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Please advise expected MAP value on scanner


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2007 1.8 tdci focus

Am suffering from low boost fault code P0299.  Have read lots of posts to try and get to the bottom of it (checking hoses etc, fully serviced)

I have checked the engine inlet pressure with a digital gauge and it agrees with the MAP sensor.

When idling it is reading 100 kpa (pretty much atmospheric). When driving the highest reading seen at about 3000 rpm is 130 kpa.

Can anyone with the same engine and a scanner advise what values I should be seeing. I was expecting to see a significant negative pressure when ideling.


Generally the car runs ok but lacks power/accelleration


Thanks in advance



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28 minutes ago, Tornados said:

When idling it is reading 100 kpa (pretty much atmospheric). When driving the highest reading seen at about 3000 rpm is 130 kpa.

My 1.8 reads about 2.4Bar (240kPa) on full boost. That is about 20psi above atmospheric, which sounds right to me.

A Forscan trace including MAP from my car is below. APP is accelerator pedal, FRP is fuel rail pressure, VSS is speed.

130kPa is badly wrong. If you have checked the simple bits like air filter & hoses, then it is likely to be either the turbo actuator, or the turbo itself, I guess.

If I recall, Forscan can display a PID for turbo actuator demand signal, or turbo actuator position. That might help.

It is just possible it could be a fuel or fuel pressure problem, but I think turbo boost is mainly a function of the vane position and rpm. The extra heat & volume from the burning fuel will only have a small effect.



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Thank you Peter. This is exactly the information I required!

I think I may upgrade to Forscan on my PC. I see there are some modified scanners on ebay for the EL... mode.  I am going to try and have a closer look at the turbo.


Thanks again.


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3 hours ago, Tornados said:

I see there are some modified scanners on ebay for the EL... mode. 

The Tunnelrat ELM327s have been reported to work well by several people, and are stated to be compatible with Forscan and ELMConfig.


Forscan works best on a Windows laptop, with a USB ELM.  Forscan is also available for iOS & Android for some tablets & phones, using USB if available, or bluetooth or WiFi ELMs. But there are some limitations.

Wireless ELMs are often not as reliable as the wired ones. Also they are rarer in the "modified" form which is needed to access the 2nd Ford bus system. This 2nd bus is the MS-CAN bus, and links all the car interior electronics like door modules, and the BCM (aka GEM). But a standard ELM will still work with all the Underbonnet Modules (PCM, ABS etc) and with the IC (Instrument Cluster).

The Forscan programme is free (in Windows format) and you can get it from:


It is reasonably easy to use Forscan to log data while driving. Connect, set up a list of PIDs to monitor (not too many), put the computer somewhere secure, where any wires will not interfere with driving. Start logging, you can select graph mode, but it does not matter at this stage. Take the car through its operating range, on a journey from a couple of minutes to about an hour (the file starts getting inconveniently big after about 30 minutes). No need to look at the computer at all during this.

Stop & park, stop logging, save the data. Then you can review it at leisure.

That is about the only way to fully test a turbo, without a dynamometer.

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