Land Rover Discovery 4 restricted performance

Hello

I have a problem with my discovery 4. I get a restricted performance message.

Fault codes
P00bd-07 mass or volume air flow A circuit- airflow too high

P1247-00 Turbo boost pressure low

P0235-94 Turbocharger boost sensor A circuit.

The live data from the mafs didn't look that bad.

I tried moving the turbo shut off valve with the scanner and it didn't work

Any idea how to fix this?

Best regards

Looks like you've answered your own question

I tried moving the turbo shut off valve with the scanner and it didn't work

Click to expand...

Resolve that first, then re-scan.

Graculus said:

Looks like you've answered your own question

Resolve that first, then re-scan.

Click to expand...

Any tips on how to do that? Or is it just a replace part situation?

If you want to play 'parts darts' then yes, otherwise, check the wiring and voltages at the shutoff valve, if OK, check the valve can physically move, also carry out a high pressure smoke test, that DTC can be set if there is a charge air leak.

I tried to google but didn't find any really good information. Is there a easy way to access the stuck turbo valve or is it time to dismantle the car?

I would always bow to the knowledge of Graculus on this stuff but if I may, I'll chuck in my tuppence-worth from both his and the OP posts.

If that DTC can be set by a charge air leak, I'd definitely be looking seriously at that first as you have a "DPF differential pressure too high" fault in the 3rd pic of the original post which would normally be a blocked DPF. Having personally caused this issue trying to limp a TDV6 home with a boost hose problem I can say it will over-fuel and very quickly soot up a DPF if you have a boost leak. Another thought on this is that the turbo actuator has been sticking for a while and under-boosting for the fuel delivered while driving. Unlikely that the car would have let that go unnoticed of course.

If you can't clear that DPF issue things will get exponentially worse, if the gas can't escape through the exhaust quickly enough, the turbo won't spool enough and you'll have low boost pressure. Throttle position will command the delivery of the expected quantity of fuel which cannot then combust fully due to the lack of air and as such further soot the DPF.

I've cleaned a couple out now with cans of DPF cleaner (that you put in the pressure tube not fuel additives), hopefully that will bring the differential pressure down enough to resolve some of the issues but of course it will just happen again if you don't get your boost pressure back to where it needs to be. Please don't attempt forced regens though, that's likely to do more harm than good at this point.

The valve is on the left of the intercooler, looking from the front to the rear of the engine bay - it's the greyed out component on the parts drawing below.
The post above is good advice, as well as checking the vacuum lines and vacuum solenoid valve - they are quite common across many marques for failing.