Just had my first case of "restricted performance" just as I got home from a short journey....

Plugged in IID and comes up with error code "P040D-00 (2F) Exhaust gas recirculation temperature sensor A - circuit high"

Cleared fault but comes back when engine started. Checked live values and EGR position on bank 2 says 0% when position requested by ECU is 16%. EGR on bank 1 shows around 40% requested and 40% actual position so appears to be working as it should.

Any thoughts on this? Is it a garage issue?

Thanks 2021 D350 Fifty Edition - Carpathian Grey
2017 4.4 SDV8 Autobiography (2021-2024) - Santorini Black
2012 4.4 TDV8 Westminster (2016-2021) - Santorini Black

Sounds like the same problem I had in France recently. I had the restricted performance with the the same error code. It appears that this sensor error is a common fault with the 4.4 tdv8. Mine was replaced by a main dealer whilst in France. Strangely enough they also found that the plastic inlet manifold had split and this also had to be replaced.

Right, have a look at http://www.fullfatrr.com/forum/topic38739.html and particularly http://www.fullfatrr.com/forum/topic38609.html

In a nutshell, Craig recommended changing the sensor because it leads to over-fuelling and the EGR becoming blocked. I spoke to the dealer, the dealer chief mechanic, JLR customer services and did a message to CRC on here.

The upshot is that Craig and everyone else who experiences this fault either says it leads to the EGR being blocked or experiences that happening because when the code is there, the EGR becomes blocked.

JLR used to replace this sensor under warranty but now say that that fault cannot lead to over fuelling or to the EGR becoming blocked (see second thread).

Now, I'm not experiencing over fuelling (doesn't smell of diesel at first start up) but now does appear to be using more fuel in use but not with any smoky exhaust.

As JLR are point-blank refusing to treat this as a warranty claim any longer, I am looking for someone to replace the sensor. When it was a warranty matter, the dealer could only claim for 0.8 hours against doing the job even though it takes 3-4 hours. It might be possible, although highly unlikely, that a dealer will honour the 0.8 hours so I intend finding an independent to do the work.

Unless you have greater success than I of convincing JLR to do the work under warranty.

Thanks Buz1500/GLM

Although the code is the same as yours GLM it seems to be causing a restricted performance issue in mine making it undriveable so I would expect it to be covered by the LR warranty........or am I being too hopeful???? 2021 D350 Fifty Edition - Carpathian Grey
2017 4.4 SDV8 Autobiography (2021-2024) - Santorini Black
2012 4.4 TDV8 Westminster (2016-2021) - Santorini Black

My best guess would be this.....

Depending how the temp probe fails, depends on what message it sends the ECU...

The reason behind the over fuelling is the probe reports back cold and opens the EGR and cold running cycle to the injection system??? (like a choke on a petrol) hence the over fueling and filling the DPF system/restricted performance etc etc

Please remember this is my BEST GUESS

Well, would you believe it.....

Only just been able to get back in the Westie today and the restricted performance message and red warning symbol have disappeared...!!

Took it for a bit of a spin and it's absolutely fine. Plugged in the IID when I got back and the EGR sensor fault is still there but not causing a problem at the moment. If I clear it, it pops back up again. Anyhow, checking live values again it is clear that the EGR on bank 2 is showing 0% even though the ECU command is 20%. Bank 1 is fine. I'm assuming it's more of an issue when the engine is cold, rather than when its been sitting in the sun.

Guess I can only monitor it for now as I can't imagine an LR dealer will bother doing anything if it isn't affecting the car.

Presumably if "restricted performance" issue happens when I am out then as its under warranty LR Assist will attend (won't they?)  2021 D350 Fifty Edition - Carpathian Grey
2017 4.4 SDV8 Autobiography (2021-2024) - Santorini Black
2012 4.4 TDV8 Westminster (2016-2021) - Santorini Black

LR Assistance were brilliant when I used them in May.
They arrived within 30mins.
Plugged laptop in, reset, restricted performance.
Contacted my dealer,
Arranged courtesy car, told dealer to expect me later that day, and followed me for 30 mins to check that I was OK .

Everything was arranged by the time I got to dealer
Ten minutes to book my car in for repair, sign insurance paper, and drive away in brand new RR Sport courtesy car.

That's very impressive service.

Let's hope for a similar thing when I have to call them out.

Was that under an LR Approved Warranty? 2021 D350 Fifty Edition - Carpathian Grey
2017 4.4 SDV8 Autobiography (2021-2024) - Santorini Black
2012 4.4 TDV8 Westminster (2016-2021) - Santorini Black