Navistar International DT 466 Diagnostic/Troubleshooting Manual page 317

7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
Harness Resistance Checks – Diagnostic Connector to ECM (Turn the ignition switch to OFF. Connect
breakout box [X4 only] to engine harness only.)
F to ECM X4–20
G to ECM X4–21
B to fuse
A to gnd
Harness Resistance Checks – Diagnostic Connector to IDM (Turn the ignition switch to OFF.)
F to IDM X3–28
G to IDM X3–29
ATA Diagnostic Trouble Codes
231 ATA data communication link error – ATA wiring or connector
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
< 5 Ω ATA +
< 5 Ω ATA –
< 5 Ω Power
< 5 Ω gnd
< 5 Ω ATA +
< 5 Ω ATA –
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
Resistance from ECM chassis connector to
EST connector.
Resistance from ECM chassis connector to
EST connector.
Resistance from EST connector to power fuse.
See truck Chassis Electrical Circuit Diagram
Manual for circuit numbers, connector and fuse
locations.
If > 5 Ω, check for an open circuit. Open circuit
will prevent EST power up.
Resistance from IDM connector to EST
connector.
Resistance from IDM connector to EST
connector.
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