Fault code P1470-032

[dokalj]

What is this fault code?

It has come up on my ML and it will not go past 3000revs?

I thought it was the MAF.

Disconnect MAF, no change.

Re-connect MAF, Revs to 4500 and beyond.

Then it limits back to 3000revs.

Take MAF out, clean, re-install. Revs return back to normal.

I have not checked this afternoon, fingers crossed.

Just really wondering if above is definately the MAF.

Thanks

 

[sinewave]

P1470 Charge pressure control On/off ration of actuation is too large.
P1470 Charge pressure control Open circuit
P1470 Charge pressure control Positive control variation [Charge pressure is too high.]
P1470 Charge pressure control Positive control variation [Charge pressure is too low.]
P1470 Charge pressure control Short circuit
P1470 intake air pressure regulation
P1470 Intake pressure or boost pressure control

 

[sinewave]

Turbo problems, could be leaking hoses, the pressure sensor or failing electrics on the Turbo it's self.

 

[dokalj]

I have been told it is the following fault from the list above:

P1470 Charge pressure control Positive control variation [Charge pressure is too high.]

 

[dokalj]

What does this mean?

 

[dokalj]

I took the car for a drive and it was good then suddenly started to restrict itself again

 

[sinewave]

Needs a STAR equipped Indie TBH

 

[dokalj]

Really? I thought MB Star machine would be fine.

Thanks for your input.

 

[BlackC55]

Sounds like excess boost. I would be looking at the vac transducer, split vac hose. Vvt vanes sticking. Etc etc

 

[dokalj]

Thanks Olly, is the transducer on the O/s front near the black sphere?

I did find this thread, which says glow plugs cause a similar problem:

ML270 Speed Lockdown - Page 2 - Mercedes-Benz Owners' Forums

 

[BlackC55]

No. It's a electro vacuum unit with an electrical connector and vac pipes to it.

You need proper diag to investigate this one.

 

[dokalj]

No. It's a electro vacuum unit with an electrical connector and vac pipes to it.

You need proper diag to investigate this one.

When you say proper diag...do you mean Star Diagnostics? MB put the car on star for me and told me the fault code.

I pulled the vacuum pipes off today and put them back on. The car was reving over 3000revs...I then parked up and tried it again and its limited to 3000revs.

I then switched off and it cleared and then came back.

 

[BlackC55]

A Star won't tell all. It's good but it needs a good operator too.

Fault codes can mean bugger all without proper testing.

 

[dokalj]

A Star won't tell all. It's good but it needs a good operator too.

Fault codes can mean bugger all without proper testing.

Cheers Olly,

Looks like a bigger job than I anticipated.