7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS 535
X1–18toX1–6 0Vto0.25V
If > 0.25 V, disconnect engine harness from breakout box
harness and retest.
• If < 0.25 V, diagnose engine wiring harness. Do
Harness Resistance Check – VGT Actuator to ECM
(page 538).
• If > 0.25 V, with breakout box only connected to
ECM, replace ECM.
Output State Test - High DMM set to V - DC Listen and observe to verify if crank lever of VGT
actuator moves. Toggling between the Low and High
Output State Tests can be done during this test.
X1–18 to X1–6 B+ ± 0.5 V
If value is not in specification, disconnect engine harness
from breakout box harness and retest.
• If equal to B+, diagnose engine w iring harness. Do
Harness Resistance Check – VGT Actuator to ECM
(page 538).
• If < B+ with breakout box only connected to ECM ,
replace ECM.
1
Values are c alibration depende nt. See “DT 466 Performance Speci fi cations” – Appendix A (page 595) or “DT 570 and
HT 570 P erforman ce Specifications – Appendix B (page 619).
2
Use the EST with MasterDiagnostics® softwa
re to view VGT duty cycle with key-on engine-off. When using the Fluke
88 DMM, measurement is typically within 2% of what MasterDiagnostics® reads.
EGES-270-1
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
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