hi, i have read alot of things relating to this problem but no one seems to have put a resolve to it. My Mondeo is a euro 4 2.0 tdci on a 55 plate. when my car has been stood for a few days the car would go into limp mode and the engine management light would come on, when this happened the Turbo would give no boost and the exhaust sounded like it was blowing. However the fault has got worse, as it is doing it all the time. I have cleaned out the EGR valve and the MAP sensor. The fault code that comes up is P0235. I have removed the actuator rod from the electrical turbo actuator and the turbo arm is free as a bird. I cant see any signs a air leaks on the EGR valve to MAP sensor pipe. Any ideas????

35 minutes ago, mondeo10101 said:

The fault code that comes up is P0235

Hi,

P0235 refers to Turbo Boost pressure. I suspect this is the same as the MAP (Manifold Absolute Pressure), since the inlet manifold pressure is the Turbo Boost Pressure. Check there is only the one sensor.

In principle it is easy to test the pressure sensor. They usually have 3 wires: ground, +5v, and a voltage output signal. With the ignition on, (to power the sensor) but engine stopped, the output voltage is usually between 1 & 2v. When the engine runs fast enough to give some turbo boost, the output voltage should rise. If the output voltage is stuck up near 5v, or low, or does not rise with pressure, then it is faulty.

The hard part is actually making contact with the wires, without some sort of breakout adapter. I have been known to use a pin or scalpel blade (carefully!) to pierce the insulation and contact the inner core. The other voltmeter probe goes to a good, clean point ground point on the engine.

It is possible that a programme such as Forscan can monitor the pressure reading live via the diagnostic socket. Info is on other posts in this forum, or I can post some here if you want.

I rather hope it is the sensor or its wiring & connectors. If not, then PCM & Turbo are possible suspects, but the code is fairly specific to the sensor.

Please post any feedback here.

Peter.

 

electric actuator quite common to be the issue.

12 hours ago, mondeo10101 said:

The fault code that comes up is P0235

Ian is probably right, he usually is! (Turbo actuator fault)

But personally I would still test the pressure transducer 1st, because it is relatively easy. Rule that out before tackling the Turbo.

Peter.