Engine management and stability light on same time
 

Hi, Help please!!!!
I have a 2009 2.0d 2.0 MZR-CD engine (I'm fairly sure) Stability control light (car with skid marks) and engine management light comes on about 35miles after being reset and both at the same time.
Fault codes:P0299 (boost pressure low) and U2023 (Fault received from external node)
Little to no thrust in high gear and feels sluggish in low
Over the past few weeks it has cleared itself but come back again shortly after. I had the egr valve cleaned and faults cleared but again after about 35miles back on again......
Can anyone advise?? Ive read it could be the VGT solenoid on the turbo, any thoughts??
Thanks in advance

2009 What?

Direct from the Mazda 3 BK series Workshop Manual.

DTC P0299

Turbocharger underboost condition

DETECTION CONDITION
• The PCM monitors the intake boost pressure using the boost sensor signal. The PCM compares the intake boost pressure of target and actual. If the PCM detects that difference between target and actual intake boost pressure more than 60 kPa {450 mmHg, 17.7 inHg} for 9 s, the PCM determines that the underboost condition.
POSSIBLE CAUSE
• Boost sensor malfunction
• Boost sensor improper installation
• Turbocharger malfunction
• VBC control improper operation
• Air leakage in intake-air system
• PCM malfunction

Thanks for the reply grim.... appreciated. Its a Mazda5

I think the stability control light is the problem with in turn is triggering the engine management light with in turn is putting the car in to some sort of safety mode with less power which brings up the p0299 code (under boost). Do you think this is plausible??

Are there any checks I can do on the turbo to eliminate it or on anything else before the garage start replacing parts on a trial an error bases??

If you go to a Mazda dealership they have the rest of what I posted from the workshop manual to pinpoint the exact problem without throwing random parts at it.

Another of my 2 cents worth.

Hi, Thought I had resolved this by getting the EGR cleaned and rear wheel bearing changed but its back after about 3 weeks. It went out on its own a short while after it had been in the garage.
I filled the tank this morning to almost full and hit the motorway, about 5 miles down the road both lights back on. I've done about a 30 miles round trip and checked this eve, both lights still on.
If I recall correctly the lights have come on just after filling the tank up well over half a tank on previous occasions. Am I clutching at straws here???
Oh and Mazda want £90+ to do a diag which may or may not tell me what the exact problem is.