P006A-00, P00BD-07, P1247-00 & P0235-94 Faults on my Disco 4

[pandlsm]

Model L319 - Discovery 4 2013 109K
The dreaded red triangle and Restricted Performance occurred last week after accelerating off a traffic light change. Plugging in the IID tool revealed the following errors:

P006A-00 (27) Manifold absolute pressure - mass or volume air flow correlation,
P00BD-07 (27) Mass or volume air flow A circuit range/performance - Air flow too high - General failure information - mechanical failure,
P1247-00 (27) Turbocharger boost pressure low, and
P0235-94 (27) Turbocharger/supercharger boost sensor A circuit - Component failure - unexpected operation

Researching the fault and possible easy to get to fixes I visually checked for hose and pipe leaks on circuit A, cracks in the manifold (paper test) and throttle body but there was nothing obvious. I then removed the secondary turbo re-circulation valve and shut off valve getting about 1/4 cup of oil from the bottom pipe (the oil drain mod had been done on this model). I cleaned the valves and checked the solenoid and compressor shut off valve were working properly before reinstalling it. The vehicle started ok, no smoke from the exhaust so I cleared all the engine faults.

Testing the vehicle it ran fine on the primary turbo for a few kms but when I drove up steep hill in 2nd gear the second turbo appeared to cut in at 2800rpm but straight away with a jerk the car went into Restricted Performance again. Back home I cleared the faults and checked the vacuum hoses and tested the turbine intake shut off solenoid and charge air solenoid and both appeared to be working. Another short test drive and car coughed and sputtered a bit then went into Restricted Performance again. The faults above were cleared again and I did some live tests on while in the driveway just revving the engine but everything appeared to be ok. So I booked in with a Indie for a check over in a couple of weeks and left the car in the driveway for a couple of days.

This morning I decided to go for another test drive. After checking for faults and finding none I headed out into the suburbs. This time everything worked! I drove around a bit to warm up the engine then hit the big hill in 2nd gear, the second turbo cut in at 2800rpm and the car powered up the hill going up to 3600rpm before reaching the top and having to slow down.

I couldn't believe it so I repeated test 3 times and everything was fine. The IID had no faults and it appeared Restricted Performance had never occurred.

Thinking about the problem led me to consider that the vehicle is largely driven around town and when I do go bush I tend not to rev the vehicle past 2500rpm (timid driver) so the second turbo rarely gets used. I have to assume that a build up of oil in the shut off valve may be a clue and that giving the car a good work out with high revs cleans out the second turbo and gives the solenoids and vacuum system some action.

Any thoughts appreciated.

[Eric SDV6SE]

Good systematic check of all known sources of this issue. You may want to remove and clean both MAFs, just after the airbox and the MAP at the top of the Y piece. With the oil drain mod done you should not be getting much oil in the air control valve or intercooler piping.

They do need an "Italian tune up" now and then to blow the soot and crud away.

[mtthsk]

Hi pandlsm,

did you have this problem re-appear?

Cheers,
Matt

[Andych]

So, thanks to this forum I have managed to (hopefully) solve my issue with Restricted Performance on my L320 (2010 3 litre Twin Turbo Diesel). I started out as intermittant so I didnt pay much attention to it and then it happend again recently and didnt really go away. I could drive it but had to be very gentle on the throttle otherwise it would just bog right down and actually be dangerous.
It also had a very distinctive whine, especially when you lifted off the throttle.
I had some spare time earlier this week so connected up the GAP tool and ran the fault codes... Low and behold P006A-00, P00BD-07, P1247-00 & P0235-94.
While some interweb searches all related to inlet manifold issues I was pretty certain that wasnt the issue as the top of the engine is a bit dusty but absolutely oil free.
Then I happened across this thread and decided first port of call was to check the Turbo Bypass Valve.
Once I had the plastic cover off readed up to feel the actuator and it popped back into position...
So off it all came. The actuator rod almost seemed to be catching slightly on full actuation the first feww times I manually moved it so I removed the actuator, removed the arm on the valve (mine is still the old style with the nut retaining the rod to the arm) and cleaned it all and applied some high melting point grease to the arm and around the actuator, reassembled.
Cleared the codes and took it for an extended test drive including some Freeway sprints from low speed up to 110km under full and then partial throttle.
It is like a new car.. the engine seems much happier and pulls like a train so hopefully all is now fixed.

[Dustin96]

Hi, i?m in uk and i have these codes P006A-00, P00BD-07, P1247-00 & P0235-94. i dont know what could be the issue?! Please help