Navistar International DT 466 Diagnostic/Troubleshooting Manual page 343

7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
NOTE: Complete all pin-point diagnostics (ECM to valve cover gasket connector) before removing
valve cover for under-valve-cover diagnostics.
• 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 at Valve Cover Gasket Connector (Disconnect engine harness from
valve cover gasket. Inspect for bent pins or corrosion. Connect VC Gasket Breakout Harness to engine
harness and valve cover gasket. Turn the ignition switch to ON.)
Test Point
C to A
C to gnd
A to gnd
Output State Test - Signal Check at Valve Cover Gasket Connector (Disconnect engine harness from
valve cover gasket. Connect VC Gasket Breakout Harness to engine harness and valve cover gasket. Run
the Output State Tests. For help, see "Diagnostic Software Operation" in Section 3 (page 68) for procedure
to run the Low and High Output State Tests.)
Test State/Point
KOEO
C to A
Output State Test - Low DMM set to V - DC
C to A
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Spec
0 V to 0.25 V
0 V to 0.25 V
0 V to 0.25 V
Setting/Spec
DMM set to V - DC
0 V to 0.25 V
0 V to 0.25 V
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
Comment
If > 0.25 V, continue with next test point, C to ground.
If > 0.25 V, control wire is shorted to V
open ground, open control circuit, or open solenoid
exists.
If > 0.25 V, ground wire is shorted to V
Comment
If > 0.25 V, disconnect VC Gasket Breakout Harness
from gasket. Connect 500 Ohm Resistor Harness
between C and A and retest.
• If > 0.25 V, run the Low and High Output State Test.
• If < 0.25 V, the concern is the valve cover gasket,
UVC wiring, or brake shut-off valve.
Toggling between the Low and High Output State Tests
can be done during this procedure.
If > 0.25 V, disconnect VC Gasket Breakout Harness
from gasket. Connect 500 Ohm Resistor Harness
between C and A and retest Output State Test - Low.
• If > 0.25 V the concern is the engine harness or
ECM, check for a short to B+ or V
• If < 0.25 V, the concern is the valve cover gasket,
UVC wiring, or Brake Shut-off Valve.
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or B+, or an
REF
or B+.
REF
.
REF