Check the vacuum supply system components/functions: in particular, check for leaks or blockages.

Check the seal of the secondary air inlet/turborcharging system hoses.

Also check for any obstructions or porosity.

Check for leaks in the intercooler.

Check that the pipe restriction bands in the air intake/inlet system are correctly fitted.

Check the hoses and pipes connected to identify any obstructions, damage etc.

Check that the flow meter is not contaminated.

Check the exhaust gas turbocharger and exhaust system components/functions

If possible, renew the pipes. Otherwise replace the faulty components

Op. 1048A VACUUM AIR CIRCUIT

Replace the filter element

Op. 1048A14 AIR CLEANER FILTER ELEMENT - REPLACE.

Refit correctly

Op. 1048A14 AIR CLEANER FILTER ELEMENT - REPLACE.

Turn the ignition key OFF.

Disconnect the vacuum hose from the vacuum pump

Connect a pressure gauge between the vacuum pump and the hose (see following figure).

Start the engine, adjust to idle speed and check that the reading on the pressure gauge is between -0.7 and 1.0 bar

Replace the vacuum unit

Op. 3330D30 VACUUM PUMP - R+R

Turn the ignition key OFF.

Reconnect the hose to the vacuum pump.

Disconnect the vacuum hose from the turbocharge actuator solenoid (see following figure).

Connect the pressure gauge between the solenoid and the hose.

Start the engine and adjust to idle speed.

Select the following control unit at the diagnostic equipment: EDC16C39 Diesel electronic injection control unit.

Carry out the following active diagnosis: Turbo regulator, ensuring that it is successful

Replace the solenoid valve

Op. 1064B42 SOLENOID CONTROLLING TURBOCHARGER VANE POSITION ACTUATOR - R.R

Check the turbo pressure control solenoid is operating correctly

See Test 1064BB CHECK ON OPERATION OF SUPERCHARGING PRESSURE SOLENOID VALVE (PIERBURG)

Turn the ignition key OFF.

Reconnect the vacuum hose to the turbocharger actuator solenoid.

Start the engine and adjust to idle speed.

Select the following parameters in the parameter screen: EGR valve opening and measured Air Mass.

Set conditions where the EGR valve is open and check that the intake air mass is between 20 and 40 kg/h

Check the exhaust gas recovery solenoid is operating correctly

See Test 1080CB E.G.R. SOLENOID FUNCTIONAL TEST

Then return to idle speed.

Set conditions where the EGR valve is closed and in these conditions check that the intake air mass is between 40 and 60 kg/h

Replace the flow meter

Op. 1060G10 AIR FLOW METER - R.R.