Dennis I had a similar code P-2459-65 (2a) and then (6c) variant with same words before mine was fixed by the thermostat. CHeck your wiring underneath perhaps for either pinching/fraying or loose connection?

H Dolphinboy I have a new coolant sensor on order as this was my next port of call going on your earlier recommendation. I will have a good look at the wiring whilst replacing and see what I find. On a positive note I did manage to fix the windscreen wiper, it had popped off the assembly arm and just needed to be clipped back in place 2011 TDV8 Vogue SE

Dennis, am thinking at all the long shots now. Take them with a pinch of salt.

it may be something like inefficient diesel injection pressure into the exhaust not giving a high enough temp to fully clean.
It may be a low exhaust pressure, hole in exhaust? (Have you had a pressure test on the DPF done?)

this from a Ford engine specialist:

Potential causes for this code (P-2458) to set are:
Insufficient diesel exhaust fluid/Incorrect diesel exhaust fluid
Shorted or open wiring to the DPF injection system
Defective PCM or a PCM programming error
Defective DPF pressure sensor Faulty exhaust pressure sensor

Read more at: https://www.obd-codes.com/p2458

Quote:

Defective DPF pressure sensor Faulty exhaust pressure sensor

Hi Dolphinboy, any options are currently considered so any pointers are always appreciated

GGDR - Voltages are all good and within the regions you’ve quoted. Car was sat at cruise doing 65MPH on a quiet motorway with a full tank of fuel. It’s odd that by now I should have the amber DPF message but currently this isn’t showing. The car is asking for a regeneration to be performed as I can see the demanded regeneration count go up but not excessively. Oil dilution is also below 7. 2011 TDV8 Vogue SE

Let’s work together on this. Family friends 2011 4.4 tdv8
Amber DPF warnings - regular and clearing even after 40miles

Error code:
P2458-66 DPF regen

Click image to enlarge

Click image to enlarge

Sounds like a plan to me, happy to provide any input I can from my own tests carried out so far. 2011 TDV8 Vogue SE

This is the current state of my DPF, sadly you cannot see the rear end due to the design which is probably where most of the ash blockage would be. To be honest I was surprised it looked as clean as this as my reading is now in the red, although you can see a thick deposit at the lower edge.

Dolphinboy wrote:

@Dennij.

Well we may have found the problem.

The Thermostat housing was damaged (possibly when another dealer fitted a new inlet manifold in Feb) and reading high which meant that the engine was running cold and therefore not able to sustain the high temps to keep a regen going. The thermostat was giving a false reading of 105 degrees (should be 98 ) and keeping open and initiating the Fans (I had noticed the fans came on very quickly and often but was told by another LR indie "oh they all do that" ). The engine Temp sensor was also kaput and reading higher than the real temp. This meant the the ECU was trying to initiate regens and not able to due to low temps.

These sensors have been changed along with the oil cooler (was leaking into coolant) and it now appears to be working ok. The LR indie initially went for a drive for over an hour and a half to get the temps high enough (high revs and big load going uphill) and got it to regen correctly, monitoring the temps on a laptop as he drove. that's how he identified the poss cause.
.

Did he (Steve Norman?) change the entire thermostat housing or just the engine coolant temperature sensor (ECT) on the front of the housing?? Is there more than one sensor as you use the plural "sensors"?  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
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dennij wrote:

Why have you got EGT in Volts and not Temperature? Temperature is the normal field we choose I thought?

ECT Sensor in Volts = is this a normal figure (0.357) at 92 'C? Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

Well spotted, I hadn't even noticed as normally I have the temps. I was probably working through the diagnostics sheet in the WM and checking voltage was within the range during the regen. What I have noticed though is that when the regen takes place, the time scales don't add up as I would see the temp drop from 600c + after a few minutes and it would hover around the 400 - 550 mark for a while, then back to 600 plus and so on until it had had enough and would appear to want to have a rest and the temps would drop back down again. Some time later off it would go again so this may be worth checking on your friends RR too. 2011 TDV8 Vogue SE

Normally I have temps

Click image to enlarge

@dr Rob.

He changed the thermostat, the housing and the engine temp sensor (LR Part no. LR044930)

OK, thanks. Is yours now running ok Dolphinboy? Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

Yep Rob. Faultless. Steve just said he worked down through all the possible options until he hit the one that made the difference.

Last edited by Dolphinboy on 24th Mar 2021 10:03pm. Edited 1 time in total