Exhaust temp sensor wiring

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207Peugeot14
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Exhaust temp sensor wiring

Post by 207Peugeot14 »

Hi all i hope you are all keeping well,

I'm trying to check my wiring on my exhaust gas temperature sensor back to the ECU,

My chassie number is VF3**************[VIN obfuscated, can be read by forum staff]

I will be totally honest I'm just a diyer on cars and I can obviously see the cable colours at the exhaust gas temperature sensor but I've no idea how to read a wiring diagram to see/know what pin numbers they are at the ECU end.

Any help would be very much appreciated thanks
207Peugeot14
Donor 2021
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Re: Exhaust temp sensor wiring

Post by 207Peugeot14 »

I have located these wiring diagrams....

Am i right in saying they conect to pins B19 and B20

On the ecu?

Thanks for your help
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20220323_161424.jpg
20220323_161410.jpg
20220323_160843.jpg
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GiveMeABreak
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Re: Exhaust temp sensor wiring

Post by GiveMeABreak »

They do: (PS - I deleted your other post on this same subject as it asked the same question, to avoid duplication of answers).

Wire 1268A: exhaust gas temperature sensor downstream of the catalytic converter A: signal is Pin (1) on the Upstream Exhaust Gas High Temp Sensor (UEGHTS)
Wire 1433A: pre-catalyst downstream exhaust temperature sensor earth A: signal is Pin (2) on the (UEGHTS)

These go to the 53 Pin Brown connection plug on the engine ECU:
1268A = Pin (20) on ECU
1433A = Pin (19) on ECU
207 pins.JPG
207Peugeot14
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Re: Exhaust temp sensor wiring

Post by 207Peugeot14 »

Thanks Marc that's much appreciated i will take a look and report back

Thanks again
207Peugeot14
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Re: Exhaust temp sensor wiring

Post by 207Peugeot14 »

Well checked the wires back to the ECU plug and all ok, so not sure what to check now

Thanks all
207Peugeot14
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Re: Exhaust temp sensor wiring

Post by 207Peugeot14 »

Took some readings of the exhaust gas temperature sensor today on the bench

At shed temperature
At shed temperature
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With heat gun on it
With heat gun on it
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GiveMeABreak
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Re: Exhaust temp sensor wiring

Post by GiveMeABreak »

Ok, so just to rewind a bit, you never actually stated what the issue was, but just asked for the wiring info, which has helped you do your checks I see, but I'm not sure what the fault is to start with.

If you can provide some more information and some fault codes for the specific issue, maybe we can chip in.
207Peugeot14
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Re: Exhaust temp sensor wiring

Post by 207Peugeot14 »

GiveMeABreak wrote:
04 Apr 2022, 12:46
Ok, so just to rewind a bit, you never actually stated what the issue was, but just asked for the wiring info, which has helped you do your checks I see, but I'm not sure what the fault is to start with.

If you can provide some more information and some fault codes for the specific issue, maybe we can chip in.

Sorry Marc
The car is running absolutely fine and no fault codes or warning lights on the dash what so ever, and is doing regenerations every 220miles,

Previously my dpf was blocked and while i was trying to get information on that issue it was pointed out to me that my exhaust gas temperature sensor was reading 149°c constantly... with a live scan showing this, it's been suggested that my car may be chipped but as far as I'm aware its not as the dpf is all still in place as ive just recently removed it and cleaned it.

And since putting it back together the cars been fine, but live data still showing a constant 149°c

Many thanks Simon
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GiveMeABreak
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Re: Exhaust temp sensor wiring

Post by GiveMeABreak »

Ok Simon, this may help with the readings:

The gas temperature sensor upstream of the particle filter informs the engine ECU of the temperature of the exhaust gases.

The NTC (Negative Temperature Coefficient) resistance value "R" changes in relation to the change in the temperature "T":
  • When the temperature "T" increases, the resistance value "R" decreases
  • When the temperature "T" decreases, the resistance value "R" increases
207 gas temp A.JPG
These are the readings according to the coolant temperature. So not ideal to use a heat gun and outside of the system, but the resistance seems to be changing correctly from what I can see with a heat gun - which would correspond to 850 °C according to the chart, and then dropping back to 19 ish at ambient 10 °C.
Minimum value (°C)Temperature (°C)Maximum value (°C)Resistance R (In Kohms )
-50-40-30133,8
-20-10046,76
-1001034,49
10203019,86
4050609,748
901001103,770
1401501601,802
1902002101,001
2402502600,616
2903003100,412
3403503600,293
3904004100,218
4404504600,168
4905005100,134
5405505600,109
5906006100,090
6406506600,076
6907007100,065
7407507600,056
7908008100,049
8408508600,043
207Peugeot14
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Re: Exhaust temp sensor wiring

Post by 207Peugeot14 »

Thanks for that Marc,

Something is not 100% then as it reads 149°c constantly on my pp2000/diagbox even when it's doing a regeneration, and the same 149°c on my mates snap-on scanner thinking mine may be reading it wrong...

Thanks simon