Restricted Performance RRS as second turbo comes in

Restricted Performance RRS as second turbo comes in

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croftsj

Original Poster:

373 posts

241 months

Monday 10th June
quotequote all
Had a Restricted Performance warning/alarm pop up a couple of times in the last few weeks, luckily didn't put me at risk when they popped up and held me to c45mph. The turn off wait 60 seconds and go again got me going. Last week I took the car into a specialist for an oil service and a bit of diagnostics around the issue.

Long and short of it is they ended up replacing the throttle body MAP sensor which was beyond a good clean.
Road test failed to reproduce the fault which kicks in around 3-3500 rpm as the second turbo comes into action. Personally I don't think the technician was trying hard enough to replicate but it's improved throttle response no end!

Today it's happened again, I deliberately provoked it and hit 4,000 rpm or there about the Restricted Performance alarm came in 200 yards from home, with the engine running, fault still present and a diagnostic tool plugged in I get:

P004B Turbocharger/Supercharger Boost Control B Circuit Range/Performance
And
P259B Turbocharger Boost Control Position Sensor B Performance - Stuck High

Whatever you do don't go Googling these faults as you'll end up in another dimension believe me. I think this could be one of 3 things. Failed sensor, stuck vanes, damaged wiring to sensor or 2 or 3 of them combined.

I believe the 'second turbo' is the drivers side on RRS L494?

I'm no motor mechanic but my gut feeling is this isn't time for a new turbocharger and putting labour aside could be a clean sensor job, a replace sensor job, overhaul/clean inlet vanes or a bit of wiring to replace. With the way the MAP sensor inlet was coked up I wonder whether it's the same with the boost control position sensor?

Any thoughts welcome. Thanks.

stevemcs

8,766 posts

96 months

Monday 10th June
quotequote all
Which engine ?

croftsj

Original Poster:

373 posts

241 months

Monday 10th June
quotequote all
3.0 TDV6

NomduJour

19,260 posts

262 months

Monday 10th June
quotequote all
Is the actuator sticking?

croftsj

Original Poster:

373 posts

241 months

Monday 10th June
quotequote all
Well I guess this is the question, is it a mechanical actuator sticking or is it a sensor that thinks it’s stuck open.