DPF differential sensor pressure - 1000hPa

[qwadron]

I have 3 errors related to DPF Differential Pressure Sensor. Among them is:
- P2454 - DPF Differential Pressure sensor Circuit Low

Symptoms: No power over 3000rpm, Check Engine light ON, and no Cruise Control feature.
I can drive a car but is in "a safe mode".

I have connected the car to the diagnostic computer - Volvo Vida.

When the DPF Differential Pressure Sensor is connected is reads around 1000hPa value. There is slightly decrease in reading when I accelerate (down to 900hPa). It seems that the pressure is very high. I have to mention that I have new DPF filter (only 500km mielage).

When I disconnect the connector from DPF sensor the values remains the same. Nothing is changed. I conclude that when DPF sensor is diconnected there should be a value of 0hPa.

In my opinion there is some problem with electronics on the way between ENGINE MANAGEMENT computer (DPF has dedicated PINS in mentioned computer) and DPF sensor (either cables, connectors or the computer itself). Fuses are good.

I have cleared the errors but it was not helpfull.

[camturbo]

In mine the pins on the sensor were opening up when it was hot causing high dpf readings,the garage put some new ones in and it solved the issue I had,might be of some help. Also I believe the cruise control has something to do with the brake light switch on the pedal I think. Sorry I can't be of any more help. Hopefully someone else will be able to answer with more knowledge than me.

[7050man]

What year car do you have and what is the model?. My V50/S40 Early Euro 4 2.0ltr model had a problem with condensation in DPF that would cause erratic readings. Mine had two failures in my ownership. First at 40k miles, second at about 100k miles.
Sensor was changed, car driven for 20 miles or so under different conditions and fault gone.
Symptom when failing was limited revs (approx 2800) and would invariably clear when engine stopped and restarted.
First one replaced under warrenty, second one sourced from a Ford dealer (exactly the same part).

[Oldbrook]

The pins on my DPF sensor were corroded due to moisture. Volvo replaced the connecter and been ok since. £5 for plug and £120 for labour to find the problem, take it apart and have a good look at it mate, Dave

[qwadron]

Originally Posted by 7050man

What year car do you have and what is the model?. My V50/S40 Early Euro 4 2.0ltr model had a problem with condensation in DPF that would cause erratic readings. Mine had two failures in my ownership. First at 40k miles, second at about 100k miles.
Sensor was changed, car driven for 20 miles or so under different conditions and fault gone.
Symptom when failing was limited revs (approx 2800) and would invariably clear when engine stopped and restarted.
First one replaced under warrenty, second one sourced from a Ford dealer (exactly the same part).

Thanks for your suggestions.
My car: Volvo C30 2.0D 100kW 2007 year (2008 according to Volvo Vida).

1I am going to get into EMC (engine management computer) disconnect 3 PINS that are dedicated to DPF sensor and check resistance of the cables.

I am also thinking that the problem might be with the connector (next to the DPF sensor) and I will start with it.
Gladly there are great technical resources for my model.

[qwadron]

Originally Posted by Oldbrook

The pins on my DPF sensor were corroded due to moisture. Volvo replaced the connecter and been ok since. £5 for plug and £120 for labour to find the problem, take it apart and have a good look at it mate, Dave

Do you know what is the part number of the connector?
It is the same as this:
http://photobucket.com/gallery/user/...MDU1OQ==/?ref=

[Clan]

Originally Posted by qwadron

I have 3 errors related to DPF Differential Pressure Sensor. Among them is:
- P2454 - DPF Differential Pressure sensor Circuit Low

Symptoms: No power over 3000rpm, Check Engine light ON, and no Cruise Control feature.
I can drive a car but is in "a safe mode".

I have connected the car to the diagnostic computer - Volvo Vida.

When the DPF Differential Pressure Sensor is connected is reads around 1000hPa value. There is slightly decrease in reading when I accelerate (down to 900hPa). It seems that the pressure is very high. I have to mention that I have new DPF filter (only 500km mielage).

When I disconnect the connector from DPF sensor the values remains the same. Nothing is changed. I conclude that when DPF sensor is diconnected there should be a value of 0hPa.

In my opinion there is some problem with electronics on the way between ENGINE MANAGEMENT computer (DPF has dedicated PINS in mentioned computer) and DPF sensor (either cables, connectors or the computer itself). Fuses are good.

I have cleared the errors but it was not helpfull.

right what is the sensor reading with the engine off and ignition on ? It should be around zero of course , and fairly low when idling about 3 to 20 hpa depending how much soot .. a good rev should send it above 50 hpa ...

no idea what the reading is with the sensor disconnected ! but it seems one of the three wires going to the plug may be broken ! when you were driving the pressure went down ? Are you sure the pipes are on the right way around ? There is a small pipe and a larger pipe on the sensor and Actual particle filter ..

[KBB]

DPF issues are quite simple to diagnose. First test is to confirm that the DPF is not clogged. Easy test is to use a typical combination vacuum and pressure gauge that reads 10psi or less. Disconnect the DPF sensor from the pipe work and connect the gauge to the pipe leading up stream on the engine side of the DPF. Test for pressure at idle, part load and a good full rev test. A decent flowing DPF should be below 3psi of back pressure.

The sensor and circuit electrically are a fairly simple arrangement. 3 wires form the circuit namely a 5v reference voltage, a ground back to the ECU and a variable signal voltage. Do not waste time with conducting any resistance tests, they are time consuming and at best locate an open circuit. Any ohms readings are not to be trusted as this is an open circuit test with an unloaded electrical circuit. Dynamic testing is the only conclusive tests to conduct.

Leave the sensor connected ignition on and engine off and back probe the 3 wires, locate the 5v reference, signal wire and the ground. The ground should be low in the region of 0.1-0.2v steady if the reading on the meter will not stabilise and is high suspect the ground has high resistance, this fault will cause a false elevated reading on the signal voltage. a good test for the ground is to use the old but trusted automotive test light with the fly lead and crock clip, they dram no more than 250ma and the sensor typically run at around 150ma. connect the test light to bat pos and the tip to the ground cable, if it lights up bright then the ground from connector to the ECM and ECM to ground are good.

You can run a by pass test on the signal wire with the same test light tool. With scan tool in live data connect test light to bat pos and tip to signal wire, live data reading should rise, next connect test light to ground and tip to signal wire this will pull any bias voltage to ground and live data should show a low reading, this will confirm the signal wire is good back to ECM.

The 5v reference can be tested with a multimeter and the test light. Connect test light to ground, connect multimeter at the connector on the 5v reference pin and a good chassis ground, meter should read 5v, then with the test light touch the multimeter pin whilst on the 5v reference pin, the 5v should remain stable, if it drops with the load of the test light there is a high resistance fault on the 5v supply cable.

In my own experience, if the signal voltage output remains high thn either the ground to and through the ECU is faulted or the ground through (internal to) the sensor is open circuit.

Typical signal senor voltages are:
Key on engine off 0.5v plausibility voltage.
Idle 1-2v
Full acceleration 1-2v
Readings getting above 2v are now detecting soot accumulation.

The actual conditions and various sensor input values for passive regeneration to begin are for another day, but needless to say there are many faults or incorrect input signals that will prevent passive regeneration from taking place.