Series 40E Troubleshooting – Section 11.13 Boost Pressure

Figure 1. Diagnostic Form

Follow this procedure to diagnose boost pressure. For a reproduction of the applicable portion of the diagnostic form, see Figure
“Diagnostic Form”

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Section 11.13.1
Purpose

The purpose of this test is to determine if the engine can develop sufficient boost pressure to obtain specific power.‪

Section 11.13.2
Test Procedure

This test should be performed at full load in conjunction with the Fuel Pressure Full Load and the ICP Pressure tests. Refer to “11.11 Fuel Pressure Full Load”

. Refer to “11.12 Icp Pressure”

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Note: Turn off all accessories and turn off the ignition before connecting the EST to the ATA connector.

1. Connect the EST to the ATA connector.
2. Turn the ignition switch to ON.
3. Access the data list and press the ↓ key until BOOST PSI is displayed on the screen. See Figure
   “Diagnostic For”.
   

   Figure 2. Diagnostic For

4. Drive vehicle on the road until the engine reaches operating temperature. Find an open section of the road and select a suitable gear. Depress the accelerator pedal (full depression) to the floor and accelerate to rated speed and 100% load.Note: Driving the vehicle uphill or fully loaded will facilitate efforts of reaching the proper engine loading at the rated engine speed.
5. Record intake manifold boost at full load rated engine speed.

Section 11.13.3
Alternate Test Procedure

This is the alternate procedure to test for boost pressure.‪

1. Remove the plug from the boost pipe. Install adaptor fitting and connect a line. See Figure
   “Boost Pressure Tap Location”. If no plug is provided on the boost pipe, remove the MAP (Manifold Absolute Pressure) sensor at the intake manifold/valve cover. Install a tee-fitting and install the MAP sensor again; install the test line to the fitting.Note: The MAP sensor must be connected during the boost pressure test.
   

   1. Tap Location‪

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   Figure 3. Boost Pressure Tap Location

2. Route the line ensuring it is not crimped or in contact with a hot engine surface inside the cab of the vehicle.
3. Temporarily install the Engine Field Test Kit, J 39257
   , in the cab of the vehicle (if applicable). Connect the line routed from the boost pipe or tee at the MAP sensor to the appropriate pressure gage.
4. Drive vehicle on the road until the engine reaches operating temperature. Find an open section of the road and select a suitable gear. Depress the accelerator pedal (full depression) to the floor and accelerate to rated speed and 100% load.Note: Driving the vehicle uphill or fully loaded will facilitate efforts of reaching the proper engine loading at the rated engine speed.
5. Record intake manifold boost at full load rated engine speed.

Note: If boost pressure is within specifications, the engine is functioning properly. There may be chassis or application concerns.

Section 11.13.4
Possible Causes

Possible causes for boost pressure problems are:‪

• Restricted intake or exhaust
• Low fuel pressure
• Low injection control pressure
• Control system faults
• Defective injectors
• Defective turbocharger
• Base engine failure

Section 11.13.5
Tools Required

Pro-Link 9000, J 38500–100
, or Engine Field Test Kit J 39257
, and a Tee-fitting.‪