon ...

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