T8 / P0033 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Fault indicator lamp (for further information see WIS Fault diagnosis, general)
Limp home
System Bypass, charge air control, malfunction
Fault symptom
Fault indicator lamp (for further information see WIS Fault diagnosis, general)
Limp home
On-board diagnosis
Type of diagnosis:
Enable criteria:
| Battery voltage must be between 11 - 16 V. |
| NONE of the following DTCs must be detected: |
| Engine speed less than 3500 rpm. |
| Output to solenoid valve is inactive. |
| The boost pressure should be more than the atmospheric pressure + 35kPa. |
| Intake pressure should be less than or equal to 35 kPa. |
| When the conditions are fulfilled, the values for boost pressure and air mass are stored for evaluation. |
Fault criteria:
| When the average values for boost pressure and air mass exceed 1.3 kPa and 2.4 g/s, respectively. |
Dependent:
System reaction to a fault:
| Torque limited to max. 170Nm. |
| Boost pressure adaption is blocked and reset. |
| Boost pressure control is blocked. |
| The system continues to function with a calculated air mass instead of the value from the mass air flow sensor. |
OK report:
| When the average value for boost pressure and air mass is below 0.6 kPa and 1.3 g/s, respectively. |
Fault handling:
| (See section Fault handling III, "Other emission-related components and functions" for more information.) |
Checking the wiring harness
Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.
Diagnostic help
Diagnosis regards:
| The vacuum section of the system and the function of the valve. |
| The by-pass function is checked when the accelerator pedal is rapidly released during moderate acceleration. |
Functions in the diagnostic tool related to the fault:
| • | Absolute pressure sensor, charge air |
| • | Manifold absolute pressure sensor |
| (See also description of readings/activations in diagnostic tool) |
