My local RR dealer changed my gearbox a few months ago and a few kilometes later I got engine failure (emergency mode). When I stop and restart the engine, it works like a charm for a few minutes or maybe up to a couple of weeks.

Lynx Diagnostics tells me it is: "P-2469, Exhaust gas temperature sensor circuit high (Bank 2 Sensor 3)"

When I look under the car, the rearmost temperature sensor on the right hand side exhaust pipe, near the rear end of the gearbox, have the cable stretched like a violin cord. I moved the cable a bit but it didn't help. My dealer replaced the sensor at no cost but that didn't help either. They also checked one or more connectors without finding anything wrong.

One strange thing they told me was that they were not 100% sure it was that sensor!?!?!? To me, Bank 2 seems reasonable to be the right hand side and sensor 3 the third one (rearmost) in that exhaust pipe. I believe there are 3 sensors for the DPF/Catalyst, 2 temperature and one pressure.

The failure ALWAYS "repair it self" by stopping and restarting the engine and sometimes it also triggers the "Check engine" light but usually not.

I can't read out the sensor values in Lynx, that might give me a good idea what is causing this problem.

I recently had a 800km drive one day with a fairly light trailer and got in emergency mode 30+ times. It seems to be more frequent during/immediately after long steep hills (like 3-5 km uphill at 9%) but may also happen with cold or warm engine on level ground.

When the gearbox was changed, the whole exhaust system was removed and there are one small leak in one of the connections but it seems too small to make a difference.

Any idea where to go from here? "Plentraktoren/Garden tractor": 2008 L322 TDV8
"Project": 1990 90 County 300tdi

The symptoms have increased so I had to do some more work...

Discnnectd the suspected right hand post-catalyst temp sensor and a few kilometers later I got another error message: "P-0101 Mass or Volume Air Flow Circui 'A' Range/Performance - Circuit Voltage above treshold."

Didn't make much sense to me so I crawled under the car with my multimeter and checked both post-catalyst temp sensors. The suspected right hand sensor gave a reasonable reading in the area 1300-750 ohm depending on the temperature but the left one was a clear open circuit... Bingo

Ordered a new one but the big question is how to get the old one out? Tried to use some force but it didn't move. Stainless steel can be a pain in the butt... Have had some FluidFilm lanolin on the threads, maybe not the best lubricant but it penetrates extremely well.

Any good ideas? "Plentraktoren/Garden tractor": 2008 L322 TDV8
"Project": 1990 90 County 300tdi

Problem solved. Impossible to remove the old temp.sensor, by using some force with a 14mm spanner the hex-part of the sensor snapped off.

I ordered a new sensor but I ordered the wrong one so the cable was way too short. Cut the exhaust pipe in the middle of the straight pipe where it goes from the side of the car and towards the center, easy place to reconnect it with an exhaust sleeve. Located a nice spot before removing the pipe and welded in a new nut about 20 cm further back.

Still working like a charm

The "post catalyst sensor" I ordered is the one after the catalyst but before the DPF. I should have ordered "post DPF" or whatever that one is called.

I read somewhere that the air flow sensors is used to optimize the gearshift and after cleaning the sensors, the shifting got noticeably smoother, no dramatic change but definitely smoother. The sensors didn't look very dirty but a good spray with Arrow Super Solve elctronic cleaner did the trick. "Plentraktoren/Garden tractor": 2008 L322 TDV8
"Project": 1990 90 County 300tdi

i cant recall anyone else having this problem, hence the lack in 'reply' posts but its great that you've sorted it.  ... - .- -.




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