15. Boost Pressure Test

15. BOOST PRESSURE TEST

Purpose:
The purpose of this test is to determine if the engine can develop sufficient boost.

Boost Pressure Test
- Carefully inspect the CAC tubes/connections, turbocharger connections, MAP and IAT2 sensors for signs of damage or leaks.
- Carry out the boost pressure test at 3,300 RPM minimum.
- Monitor the MGP and RPM PIDS with the scan tool.
- Road test - select the appropriate gear to obtain desired engine speed and full load condition.







Recommended Procedure:

NOTE: If the test fails low, inspect the turbocharger blades for damage. GO to Pinpoint Test KA to check the turbocharger operation. Test KA: Turbocharger System Performance

Boost pressure levels out after 3,300 RPM. This is best accomplished either climbing a hill or with the vehicle fully loaded.
- Connect the scan tool.
- Ignition ON, engine running.
- Access and monitor the MGP and RPM PIDS.
- After the engine is up to operating temperature, find an open section of road and select the best gear to achieve a 3,300 RPM acceleration.
- With the accelerator at WOT, record the highest boost pressure reading while accelerating through the 2,500-3,300 RPM range.

Possible Causes:
- Leak around MAP sensor
- Leak around IAT2 sensor
- Leaking intake, hoses or fittings
- Turbocharger
- Base engine
- CAC tubes leaking
- CAC
- EGR sticking

Tools Required
Scan tool