*CHECKING THE BOOST PRESSURE SYSTEM
For a complete wiring diagram Refer to Section 8W
| Possible Causes |
| TURBOCHARGER ASSEMBLY |
| BOOST PRESSURE ACTUATOR SUPPLY HOSE |
| BOOST PRESSURE ACTUATOR |
| INTAKE OR EXHAUST SYSTEM PROBLEM |
1. CHECKING THE BOOST PRESSURE ACTUATOR OPERATION
Turn the ignition off.
Disconnect the Valve Block vacuum hose connector.
Connect a vacuum pump to the Boost Pressure Actuator supply port of the disconnected Valve Block vacuum hose connector. This port is attached to the Gray colored vacuum tube at the Valve Block vacuum hose connector.
While standing at the right front of the vehicle (front of engine side), observe the position of the Boost Pressure Actuator armature.
NOTE: The armature should be in the 10 o'clock position with the ignition off (armature in rest position).
While observing the armature, apply 20 inches of vacuum.
NOTE: The armature should move counterclockwise from the 10 o'clock position to the 9 o'clock position.
Is the Boost Pressure Actuator operating from the 10 o'clock to the 9 o'clock position when 20 inches of vacuum is applied?
Yes
- Go to 4
No
- Go To 2
2. CHECKING THE BOOST PRESSURE ACTUATOR SUPPLY HOSE
Check the Gray colored vacuum hose between the Valve Block hose connector and the Boost Pressure Actuator for leaks, kinks, debris or other restrictions.
NOTE: Problems with this hose will cause incorrect vacuum to the Boost Pressure Actuator resulting in driveability problems.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go to 3
3. CHECK FOR BOOST PRESSURE ACTUATOR LINKAGE PROBLEM
Disconnect the linkage from the Boost Pressure Actuator and inspect the linkage for foreign debris, binding or damage that could cause restricted movement.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Refer to the Service Information and replace the Boost Pressure Actuator or Turbocharger Assembly as necessary.
4. CHECK FOR INTAKE AND EXHAUST SYSTEM RESTRICTIONS
Inspect the exhaust system for damaged components that could cause exhaust flow blockage.
Inspect all air intake, crankcase vent and turbocharger related hoses/tubes and connections for damage, air leaks or blockage.
Inspect the air filter for excessive dirt, soiling or other problems that may cause restricted air flow.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go to 5
5. CHECKING THE BOOST PRESSURE ACTUATOR OPERATION
NOTE: The engine temperature must be above 160°F for this test to be valid.
Turn the ignition off.
Disconnect the Valve Block vacuum hose connector.
Connect a vacuum pump to the Boost Pressure Actuator supply port of the disconnected Valve Block vacuum hose connector. This port is attached to the Gray colored vacuum tube at the valve Block vacuum hose connector.
Set the engine speed to 1,500 rpm.
With the scan tool, observe and note the Boost Pressure hpa reading.
While observing the scan tool, apply 15 inches of vacuum.
NOTE: The Boost Pressure hpa reading should increase more than 100 hpa as well as an audible engine tone change when 15 inches of vacuum is applied.
Does the Boost Pressure hpa reading increase more than 100 hpa when 15 inches of vacuum is applied?
Yes
- Test complete.
No
- Refer to the Service Information and replace the Turbocharger assembly.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)