PRE-RELEASE
Boost pressure control valve
| Boost pressure control valve |
The task of the boost pressure control valve is to convert electronic instructions from the PSG 16 control module to control a negative pressure that can act on the wastegate diaphragm. The negative pressure is taken from the engine vacuum pump, which always generates a pre-determined negative pressure.
The boost pressure control valve is connected to a vacuum tank to allow more accurate control. The vacuum tank also enables more reliable control at high altitude.
Pin 2 of the control valve is connected to pin M13 of the control module and pin 1 is supplied with B+ from fuse 14.
The control valve is grounded through control module pin M13 with a 140 Hz PWM pulse. The timing ratio determines the magnitude of the negative pressure in the hose to the wastegate by which means the position of the regulator rod can be controlled.
| Diagnostics |
If the control module output is shorted to B+, DTC P0246 is generated.
If the control module output is shorted to ground/open circuit, DTC P0245 is generated.
If the actual boost pressure is too low compared with the desired boost pressure, DTC P0244 is generated.
If the actual boost pressure is too high compared with the desired boost pressure, DTC P0243 is generated.
System reaction to a fault
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The regulatory functions for exhaust gas recirculation, swirl throttle and charge air are switched off.
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Boost pressure control is controlled with a constant value.
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Power reduction. Torque limited to:
200 Nm up to 2000 rpm 170 Nm up to 2250 rpm 120 Nm up to 2500 rpm 70 Nm up to 3000 rpm |
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CHECK ENGINE
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