DTC 4-1-4 Boost Pressure Regulation

4-1-4 CHARGE PRESSURE CONTROL

Preconditions for DTC
^ The ECM calculates charge pressure by using the signal from the Mass Air Flow (MAF) sensor. When the ECM considers that the MAF sensor is correct and the load signal exceeds a preset level, DTC 4-1-4 is set.

Substitute value
^ The system only permits initial charge pressure.

Fault sources
^ Defective MAF sensor.
^ Contact resistance in connectors.
^ Break in the lead to the charge pressure reduction from AW 50-42.
^ Clogged hoses between Turbocharger (TC) and TC control valve, and TC control valve and pressure servo respectively.
^ Defective TC control valve.
^ Defective pressure servo to the wastegate valve.
^ Seized wastegate valve.

Fault symptoms
^ When charge pressure reaches the max. limit fuel injection is stopped. As a result, the engine becomes very jerky.
^ Poorer performance from initial charge pressure limit.