Checking the Boost Pressure Control Valve
Boost Pressure Control Valve Diagnosis, Steps 1, 2, 3:
1 Connect an ISAT scan tool, contact the SFI system and enter command code 3020.
Check that the boost pressure control (BPC) valve is working by listening to it (note: low noise level!) or by feeling it vibrating (at a frequency of 8 Hz).
(A physical check of the BPC valve can be carried out as follows: blow into the valve connection to check whether the washer between the valve's poles has jammed, e.g. due to a coating of oil from the crankcase ventilation system. If the BPC valve is faulty, replace it.)
2 If it is not, turn the ignition switch to the Drive position and check that fuse FA5 is intact and that voltage is present up to the fuse holder.
3 Unplug the valve's connector and check the resistance across pins 1 and 2 and also across pins 2 and 3 of the valve. In both cases the resistance should be about 3 ohms.
If it is not, replace the boost pressure control valve.
NOTE:
When command code 30XX has been used, the car cannot be started for the following 12 minutes. Use command code FF00 to clear the function, following which the car can be started.
Boost Pressure Control Valve Diagnosis, Steps 4 & 5:
4 If the BPC valve is OK, turn the ignition switch to the Drive position and check that battery positive voltage is present on pin 2 of the valve's connector.
If it is not, switch off the ignition and check the lead between pin 2 of the valve's connector and the fuse holder (fuse removed) for continuity/shorting to ground.
5 With the ignition switched off, connect a break-out box to the ECM wiring harness (ECM disconnected).
Check the wiring from pins 2 and 26 of the ECM to pins 3 and 1 of the BPC valve's connector for continuity/shorting to ground.
Remedy faulty wiring and/or connectors or continue as described below.
6 If problems/fault symptoms persist in spite of the above checks and possible road testing, ECM may be faulty. Review "Before Replacing ECM."
NOTE:
If repeated pressure monitor operation has been caused by excessive boost pressure (such as due to a defective solenoid valve), maximum negative adaption will be obtained. This means that normal maximum boost pressure will not be attained. To attain maximum boost pressure, disconnect and reconnect the control module and carry out adaption as described in "Adaption of Charging Pressure."