This might sound counter-intuitive, have you tried it with the EGR blanks removed?

ETA - it's a basic check, but what is the supply voltage at the sensors? it should be within 4.75 - 5.25VDC although personally I'd investigate if it was outside of 4.85 - 5.15VDC. I'd also look at all the pressure & temperature sensor values, with the engine not running and ignition on, all pressure values should be broadly the same - i.e. atmospheric pressure, temperature values should also be close to ambient, beware of false positives on IAT as they are hot film and will read high if there is no air being drawn across them, so initial key-on values will be correct, after a few minutes, expect them to have climbed close to 30deg. C.

Last edited by Phoenix on 23rd Nov 2022 10:28pm. Edited 1 time in total

The fault was the there before and after the blank

At what point were they blanked? have you tried removing them since the LR software was reapplied? there's a lot of balls in the air here....

No not removed since LR software was reapplied.

The LR tech said all readings were correct when they checked after software flash.

What was the reason the vacuum valve was replaced? was there a defect or just a 'try this' type of reasoning? I'm just wondering if there was a defect, if it's worth checking again.

With regard to the EGR's, I'm wondering if the engine management is detecting (or rather not detecting) no expected change in charge air temperature when it expects the EGR to be open and is self-limiting boost for engine protection.

RRR4J wrote:

The LR tech said all readings were correct when they checked after software flash.

Hi, the vacuum solenoid was easily accessible so it was just a try it out.

I will try and see if I can use my mobile obd app to read the values myself rather than the tech. I'll get back to you on that one.

Not so sure about EGR, because the fault was there when there were not deleted and still there after blanking and deleting.

Really appreciate your input. Thanks

When I say 'common sense' checks, I mean are the live values plausible? for example boost pressure should be close to ambient pressure with the key on, engine off, if ambient is 1000kpa and the boost pressure is reading 1005kpa, that's fine, if it's reading 1050kpa (or 980kpa), then clearly there's an issue. the same goes for temperature, although a warm engine will obviously have different temperatures in the charge air path to ambient, it's mainly to make sure the readings make sense for the conditions.

Hi chaps, I’ve recently moved into an L322. 3.6 08. I’ve done a basic oil and filter service, and replaced the air filter with a K&N filter. While I was in there I cleaned the sensors. I’m now seeing a fault code: P023D-22 (2C) Manifold absolute pressure - turbocharger/supercharger boost sensor A correlation - General signal failure - signal amplitude>maximum. On IID.

Intake hoses look like they are newish as labels were on them! Any ideas on this code please? Would a K&N cause this?
It’s only happened a couple of times cruising on the A roads.

RRR4J wrote:

Hi, I have an unusual fault that causes my car (2007 vogue se 3.6 tdv8) to go into limp mode, only when either going up a very steep hill (holds the gear and doesn't drop down to help keep going up) OR when on the straight and needing more power to over take for example, usually around 30mph - 50mph or when just flooring it from take off, but this is intermittent and if the car is already at speed its fine. It feels as though its only when needing that extra boost or gear change to help with the power load.

Only fault code that comes up is p023d (22). NOW here's the unusual thing that even the LR tech and indies can't understand. When it goes into engine fault mode, I stick it in neutral and whilst rolling, turn the key once off and on again, bang it back in D and then the car will carry on all the way to Scotland, tackling any hill, without the fault happening again. Only once I park up and switch off the car, remove the key and then if taking back on a new journey, it will happen again. Intermittent.

I have checked all the associated diagnostics with that fault code and now have no where else to turn.

The car has had:
* new turbos
* all new boost hoses
* new inlet manifold
* new map and maf sensors
* sensor readings all correct
* high pressure smoke tests
* ecu flashed at dealers
* egr blanked
* no oil leaks
* gearbox oil changed
* vacuum pipes checked
* vacuum solenoid changed ( this was the only time it made a difference to the car, it was dropping a gear down when going up hill or needing more speed to overtake but for only 6hrs then the same happened again )

Anyone, help will be very very much appreciated. Thanks for reading.