Vw 56 2018 high pressure boost code p023800

[Courts1312]

VW Transporter T6 2018 – Boost Pressure Nightmare… Any Ideas?

Hi all, looking for some advice because I’m honestly hitting a wall with this one.

I’ve got a 2018 VW Transporter T6 2.0 TDI (not even at 60k miles) and out of nowhere it started throwing low boost pressure faults. Then, without me changing anything, it switched to high boost pressure faults instead.

Here’s what’s been done so far:

• Boost/MAP sensors replaced (both genuine parts)
• Solenoids replaced
• Auto electrician checked it – said it was the sensor, but they’ve been replaced both after he said it was that
• Turbo checked – confirmed perfect
• Smoke leak test done – no leaks at all


At this point, everything that should cause low or high boost has been checked or replaced, and the van still isn’t happy.

It’s honestly baffling because the van is low‑mileage and well looked after. If anyone has had something similar or knows what direction to look in next, I’d massively appreciate the help.

Thanks in advance!

 

[mmi]

The P0238 is not exactly about high boost pressure but rather about too high signal (out of range).

P0238 00 - Manifold Pressure / Boost Sensor (G31) - Signal too High​

Can you read with your tool what the actual sensor reports, both pressure reading as well as raw voltage as seen by ECU?

I would first check the wiring of G31 as "signal too high" suggests open ground circuit.

 

[Courts1312]

Thanks for the reply I will have a look at that
And no I don’t have a tool that can do that but my bother might will ask him
Thanks