Vgt Pin-Point Diagnostics - Navistar International DT 466 Diagnostic/Troubleshooting Manual

528 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS

VGT Pin-Point Diagnostics

Figure 500 VGT circuit diagram
NOTE: Turn the ignition switch to OFF before disconnecting engine wiring harness connectors from
components.
See truck Chassis Electrical Circuit Diagram Manual for circuit numbers, connector and fuse locations.
Actuator Control Voltage Check (Disconnect actuator harness from engine harness. Connect Turbo
Breakout Harness to engine and actuator harness. Turn the ignition switch to ON.)
Test Point
1 to 2
1 to chassis gnd
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Spec
B+ ± 0.5 V
B+ ± 0.5 V
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
Comment
If < B+, continue with next test point, 1 to chassis gnd.
If equal to B+, check test point 3 to gnd (KOEO).
If equal to B+, but 1 to 2 did not equal B+, check for
high resistance or open in ground circuit. Do Harness
Resistance Checks – ECM to ECM Chassis Ground
(page 537).
If < B+, disconnect the actuator harness from Turbo
Breakout Harness and retest.
• If < B+, do 12-pin Actuator Power Voltage Check
(page 532).
• If equal to B+, the concern is either high resistance
in wiring or the VGT actuator. Do Harness
Resistance Checks (page 537) to confirm integrity
of wiring. See truck Chassis Electrical Circuit
Diagram Manual.
If integrity of wiring is confirmed to be in good
condition, replace VGT actuator.