Fiat Ducato P2081 fault code - Exhaust gas temperature sensor circuit intermittent

[Googlebot]

Hi all,

Had the engine light on three times now. Cleared itself every time, now managed to get the code with an OBD reader as above.

The first time it just came on, second and third time it was while we were on a bumpy road which makes me think it is a dodgy connector.

It is a 2.3 Ducato 130BHP on a Hymer Exsis.

I have found the sensor, I think, and the connector seems fine. It is behind the engine in the exhaust just down from the turbo. New sensor is £75, so do I just replace and hope, or could it be something else?

I am a confident home mechanic, this however is beyond me with all the fault code stuff.

Anyone got an idea?

 

[Carolyn and Kev]

For what its worth.....Have someone else just check it out. Just to give you a peace of mind. Your description does make you think of a loose connection or faulty connector.
Its £50 on average for a check....if it costs a new sensor then it would be worth it. At least they can diagnose the fault and offer a warranty
Hope you get it sorted though

Kev

 

[Googlebot]

Thanks Kev, I would normally but most of the garages I normally use have most of their staff furloughed and as the fault clears, I haven't seen the need yet.

It will be open of those annoying intermittent faults that I won't find till it permanently breaks in Southern France.....

 

[Speve]

Are you sure it’s not the DPF doing a clean up? they do that ever so often though never had a fault light just the puff light.

 

[Googlebot]

It’s definitely the engine management light.

The only fault code is this one.

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[Carolyn and Kev]

Intermittent states a fault either with the sensor or...the cabling to it.

I would guess its the sensor to be honest? Only because it clears when you shut it off and then restart. The sensor sees a circuit then reboots for want of a description. Once it sees a fault...it shuts down.

Professional check first let them sort it out

 

[XxAnthxX]

 

[Googlebot]

There appear to be more than two wires, does that make a difference?

 

[XxAnthxX]

There appear to be more than two wires, does that make a difference?

They normally only have two wires....are you sure it‘s not the lambda (02) sensor you’ve found?
They sometimes have three.....

 

[Googlebot]

No idea, it was only just downstream of the turbo so I presumed it was the EGT Sensor.

I couldn’t see another one.

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[XxAnthxX]

There will be at least one 02 sensor (could be two, but I haven’t checked)

Check this with your registration number, if you do need a temperature sensor tho.
Broken Link Removed

 

[Googlebot]

Thanks for the help, I will have to jack it up again and have a crawl under it again.

To be fair if it’s only £27 for a new sensor, I might go for that just to see.

 

[XxAnthxX]

Thanks for the help, I will have to jack it up again and have a crawl under it again.

To be fair if it’s only £27 for a new sensor, I might go for that just to see.

There could even be two exhaust temperature sensors.....One either side of the DPF.

 

[Googlebot]

Update so far.

Euro car parts were doing a deal so I could get a new sensor for £60. I removed the old one and fitted the new, test run all fine!

Put it back on OBD reader and it threw up another fault. This time saying there was a short between the lambda sensor heater and the signal wires. Thought part must be duff so changed it and same happened.

Put old sensor back in and code goes away so must be an issue with the new sensor being wired incorrectly.

After a while idling the original code came back telling me the voltage from the sensor was intermittent.

A genuine FIAT one is £100 online or £150 from the stealers. Then there is the diagnostics of £100 at least.

So, what do I do now?

 

[Googlebot]

I should have listened to those that said take it to a garage.

I got a sensor from Fiat, £117 after a bit of haggling. Fitted it and guess what, exactly the same fault as came up originally. Must be the wiring then thought I!

Checked all the wiring back to the ECU, those A class Hymers aren’t made for mechanics are they! Anyway, nothing wrong, or loose etc, no corrosion and no issues I can see.

Must be the ECU then? Had a look at the training manual for that model and it mentions that the Euro 5 model has two temperature sensors, one in front of the DPF and one behind.......

I just changed the lambda sensor just behind the manifold....

Oh well, at least I have a working spare now.

It’s going to see a real mechanic who is a Ducato specialist on Thursday. I daren‘t spend another £120 on the temperature sensor to find out I am wrong again.

Moral of the story is don’t be stupid like me and if you are going to change sensors, be sure the one you are changing is actually the one the computer tells you is broken!

Interestingly, I tested the temperature sensor and the resistance went up and up when connected to my multimeter which was odd, but being thick I have no idea if this means it’s broken.

I will update further on my tale of stupidity and amateur tinkering on Thursday after someone who actually knows how to fix them tells me what to change.

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[Neil Bedwin]

Someone will correct me if I am wrong but....

If the resistance reading goes up when you measure it it normally means you have a capacitor in the circuit as to read ohms the meter puts a voltage across the connection. This voltage charges the capacitor and the resistance goes up.

 

[Googlebot]

See, I knew someone could explain it.

So is it duff?

This is well outside my area of expertise!

 

[Neil Bedwin]

So is it duff?

Maybe..... Temperature sensors are usually variable resistors. The resistance varies with how hot they get so all the ECU has to do is read the resistance and it knows the temp. If the sensor was open circuit or short circuit then it is duff. Having a capacitor in there is a little unusual.

 

[Googlebot]

Thanks for the help.

I will wait for the mechanic to have a look before my wife kills me!

 

[Googlebot]

Hopefully the final post!

Mechanic suggested to test the circuit was good and if so, it was the sensor.

Circuit was good from sensor to ECU so ordered the sensor. £120!

Fitted tonight and no fault code or engine light. Fingers crossed it’s sorted.

Anyone need a lambda sensor?

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[Yorkshire Puds]

Hi all,

Had the engine light on three times now. Cleared itself every time, now managed to get the code with an OBD reader as above.

The first time it just came on, second and third time it was while we were on a bumpy road which makes me think it is a dodgy connector.

It is a 2.3 Ducato 130BHP on a Hymer Exsis.

I have found the sensor, I think, and the connector seems fine. It is behind the engine in the exhaust just down from the turbo. New sensor is £75, so do I just replace and hope, or could it be something else?

I am a confident home mechanic, this however is beyond me with all the fault code stuff.

Anyone got an idea?

May I ask which OBD reader you used? I want to buy one but the information on which ones work is sketchy at best.

 

[Googlebot]

Amazon product ASIN B07MHRDPJZ
It worked on mine, apparently it might not work on Fords though.

At a tenner, I was happy to take the chance.

I used it with this free app.

‎Car Scanner ELM OBD2

‎Check what your car is doing in realtime, get OBD fault codes, car performance, sensor data and more! Car Scanner is a vehicle / car performance / trip computer / diagnostics tool and scanner that uses an OBD II Wi-Fi or Bluetooth 4.0 (Bluetooth LE) adapter to connect to your OBD2 engine...

apps.apple.com

Happy to report the light is still off.