[jonesb371]

Hey all,

I believe our UK 2007 1.6 CRDi i30 has a faulty DPF differential pressure sensor. The problem is that a replacement is dealer only, very expensive, and rare in terms of finding at an auto recyclers.

The part number is 392102A750. In the 2009> model of the same car the sensor was replaced with part number 392102A800. Does anyone know if I can use the newer version instead? The harness connector is the same and the inlets are the same too, but the newer version is less than 10% of the price of the matching version.

The current part is shown here http://hyundai.epc-data.com/i30/38447/engine/electronic_control-28390C11/sensor_diff_pressure-39210U/

The newer part is shown here http://hyundai.epc-data.com/i30/37445/engine/exhaust_pipe-28286C11/sensor_diff_pressure-39210U/

Thanks in advance!

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[tw2005]

I can't answer your question, the dealer should know if the new part is backwards compatible.

Don't understand the 10% bit but if you ordered from Koraps in Korea

392102A750 $86.30 USD + Freight + duty  etc
392102A800 $63.40 USD + Freighty + duty etc

It does say

After replacing the Differential Pressure Sensor (DPS), MUST perform the "COMPONENT CHANGE ROUTINE" procedure. Otherwise trouble related with engine performance or emission control may occur until ECM learning about the component is over.

also says may , until relearning but surely there's mechanics with equipment that can do the same as the dealer reset?

I cant find the first sensor via ebay though the second one if compatible is cheaper here For Hyundai Tucson Getz i30 Santa fe i20 Diesel Differential pressure sensor | eBay

[jonesb371]

Thanks both. The price difference came from the UK main dealer price I've been given of £300 for the older part, the newer part I've seen plenty of for around £25 on eBay and the like.

I've asked a couple of dealers if they can confirm but I doubt I'll get a straight answer from them really. One parts trader did say the two parts don't show as "linked" on their system which would suggest to them that they're not compatible, but that's all the info I've been able to get so far. Some breaker yards from abroad (Netherlands) have the newer part listed as being removed from vehicles with the same engine code D4FB if that means anything?

If I were to change it and the relearning process caused a real problem I could find a garage to set the component change flag I'm sure. At the minute the DTC being logged is P0472 Exhaust Pressure Sensor Low Input, so the current sensor probably isn't saying much of any sense to the ECU either.

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[tw2005]

Thanks both. The price difference came from the UK main dealer price I've been given of £300 for the older part, the newer part I've seen plenty of for around £25 on eBay and the like.

I've asked a couple of dealers if they can confirm but I doubt I'll get a straight answer from them really. One parts trader did say the two parts don't show as "linked" on their system which would suggest to them that they're not compatible, but that's all the info I've been able to get so far. Some breaker yards from abroad (Netherlands) have the newer part listed as being removed from vehicles with the same engine code D4FB if that means anything?

If I were to change it and the relearning process caused a real problem I could find a garage to set the component change flag I'm sure. At the minute the DTC being logged is P0472 Exhaust Pressure Sensor Low Input, so the current sensor probably isn't saying much of any sense to the ECU either.

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Unfortunately with something like this the dealer catalog would say if it is an update across the range. Sometimes you see this but in this instance there is no way of knowing whether the number change is due to specs or even just a different brand component.

Engine code alone is not going to help either as there could be several variants and there are because there are DPF and Non DPF.  A later model ECU could be calibrated to the newer model sensor.

It may actually produce the same output voltage and will work. Only Hyundai may know this and if a part has been interchanged then I'd expect the original to be superceeded and phased out of availability.

anyway, Koraps maybe a good option if you need the original then. 300 pounds leaves a fair margin to play with.

[jonesb371]

Unfortunately with something like this the dealer catalog would say if it is an update across the range. Sometimes you see this but in this instance there is no way of knowing whether the number change is due to specs or even just a different brand component.

Engine code alone is not going to help either as there could be several variants and there are because there are DPF and Non DPF.  A later model ECU could be calibrated to the newer model sensor.

It may actually produce the same output voltage and will work. Only Hyundai may know this and if a part has been interchanged then I'd expect the original to be superceeded and phased out of availability.

anyway, Koraps maybe a good option if you need the original then. 300 pounds leaves a fair margin to play with.

Yeah Koraps is a much less gut-wrenching price, so thanks for putting me in their direction I think a few more tests on the wiring harness just to be sure and then I'll get one ordered if I don't find any other issues that could be causing it.

[tw2005]

Unfortunately with something like this the dealer catalog would say if it is an update across the range. Sometimes you see this but in this instance there is no way of knowing whether the number change is due to specs or even just a different brand component.

Engine code alone is not going to help either as there could be several variants and there are because there are DPF and Non DPF.  A later model ECU could be calibrated to the newer model sensor.

It may actually produce the same output voltage and will work. Only Hyundai may know this and if a part has been interchanged then I'd expect the original to be superceeded and phased out of availability.

anyway, Koraps maybe a good option if you need the original then. 300 pounds leaves a fair margin to play with.

Yeah Koraps is a much less gut-wrenching price, so thanks for putting me in their direction I think a few more tests on the wiring harness just to be sure and then I'll get one ordered if I don't find any other issues that could be causing it.

just do your research on import tariffs etc. Over here we do ok , nil taxes or tariffs under $1000AUD but I was looking at the UK and VAT and duties seem to apply at lower thresholds. You'd be the expert on that one.

[jonesb371]

just do your research on import tariffs etc. Over here we do ok , nil taxes or tariffs under $1000AUD but I was looking at the UK and VAT and duties seem to apply at lower thresholds. You'd be the expert on that one.

Yeah VAT at 20% would certainly apply, that goes on anything over around £16 I think - we certainly get a rougher deal than you!

Looking again at diagrams I'm pretty sure no dealer catalogue is ever going to say the parts are compatible, because they fit on to totally different brackets and in different parts of the engine bay.

It wouldn't be so bad if I had a known good sensor to measure against, that way if I bought the newer part I could compare signal voltages and see if they were the same,and just return it if they were way off. But since I think the only one I have is busted I have no correct point of reference to start from.

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[tw2005]

just do your research on import tariffs etc. Over here we do ok , nil taxes or tariffs under $1000AUD but I was looking at the UK and VAT and duties seem to apply at lower thresholds. You'd be the expert on that one.

Yeah VAT at 20% would certainly apply, that goes on anything over around £16 I think - we certainly get a rougher deal than you!

Looking again at diagrams I'm pretty sure no dealer catalogue is ever going to say the parts are compatible, because they fit on to totally different brackets and in different parts of the engine bay.

It wouldn't be so bad if I had a known good sensor to measure against, that way if I bought the newer part I could compare signal voltages and see if they were the same,and just return it if they were way off. But since I think the only one I have is busted I have no correct point of reference to start from.

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the manual does give the outputs for given pressure differentials and the change is linear. So for nil difference between the 2 ports 1Volt for every 10 Kpa difference it increases by 0.35V. At 100kpa it will be 4.5v

they give a graph at idle with a new CPF the output is around 1-1.2V

[cruiserfied]

Why exactly are you jumping to sensor fault?
The DPS is a pretty simple sensor and fairly reliable. I assume you understand its workings and purpose.

Have you tried running with the hoses removed and seeing if DTC returns or changes?

[jonesb371]

Why exactly are you jumping to sensor fault?
The DPS is a pretty simple sensor and fairly reliable. I assume you understand its workings and purpose.

Have you tried running with the hoses removed and seeing if DTC returns or changes?

The fault code coming back with everything connected is P0472 - which from what I can gather is saying that the sensor voltage is saying that the atmospheric pressure reading at ignition on is lower than other sensors are reporting. I've not tested the signal return voltage while the sensor is connected yet, that's my next job when I get an hour or so to tackle it again

I've not run it with the hoses disconnected, but have done with the wiring harness disconnected, which gives DTC P0473, and also with a jumper between the signal circuit and ground circuit in the harness connector, which gives DTC P0472. A diagnostic guide I was following said that if the wiring continuity is OK, and P0472 is logged with the jumper connected between those pins, then the sensor is likely at fault. Voltages at the harness for the 5V supply and signal circuit are OK too.

There is also a P2002 code being logged, but a mechanic with a better scan tool than I own said that the soot loading is nowhere near high enough to be a full DPF, and it could be erroneous readings coming back from the sensor.

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[tw2005]

Been looking a little closer at this thanks to SUNDIZ.

I think I'd stick to the correct unit if you go to replace. Looking at your links and after 2009 theory, one of those is fitted to U, the other is fitted to U2.

Also that's a Japanese market catalog too I believe so dates in that may not be accurate for your region and or fitment.

Looking into the European region, again I'm seeing U has 750, U2 has 800 not worth the risk of inducing other issues using the wrong one I feel to save some money

[jonesb371]

Been looking a little closer at this thanks to SUNDIZ.

I think I'd stick to the correct unit if you go to replace. Looking at your links and after 2009 theory, one of those is fitted to U, the other is fitted to U2.

Also that's a Japanese market catalog too I believe so dates in that may not be accurate for your region and or fitment.

Looking into the European region, again I'm seeing U has 750, U2 has 800 not worth the risk of inducing other issues using the wrong one I feel to save some money

Thanks - I'm inclined to agree now you've pointed me towards one at a much more reasonable price on Koraps. If I can definitively prove the sensor is faulty then we'll get one ordered. I just want to fully rule out problems like wiring, split hoses or exhaust leakage first.

As an aside, the car does still drive absolutely fine and is being used for long motorway commutes at the minute. Hopefully it will survive a 3-4 week wait for the part to arrive from Korea...!

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[tw2005]

Been looking a little closer at this thanks to SUNDIZ.

I think I'd stick to the correct unit if you go to replace. Looking at your links and after 2009 theory, one of those is fitted to U, the other is fitted to U2.

Also that's a Japanese market catalog too I believe so dates in that may not be accurate for your region and or fitment.

Looking into the European region, again I'm seeing U has 750, U2 has 800 not worth the risk of inducing other issues using the wrong one I feel to save some money

Thanks - I'm inclined to agree now you've pointed me towards one at a much more reasonable price on Koraps. If I can definitively prove the sensor is faulty then we'll get one ordered. I just want to fully rule out problems like wiring, split hoses or exhaust leakage first.

As an aside, the car does still drive absolutely fine and is being used for long motorway commutes at the minute. Hopefully it will survive a 3-4 week wait for the part to arrive from Korea...!

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sorry, can't comment further, @cruiserfied is the techpert

[jonesb371]

sorry, can't comment further, @cruiserfied is the techpert

No worries - and thanks for all your help!


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[jonesb371]

Spent some more time with a multimeter today... Checked wiring continuity to the harness plugged in to the ECU for all three pins and they're all fine. The central pin of the harness that plugs in to the sensor reads 5.68V when disconnected, and when back probed and connected to the sensor it reads 1.01V and doesn't fluctuate at all. Even if I remove the exhaust hoses it stays at exactly the same value. So "P0472 exhaust pressure sensor low" is referring to that voltage being implausibly low I assume?

If 1V is a completely clean DPF (unlikely on a car that's done 115,000+ miles!) then I assume we can say with a fair degree of certainty that the sensor is faulty? Or the exhaust hoses/pipework is full of holes, but even then I'd have thought there'd be a slight change?

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[The Gonz]

I think I just read a thread where a DPF regen fault was cleared by replacing the sensors

[tw2005]

What's the resolution of the meter? An oscilloscope would be handy as it may be fluctuating but unseen on a standard mutlimeter.

[tw2005]

P0472 is set when the voltage below 0.85V - mimimum output voltage of DPS - is detected for more than 0.6 sec.. This code is due to open in power circuit or short to ground in signal circuit.

[tw2005]

I think a scan tool which can display the live data from the sensors would be a good way to go. I don't think a simple multimeter will do much other than show that supply voltage is present and an output which you also found. It says it's meant to hover around that figure anyway.

[Asterix]

I think I just read a thread where a DPF regen fault was cleared by replacing the sensors

Yep

DPF burn initiation

[tw2005]

 4.8V~5.1V is normal, allowing for some meter inaccuracy I'd say what you read is not an issue

[jonesb371]

I'm back :-)

I've done some more playing with a more accurate multimeter and the values do change by ~0.006V when the hoses are disconnected so the sensor is reading change correctly, which is a start!

What I did find was that when I applied pressure to the harness in a certain direction, the voltage would drop to ~0.232, and stay there until I reseated/rewiggled it back. Again this was measured by back probing at the sensor end not the ECU end, ruling out wiring issues, continuity from the crimped connectors in the harness back to the ECU checked again to be 100% sure though, and I wiggled the wiring trying to find a break but couldn't.

So, are there any ideas what I could do to diagnose next? Could it be some kind of issue internally in the sensor that causes the voltage to drop in that manner when pressure is applied - or maybe a problem with the crimped connections on the +5V supply or GND that causes that connection to break when pressure/movement goes in a certain direction, and that makes the output voltage drop?

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