Volvo All Engines (2010 Emissions) Fault Code: SPN 1127 FMI 18 PID: PSID 98 Engine Turbocharger 1 Boost Pressure

The engine control module (ECM) monitors the intake manifold pressure (IMP) sensor and controls the boost air system (mainly controlled by the VGT) and the engine turbocharger compressor bypass valve. The ECM also uses parameters like engine speed (RPM) and turbocharger speed to make a calculation of the IMP. This estimated value should not differ too much from the measured value.

Conditions for diagnostic trouble code (DTC):
1) Charge pressure Low

Observable symptoms
1) High soot level
2) Low Power

Probable cause
1) Charge air system leakage
2) Turbocharger
3) Charge air pressure sensor
4) Air Cleaner (ACL)
5) Faulty VGT position – The sensor shows a more closed position than the actual position
6) Faulty EGR position – Valve more open than it is supposed to