Navistar International DT 466 Diagnostic/Troubleshooting Manual page 354

350 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
WARNING: To avoid serious personal injury, possible death, or damage to the engine or vehicle,
always disconnect main negative battery cable first. Always connect the main negative battery cable
last.
Voltage Check at Diagnostic Connector (Check at diagnostic connector with key-on engine-off.)
Test Point Spec
B to A B+
C to A 1 V to 4 V
D to A 1 V to 4 V
Resistance Check at Diagnostic Connector (Turn the ignition switch to OFF. Check at diagnostic
connector with negative battery cable disconnected.)
C to A > 1 MΩ
D to A > 1 MΩ
C to D 60 Ω
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Signal Comment
Power Should be B+ power at B all times. If no power, check
ground and power circuits. See truck Chassis Electrical
Circuit Diagram Manual.
Digital The sum of C to A and D to A equals 4 V to 5 V.
signal
Digital
The sum of C to A and D to A equals 4 V to 5 V.
signal
CAN+ If < 1 MΩ, a short between CAN+ and ground exists.
Disconnect ECM X3 and check again. If short is no longer
present, replace ECM. If short exists, harness or other node
component is inoperative.
CAN – If < 1 MΩ, a short between CAN – and ground exists.
Disconnect ECM X3 and check again. If short is no longer
present, replace ECM. If short still exists, harness or other
node component inoperative.
CAN The datalink has two terminating resistors in parallel of 120
Ω each. If > 70 Ω, check for missing terminating resister
or open in the CAN+ or CAN – wires. If < 50 Ω, check for
extra terminating resistor. If < 5 Ω, check for short between
CAN+ and CAN –.
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.