Exhaust Gas Temp Sensors (2015 mk8 2.2 Euro 5)

[micmacdevon]

Hi all

Can anybody give guidance on following please.

2015 mk8 2.2 rwd euro 5

Issues with dpf regeneration

Live data on a stone cold engine shows 63 degrees C on both sensor 1 (green) and 2 (blue)

I have tested with multimeter and there is no resistance (or continuity) on either when tested on its terminals.

Sensor 3 is showing 0.207 ohms on the 2k ohms setting of multimeter.

Ambient temp is approx 16C

Google AI says that these are NTC sensors and should show resistance.....but not sure this is the case ?

Should I assume that these sensors have been fried !? and need replacing ?

At £183 each from ford I want to be sure !!!!!

Many thanks.

[metalworker0]

why would it have three temperature sensors, i would have thought one was enough.
the others are maybe pre dpf and post dpf pressure sensors

and the temperature sensor ..i reckon it works same as K-type

no resistance - it makes voltage

from wiki

A Type K temperature sensor, also known as a thermocouple, works based on the Seebeck effect, which creates a voltage when two different metals are connected and exposed to a temperature difference. In a Type K thermocouple, the metals are Chromel (nickel-chromium alloy) and Alumel (nickel-aluminum alloy). When these metals are joined, and one junction is exposed to a temperature gradient (a temperature difference), a voltage is generated, proportional to the temperature difference. This voltage can be measured and correlated to the temperature using standard calibration tables or electronic devices.

all the best.mark

[micmacdevon]

Should add......

Live data shows both as having 4.995V on them.

Cheers

[micmacdevon]

why would it have three temperature sensors, i would have thought one was enough.
the others are maybe pre dpf and post dpf pressure sensors

and the temperature sensor ..i reckon it works same as K-type

no resistance - it makes voltage

from wiki

A Type K temperature sensor, also known as a thermocouple, works based on the Seebeck effect, which creates a voltage when two different metals are connected and exposed to a temperature difference. In a Type K thermocouple, the metals are Chromel (nickel-chromium alloy) and Alumel (nickel-aluminum alloy). When these metals are joined, and one junction is exposed to a temperature gradient (a temperature difference), a voltage is generated, proportional to the temperature difference. This voltage can be measured and correlated to the temperature using standard calibration tables or electronic devices.

all the best.mark

Hi Mark

This has 3 on from what I can see.....

All 3 show on diagnostics

Bank 11 is pre dpf
Bank 12 is mid dpf
Bank 13 is post dpf

Cheers

[micmacdevon]

why would it have three temperature sensors, i would have thought one was enough.
the others are maybe pre dpf and post dpf pressure sensors

and the temperature sensor ..i reckon it works same as K-type

no resistance - it makes voltage

from wiki

A Type K temperature sensor, also known as a thermocouple, works based on the Seebeck effect, which creates a voltage when two different metals are connected and exposed to a temperature difference. In a Type K thermocouple, the metals are Chromel (nickel-chromium alloy) and Alumel (nickel-aluminum alloy). When these metals are joined, and one junction is exposed to a temperature gradient (a temperature difference), a voltage is generated, proportional to the temperature difference. This voltage can be measured and correlated to the temperature using standard calibration tables or electronic devices.

all the best.mark

Hi Mark

This has 3 on from what I can see.....

All 3 show on diagnostics

Bank 11 is pre dpf
Bank 12 is mid dpf
Bank 13 is post dpf

Cheers

There is a separate mid dpf pressure sensor around the other side......

[metalworker0]

not owning a mk8 ...where is that device located ...if its right after the engine, its the catalyst not the dpf

all the best.mark

[micmacdevon]

not owning a mk8 ...where is that device located ...if its right after the engine, its the catalyst not the dpf

all the best.mark

[metalworker0]

think its maybe a combined catalyst and dpf - well on ford diagrams on cat-car its called a catalyst and particulate filter assembly

in ebay its just called a DPF

explains why so many sensors ..wouldn't like to replace it £££££££

Now wen have to work out if the sensors work like a K-type thermocouples..if so maybe barking up the wrong tree with Resistance measurements.

all the best.mark

[metalworker0]

found this post about such a exhaust gas temperature sensor

First check continuity between the two wires of the thermocouple. If you have continuity it's probably fine. Usually they are either good or bad, but in rare cases they can be compromised by corrosion or something. To check if it's accurate you'll need a voltage meter than can read millivolts. Put the leads on each wire of the thermocouple. At 32*F the voltage across them will be zero. As temp increases the voltage goes up. 70*F will be .843 and 1000*F will be 22.251. I'll attach one of the standard voltage/temp charts for type K.

chart

https://www.ford-trucks.com/forums/atta ... download=1

chart is mind boggling --- like a bus time table for the whole of a county....im sure a simplified one can be found

all the best.mark

[micmacdevon]

found this post about such a exhaust gas temperature sensor

First check continuity between the two wires of the thermocouple. If you have continuity it's probably fine. Usually they are either good or bad, but in rare cases they can be compromised by corrosion or something. To check if it's accurate you'll need a voltage meter than can read millivolts. Put the leads on each wire of the thermocouple. At 32*F the voltage across them will be zero. As temp increases the voltage goes up. 70*F will be .843 and 1000*F will be 22.251. I'll attach one of the standard voltage/temp charts for type K.

chart

https://www.ford-trucks.com/forums/atta ... download=1

chart is mind boggling --- like a bus time table for the whole of a county....im sure a simplified one can be found

all the best.mark

No continuity or resistance at all in the first two (1 & 2) sensors which makes me think they are fried/faulty. Will pop them out and do temp against voltage test .
Cheers !