TEST
ACTION
APPLICABILITY
6
NOTE: This engine system utilizes three solenoids to control turbocharger
operation. Perform the following four Solenoid Tests on each of the three
solenoids one at a time.
Turn the ignition off.
Disconnect the hoses from the appropriate Solenoid.
Install a plug on the Solenoid hose B connection point.
Connect a vacuum pump to the Solenoid hose A connection point.
With vacuum pump apply 20 inches of vacuum to the Solenoid hose A connection
point.
NOTE: Vacuum reading should not drop below 10 inches within 5 seconds.
Does vacuum read above 10 inches for at least 5 seconds?
All
Yes
→ Go To 7
No
→ Replace the appropriate Solenoid.
7
Turn the ignition off.
Disconnect the hoses from the appropriate Solenoid.
Install a plug on the Solenoid hose C connection point.
Connect a vacuum pump to the Solenoid hose A connection point.
Attempt to apply 20 inches of vacuum to the Solenoid hose A connection point.
NOTE: Vacuum should escape through the Solenoid hose B connection
point.
Does vacuum escape through the Solenoid hose B connection point?
All
Yes
→ Go To 8
No
→ Replace the appropriate Solenoid.
8
Turn the ignition off.
Disconnect the hoses from the appropriate Solenoid.
Install a plug on Solenoid hose C connection point.
Connect a vacuum pump to the Solenoid hose B connection point.
NOTE: For the result of this test to be accurate the solenoid must be turned
on. Apply 12 volts and Ground to the appropriate solenoid terminals to turn
the solenoid on.
With vacuum pump apply 20 inches of vacuum to the Solenoid hose B connection
point.
NOTE: Vacuum reading should not drop below 10 inches within 5 seconds.
Does vacuum read above 10 inches for at least 5 seconds?
All
Yes
→ Go To 9
No
→ Replace the appropriate Solenoid.
9
Turn the ignition off.
Disconnect the hoses from the appropriate Solenoid.
Install a plug on the Solenoid hose A connection point.
Connect a vacuum pump to the Solenoid hose B connection point.
NOTE: For the result of this test to be accurate the solenoid must be turned
on. Apply 12 volts and Ground to the appropriate solenoid terminals to turn
the solenoid on.
Attempt to apply 20 inches of vacuum to the Solenoid hose B connection point.
NOTE: Vacuum should escape through the Solenoid hose C connection
point.
Does vacuum escape through the Solenoid hose C connection point?
All
Yes
→ Go To 10
No
→ Replace the appropriate Solenoid.
117
DRIVEABILITY - NGC
P0234-OVERBOOST PERFORMANCE —
Continued