Hello!

I'm glad that I have found you! I am new to this forum and I am trying to find a solution for my issue. As I wrote in the title, the car is a S-Max 2.0 diesel 163hp from 2014.

The issue appeared for the first time in September. One morning, Engine service now message appeared on the dashboard and the car didn't start nor did it crank. I used a basic tester to read the errors and the single error was P244D-Exhaust gas temperature too high, Bank 1 sensor 1. After a bit of research I ordered a Forscan compatible tester and I bought a Forscan subscription. By the time I managed to get into their possession, the error disappeared and the car started. It worked without any issues for a few weeks, after which the error and symptoms reappeared. I managed to clear the error with Forscan, I reset the sensor values, I reset the PCM and the car ran again without issues for another few weeks. The third time it reappeared, I lifted the car and saw that there are 3 sensors in the DPF area. I disconnected the first sensor (before DPF) and the car started without tester intervention. I concluded that the respective sensor is to blame and bought a new one, mounted it, reset the values and reset the PCM. Only that after a few more weeks the issue reappeared. This time I couldn't delete the error with Forscan, instead after I left it for a day, it started without me doing anything.

From that moment on, I tried to go into details. On Forscan, in real-time parameters, only 2 sensors appeared, which gave normal values (100-300 degrees Celsius in the first minutes after starting). The DPF showed a 65% clogging degree, distance since the last regeneration 220 km. I lifted the car again to try to figure out what was going on with the 3 sensors. I unplugged sensor 2 and the car started and the value of sensor 2 remained fixed at 100 degrees even after driving for a while, so I plugged it back in. When I unplugged sensor 3, the car did not start and the tester clearly said that it was sensor 3. I should mention that I also measured sensor no. 1 with a multimeter and exposed it to different temperatures and it seemed to be behaving normally. Considering all this history, I am currently at an impasse. My opinion is that the problem is somewhere between the sensor and the computer and it only appears sometimes, I don't think it's related to the DPF regeneration. Under the car everything seemed fine, I don't think it's about water getting in, a short circuit or cables hanging out somewhere.
The error always appeared at home in the parking lot, after longer stops (24-48 hours), but that's not necessarily the rule, because it happened on other occasions that the car would sit idle for 1-2 days and the error wouldn't appear.
If anyone has encountered the problem and can guide me, I would be grateful. Another aspect that I didn't mention is that if the car starts, the error doesn't stay stored.

Thank you in advance!

I may be off the mark and I'm focusing on the DPF system as the only thing I can see at the moment is that the DPF differential pressure of 1kPa needs to be looked at to see if it is changing correctly.

It seems low for the soot loading of closed loop 70% and Open Loop 82% but there is no engine speed so that may be rubbish?
My personal understanding is that at idle the value should be around 1 kPa and at 3000 rev/min, maximum about 6 kPa.
If it doesn't change appropriately then the sensor, wiring and pipework need checking for blockage, leaks etc etc. 
The temperatures above look fine for normal running but once the vaporiser pump and glowplug routine starts when the soot loading reaches 100% the temperatures should go up to 550-650 Deg C.
To start a regen, various conditions need to be met.
One VERY common issue is blockage of the vaporiser plug and this should be tested by applying pressure to the fuel inlet pip - it should not hold a pressure, also the glow plug can fail and there are fuses for the glowplug and pump (I think)

I know I've sort of ignored the temperature sensors but I'd be looking for a regen to start and see the temperatures but, of course, the output can be checked at the probes (I'm unsure if they are thermocouples just changing resistance as temperature changes which your testing appears to confirm?) and then ideally at the ECU (but you'll likely need a wiring diagram?

I wouldn't expect that error would stop the vehicle from starting or why disconnecting temperature sensors would allow it to start and I don't know what "sensor values" you have reset?
Any fault can disappear when ignition is turned off then on so always read codes when it is misbehaving?

11 hours ago, Shearers said:

I may be off the mark and I'm focusing on the DPF system as the only thing I can see at the moment is that the DPF differential pressure of 1kPa needs to be looked at to see if it is changing correctly.

It seems low for the soot loading of closed loop 70% and Open Loop 82% but there is no engine speed so that may be rubbish?
My personal understanding is that at idle the value should be around 1 kPa and at 3000 rev/min, maximum about 6 kPa.
If it doesn't change appropriately then the sensor, wiring and pipework need checking for blockage, leaks etc etc. 
The temperatures above look fine for normal running but once the vaporiser pump and glowplug routine starts when the soot loading reaches 100% the temperatures should go up to 550-650 Deg C.
To start a regen, various conditions need to be met.
One VERY common issue is blockage of the vaporiser plug and this should be tested by applying pressure to the fuel inlet pip - it should not hold a pressure, also the glow plug can fail and there are fuses for the glowplug and pump (I think)

I know I've sort of ignored the temperature sensors but I'd be looking for a regen to start and see the temperatures but, of course, the output can be checked at the probes (I'm unsure if they are thermocouples just changing resistance as temperature changes which your testing appears to confirm?) and then ideally at the ECU (but you'll likely need a wiring diagram?

I wouldn't expect that error would stop the vehicle from starting or why disconnecting temperature sensors would allow it to start and I don't know what "sensor values" you have reset?
Any fault can disappear when ignition is turned off then on so always read codes when it is misbehaving?

Thank you for your reply, Shearers.

Regarding the previous screenshot and the differential pressure of 1 KPa, the engine was at idle (about 800 rpm). I introduced in real time parameters engine RPM and checked the differential pressure at 3000 rpm and it was 5 KPa (see the screenshot). From the last screenshot took few days ago, DPF had a regeneration (22 km as you can see in the new screenshot) and the 244D error didn't reappeared, so it is confirming that the sensor is not detecting an over limit temperature during regeneration.

Should I try a forced regeneration with the tester to see the parameters during regeneration?

Regarding vaporiser I know that it was changed 2 years ago and also the error specific to vaporiser issues is 244C which is about temperature too low during regeneration, while my sensor is detecting a too high temperature.

About testing the sensors I found on youtube some videos, I measured them and indeed the resistance is changing when the temperature changes (

When I say that I have reset the sensor values, again I followed a checklist found on the internet and the Forscan. They say that when you change the temperature exhaust gas sensor you should reset with Forscan the values (because there are some values in the ECU which can be different from an old malfunctioning sensor to a new one) and after that to reset the PCM from the Forscan to be sure that everything is clear. https://www.gelautomotive.co.uk/ford-p244d-not-starting/ 

"Any fault can disappear when ignition is turned off then on so always read codes when it is misbehaving?" I'm not sure that I understand correctly this question, but I will explain again when the error appears and how it disappear

The error P244D is present -> the car is not starting. The car is not starting -> P244D is present.

The car is starting, then P244D is not anymore on the tester, even if I didn't reset the ECU errors. Only one time I could erase the error, reset values and PCM and the car started. The other 3 time the error disappeared without a direct intervention of the tester.

If you have any other ideas or unclear information, I will try to explain other way or to bring more information from the tester or my experience.

Sorry for my English errors, I am not a native.

Thank you again and I hope that this post will help someday other users to clarify some temperature sensors related issues.

 

What you are saying is that the P244D being present stops the car from starting.

The logic behind that appears to be that the car is forced to stop as the DPF temperature is over the limit so prevents further damage?

It appears you can reset the fault code but it returns?

Forced regenerations IMHO are to be avoided if at all possible as they can overheat and damage the DPF.

In any case, your readings of differential pressure look OK to me and it looks like one has recently taken place, based on your last screenshot and, importantly, it didn't cause the fault code indicating that the regen is taking place normally?

The issue seems to be that the fault comes back so, to me, the exact time that happens and the reason for it may be the key to solving it?

I can't recall which of the two sensors  you said causes the code (front likely to be hottest due to vaporiser plug injecting fuel?) but the one causing the code is the system to focus on i.e. sensor itself, wiring at the sensor, all the way back through the wiring to the ECU looking for shorts across the sensor wiring, high resistance and shorts to earth, checking and load testing individual conductors.

If it's a thermocouple then as the temperature goes up, the resistance comes down. You may need to watch the temperatures on live data until the fault comes on at random when there is no regen occurring which would definitely (?) indicate a wiring fault and this is what you imply if the code goes away without any reset?

More and more, it's looking to me like an intermittent short across the sensor wiring somewhere and whilst I'm reluctant to blame the new sensor, it has been known?

The link you quote above seems to be "sensible":
https://www.gelautomotive.co.uk/ford-p244d-not-starting/
It does mention an ECU reset but I'm not sure what that means (either Forscan - or perhaps disconnect battery, being aware of radio codes etc to allow ECU to start from scratch - unsure how effective that would be - you appear to already have achieved that)
I'm also very very reluctant to blame the ECU and if it comes to that, it may be possible to get a repair. 
Again, that's my best.

 

did you end up fixing this and finding the error, or finding the cause

 

i have a 2018 smax ecoblue where i am having similar issues with exhaust temputures sensors giving  fixed 100 degrees on 2/3  and max out values on 3/4