John52 Posted October 13, 2023 Share Posted October 13, 2023 How? The replacement mirror did not have the external temperature sensor If the computer doesn't know the outside temperature it won't activate the DPF - increased emissions...engine management light on... ....£thousands spent fixing non-existent DPF fault Quote Link to comment Share on other sites More sharing options...
Steve928 Posted October 13, 2023 Share Posted October 13, 2023 (edited) Seen this posted everywhere and I'm tempted to think it's O'Reillys having a laugh and seeing if they can create an internet myth; I can't think of a reason why ambient temperature would be important to the DPF regen procedure when injection timing and post-injections can produce the required 600C in seconds irrespective of ambient and coolant temperatures. I'm tempted to disconnect my mirror and watch the result.. I've seen a regen take place with coolant temperature pinned on zero and ambient at -10 degrees so I can't see what the problem would be. Edited October 13, 2023 by Steve928 Quote Link to comment Share on other sites More sharing options...
Keithl Posted October 13, 2023 Share Posted October 13, 2023 No it is NOT an internet myth! Without the ambient temperature reading the ECM is unable to perform the regen and throws a code. The fact you have seen a regen happen at - 10 degrees is perfectly normal behaviour and does not mean the system will regen without a temperature reading. Quote Link to comment Share on other sites More sharing options...
John52 Posted October 13, 2023 Author Share Posted October 13, 2023 41 minutes ago, Steve928 said: I've seen a regen take place with coolant temperature pinned on zero and ambient at -10 degrees Yes but with no thermometer connected the computer won't know its -10 degrees These things have to be designed for worldwide operation so for all the computer knows the DPF could be much colder and too cold to burn off the soot. Quote Link to comment Share on other sites More sharing options...
Steve928 Posted October 13, 2023 Share Posted October 13, 2023 My point is that it doesn't need to (know the outside temperature). If it can generate 600C DPF temperature at will then why is the outside temperature of any interest? Quote Link to comment Share on other sites More sharing options...
Steve928 Posted October 13, 2023 Share Posted October 13, 2023 (edited) 17 minutes ago, Keithl said: Without the ambient temperature reading the ECM is unable to perform the regen Please give a precise and clear explanation of the logic that backs up your statement. Edited October 13, 2023 by Steve928 Quote Link to comment Share on other sites More sharing options...
John52 Posted October 13, 2023 Author Share Posted October 13, 2023 14 minutes ago, Steve928 said: My point is that it doesn't need to (know the outside temperature). If it can generate 600C DPF temperature at will then why is the outside temperature of any interest? I guess because it isn't going to be 600C by the time it penetrates the DPF if the van is speeding along at -40C or whatever? Quote Link to comment Share on other sites More sharing options...
Steve928 Posted October 13, 2023 Share Posted October 13, 2023 (edited) Varying post-injections quantities are used to regulate the DPF temperature to cicra 600C. In practice the ECM is always chasing the game by milliseconds and I've seen 580-670 in practice, but constantly varying. Given such near-instant power to generate heat in the DPF itself I still fail to see why minor (in comparison to internal DPF temperature, which the ECU knows) outside temperature variations are of any importance, especially when the DPF has c. 300-400 degree exhaust gases passing it through it anyway; it couldn't give a fud about the outside temperature. Edited October 13, 2023 by Steve928 Quote Link to comment Share on other sites More sharing options...
Keithl Posted October 13, 2023 Share Posted October 13, 2023 It is purely down to the way Fiat have programmed it! Without a plausible outside temperature reading the ECM prevents a regen and throws a fault code. I watched a video a few days ago showing exactly this fault and how simply replacing the temperature sensor in the RH door mirror fixed the problem. I'll try and find it and post a link. Now I've watched the video @John52 posted above it was the same video. Keith. Quote Link to comment Share on other sites More sharing options...
John52 Posted October 13, 2023 Author Share Posted October 13, 2023 2 minutes ago, Steve928 said: Varying post-injections quantities are used to regulate the DPF temperature to cicra 600C. In practice the ECM is always chasing the game by milliseconds and I've seen 580-670 in practice, but constantly varying. Given such near-instant power to generate heat in the DPF itself I still fail to see why minor (in comparison to internal DPF temperature, which the ECU knows) outside temperature variations are of any importance. Maybe if the ambient temperature is very hot the temperature around the DPF could do some damage? Quote Link to comment Share on other sites More sharing options...
MikeF Posted October 13, 2023 Share Posted October 13, 2023 31 minutes ago, Steve928 said: give a precise and clear explanation of the logic My guess is without the sensor, perhaps a 10K NTC, the electronics will default to a stupid value. In turn the software gets confused and does not complete the DPF burn cycle. Mike Quote Link to comment Share on other sites More sharing options...
John52 Posted October 13, 2023 Author Share Posted October 13, 2023 3 minutes ago, Keithl said: replacing the temperature sensor in the RH door mirror As I understand it, you can't get the sensors separately. You have to buy the OE mirror complete at Fiat prices. Unless you can cut out the bit of the old mirror with the sensor in and plug it in You can put the sensor inside the door - won't be an accurate ambient temperature but near enough to satisfy the computer. 1 Quote Link to comment Share on other sites More sharing options...
Steve928 Posted October 13, 2023 Share Posted October 13, 2023 (edited) 36 minutes ago, Keithl said: Now I've watched the video @John52 posted above it was the same video. Keith. So just the sole video then and everyone claiming it's true, it's true, exclamation mark.. 40 years an embedded systems programmer and I stil fail to see why anyone would use a variable of no consequence. The heat generated by the introduction of uncombusted hydrocarbons into the oxidation catalyst is so powerful that it beggars belief that a mere 70 degree max (?) variation in outside temperature could have any effect. I guess I'll have to disconnect the temperature sensor and try. Edited October 13, 2023 by Steve928 Quote Link to comment Share on other sites More sharing options...
Keithl Posted October 13, 2023 Share Posted October 13, 2023 6 minutes ago, Steve928 said: I guess I'll have to disconnect the temperature sensor and try. That was not the only video I saw but the best one. I don't know the logic of why the lack of sensor locks out the regen but the engineer in Italy lust have had a reason! And yes please do try and let us know conclusively. Quote Link to comment Share on other sites More sharing options...
onecal Posted October 13, 2023 Share Posted October 13, 2023 (edited) Hi Yes it does sound illogical, but I am afraid it does shut down a lot of programs within the ECU and Fiat are not the only ones I have found with this outside temp problem It usally defaults to a figure of 40oC on some on Volvo it just gives three dash's and prevents some programs from running. It's the way it's programed. I have replaced some with a different sensor (Fiat one) for about €27/€28 and it worked fine I think I also answered it back here Posted August 9 (edited) You will have to see what the soot levels are first !, if it is very high for safety it may not start a regen you need to have it cleaned manually. Then make sure after a regen (if then needed, hopefully not ) or cleaning to ensure an oil and filter change of the correct spec is carried out as the old oil now may not be the correct spec' and may be contaminated Just a question to both the OP and yourself What is the outside temp reading ? Is it working correctly? Regards Edited August 9 by onecal Regards Edited October 13, 2023 by onecal 1 Quote Link to comment Share on other sites More sharing options...
John52 Posted October 14, 2023 Author Share Posted October 14, 2023 (edited) 11 hours ago, Steve928 said: So just the sole video then and everyone claiming it's true, it's true, exclamation mark.. 40 years an embedded systems programmer and I stil fail to see why anyone would use a variable of no consequence. The heat generated by the introduction of uncombusted hydrocarbons into the oxidation catalyst is so powerful that it beggars belief that a mere 70 degree max (?) variation in outside temperature could have any effect. I guess I'll have to disconnect the temperature sensor and try. I'd disconnect the temperature sensor on mine and try were it not for the fact I have another problem that may complicate it Code P24AE Particulate Matter (soot) sensor bringing on the yellow emissions light. At first I thought it was due to my secondary batteries but disconnecting them makes no difference. Online search shows it as a common fault with 2020/2021 Ducatos due to a batch of bad soot sensors, and none in the UK due to "the worldwide shortage of silicone chips". Or Brexit as an ebay search shows they are available in the EU. PS: neighbour did a forced regen on his van and melted the tarmac - so maybe thats the reason the computer won't do it without knowing the ambient temp? Edited October 14, 2023 by John52 Quote Link to comment Share on other sites More sharing options...
John52 Posted October 14, 2023 Author Share Posted October 14, 2023 (edited) There are also videos on you tube of people doing a manual clean of the DPF One guy put himself in hospital using a gallon of Wynns DPF cleaner and breathing in the fumes But a test showed the stuff that works best is a strong solution of dishwasher tablets / powder Second best was coca-cola Edited October 14, 2023 by John52 Quote Link to comment Share on other sites More sharing options...
John52 Posted October 14, 2023 Author Share Posted October 14, 2023 1 hour ago, John52 said: PS: neighbour did a forced regen on his van and melted the tarmac - so maybe thats the reason the computer won't do it without knowing the ambient temp? Imagine an automatic DPF regen on a super hot day and something melting / catching fire .... worldwide recall...reputation damage.... However small the risk its not one they can afford to take is it? Quote Link to comment Share on other sites More sharing options...
MikeF Posted October 14, 2023 Share Posted October 14, 2023 14 hours ago, John52 said: you can't get the sensors separately. https://www.micksgarage.com/d/sensor-exterior-temperature/products/0d493509262 Quote Link to comment Share on other sites More sharing options...
John52 Posted October 14, 2023 Author Share Posted October 14, 2023 2 hours ago, MikeF said: https://www.micksgarage.com/d/sensor-exterior-temperature/products/0d493509262 When I click that link I get ' "We're Sorry This page may have moved or is no longer available. Please check the URL you entered and make sure it's correct. You could also try using the search box at the top of this page, or browse our top selection of products below. Alternatively, you could use our live chat service at the bottom of this page where you can talk directly to our customer service team who will be happy to help." Put my reg number in (2021 reg Ducato 140), clicked on temperature sensors, and it came up 'Sorry we don't have products available right now' The sensor on my van appears to be moulded in as part of the mirror surround. So, as far as I know, you can't get Ducato ambient temperature sensors separately. And all the aftermarket mirrors I have seen are for the earlier models with no temperature sensor. You might find a sensor from another vehicle that works though - I dunno? Quote Link to comment Share on other sites More sharing options...
Robinhood Posted October 14, 2023 Share Posted October 14, 2023 33 minutes ago, John52 said: The sensor on my van appears to be moulded in as part of the mirror surround. So, as far as I know, you can't get Ducato ambient temperature sensors separately. And all the aftermarket mirrors I have seen are for the earlier models with no temperature sensor. You might find a sensor from another vehicle that works though - I dunno? Having dismantled a damaged OE Driver's side mirror, mine had the temperature sensor simply clipped in place in the mirror body (above the little "blister". I've removed it and retained it as a spare. You certainly couldn't get OE temperature sensors separately, and that is probably still the case. On my previous 'van I had a sensor failure (reading 36-40C in the UK Autumn. The warranty repair included a complete new mirror. You can, however, source sensor replacements aftermarket pretty cheaply, e.g. https://www.ebay.co.uk/itm/314317390232 ...though you would need to splice into the existing wiring. (the sensor end looks just like my removed OE version) Aftermarket mirrors with temperature sensors are relatively easy to source, in all arm lengths. Yours are probably "short arm", so: https://tinyurl.com/ducatomirrorts 1 Quote Link to comment Share on other sites More sharing options...
John52 Posted October 14, 2023 Author Share Posted October 14, 2023 15 minutes ago, Robinhood said: Having dismantled a damaged OE Driver's side mirror, mine had the temperature sensor simply clipped in place in the mirror body (above the little "blister". I've removed it and retained it as a spare. You certainly couldn't get OE temperature sensors separately, and that is probably still the case. On my previous 'van I had a sensor failure (reading 36-40C in the UK Autumn. The warranty repair included a complete new mirror. You can, however, source sensor replacements aftermarket pretty cheaply, e.g. https://www.ebay.co.uk/itm/314317390232 ...though you would need to splice into the existing wiring. (the sensor end looks just like my removed OE version) Aftermarket mirrors with temperature sensors are relatively easy to source, in all arm lengths. Yours are probably "short arm", so: https://tinyurl.com/ducatomirrorts Thanks for the links Seems I am out of date as usual Quote Link to comment Share on other sites More sharing options...
John52 Posted October 14, 2023 Author Share Posted October 14, 2023 (edited) If anyone doesn't know how a DPF works this is a short video, (without the nonsense you often get on youtube) that explains it well Edited October 14, 2023 by John52 1 Quote Link to comment Share on other sites More sharing options...
MikeF Posted October 14, 2023 Share Posted October 14, 2023 (edited) 5 hours ago, John52 said: Sorry we don't have products available right now' Sorry I am in Ireland with poor Internet, try this link for a sensor, https://www.fruugo.ie/new-fiat-citroen-peugeot-van-outside-temperature-sensor-underneath-mirror/p-222735943-475160955?language=en&ac=croud&asc=pmax&gclid=EAIaIQobChMIq7jr0Pz1gQMVb4tQBh0M2gLYEAQYBiABEgI0TPD_BwE Or https://www.amazon.co.uk/Automotive-Rearview-Temperature-71753245-Compatible/dp/B0C6LZFP2V/ref=asc_df_B0C6LZFP2V/?tag=googshopuk-21&linkCode=df0&hvadid=658877062259&hvpos=&hvnetw=g&hvrand=12938039884794962962&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=20479&hvtargid=pla-2195200257329&psc=1&gclid=EAIaIQobChMIq7jr0Pz1gQMVb4tQBh0M2gLYEAQYAyABEgKdHvD_BwE Or https://www.auto-doc.ie/febi-bilstein/15255943 Or, https://www.ebay.ie/itm/133672388697 The replacement I fitted last year didn't exactly match the existing cable loom but was a simple matter to splice in the replacement. Mike Edited October 14, 2023 by MikeF Quote Link to comment Share on other sites More sharing options...
onecal Posted October 15, 2023 Share Posted October 15, 2023 Hi Replacements sensors are available from Fiat (not for the exact model) I have fitted many They work and let the ECU programs work fine , as per my previous post Quote Link to comment Share on other sites More sharing options...
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