Series 40E Troubleshooting – Section 10.9 Est — Injector Buzz Test

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Figure 1. Diagnostic Form

The following procedure will lead you through the Injector Buzz Test. For a reproduction of the applicable portion of the diagnostic form, see Figure
“Diagnostic Form”


Section 10.9.1

This test will determine if the injectors are functioning correctly electronically, by energizing each injector in a programmed sequence. The ECM will monitor this test and transmit fault codes if any injector(s) or electrical circuitry are not functioning properly.‪

Section 10.9.2
Test Procedure

Access Diagnostic codes menu in EST and clear all fault codes.‪

Note: Engine OFF standard test must be performed first in order to access the Injector Buzz Test. Press enter to begin the test.

After the Engine OFF standard tests have been completed, press the ↓ key to access the INJECTOR TEST. If the tool is not on a menu screen, i.e. displaying the fault codes, etc., press the FUNC key. This will access the ENGINE OFF TESTS menu. Press enter to begin the test. See Figure
“Engine OFF Tests Menu”


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Figure 2. Engine OFF Tests Menu

During this test, the injector solenoids will produce an audible clicking sound when actuated. It is possible to detect a malfunctioning injector by listening for the absence of the solenoid clicking sound.‪

Note: If fault codes were cleared before the Injector Buzz Test, fault codes displayed will be actual faults found during the test. If codes were not cleared before testing, access INACTIVE FAULT CODES from the EST menu to retrieve faults found during this test.

At the completion of the injector test, any faults that have been detected will be displayed. Additional faults can be accessed by pressing the ↓ key.‪

Record any faults found and refer to “12.1 General Instructions”

. ‪

Section 10.9.3
Possible Causes

Possible causes for the hard start or no start diagnosis include:‪

  • Bad wiring harness connection at the injector solenoid
  • Open or shorted engine wiring harness to the injectors
  • Defective injector solenoids
  • Defective ECM

Section 10.9.4
Tools Required

Pro-Link 9000, J 38500–100


Section 10.9.5
Supplemental Diagnostics

If fault codes are set, refer to the Electronic Diagnostic Form; refer to “10.1 Introduction”

, and fault code diagnostics.‪

Series 40E Troubleshooting Manual – 6SE241
Generated on 10-13-2008