Fan Air Solenoid Pin-Point Diagnostics - Navistar International DT 466 Diagnostic/Troubleshooting Manual

404 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS

Fan Air Solenoid Pin-Point Diagnostics

Voltage Checks at Fan Solenoid Connector (Disconnect solenoid. Turn the ignition switch to ON.)
Test Point
KOEO
A to gnd
B to gnd
Output State Test - Voltage Check at Fan Solenoid Connector (Disconnect solenoid. Turn the ignition
switch to ON. 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
Output State Test - Low
B+ to Pin B
Output State Test - High
B+ to Pin B
Output State Test - Voltage Checks at ECM (Disconnect X3 and X4 from ECM. Connect breakout box
X3 and X4 to ECM and wiring harness. Turn the ignition switch to ON. 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.)
Output State Test - Low
X3–3 to X4–14
Output State Test - High
X3–3 to X4–14
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Spec
B+ ± 0.5 V
0 V to 0.25 V
Spec
B+ ± 0.5 V
0 V to 0.25 V
B+ ± 0.5 V
0 V to 0.25 V
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
Comment
If < B+, check for open circuit. Do Harness Resistance
Checks.
If > 0.25 V, check ECM programming or open circuit.
Comment
If < B+, check ECM programming and check for open
circuit.
If > 0.25 V, check ECM programming and check for
short to voltage source.
If < B+, verify that ECM is programmed correctly. If
ECM is programmed correctly, replace ECM.
If > 0.25 V, verify that ECM is programmed correctly.
If ECM is programmed correctly, replace ECM.