346 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
NOTE: Complete all pin-point diagnostics (ECM to valve cover gasket connector) bef
ore removing
valve cover for under-valve-cover diagnostics.
• Turn the ignition switch to OFF before disconnecting engine wiring harne
ss connectors from components.
• See truck Chassis Electrical Circuit Diagram Manual for c ircu it numbers
, connector and fuse locations.
Harness Resistance Check – UVC Connector to ECM Chassis Ground (Turn the ignition switch to OFF.
Disconnect chassis connector 9260
1
.)
Test Point
Spec Comment
1 to Pin A (9260) < 5 Ω If > 5 Ω, check for an open circuit.
2 to Pin A (9260) > 1 kΩ If < 1 kΩ, check for short to ground within wiring harness.
Harness Resistance Check – UVC Connector to Chassis Ground (Turn the ignition switch to OFF.
Disconnect chassis connector 9260
1
. Disconnect negative battery cable. Disconnect harness from valve.
Use disconnected negative battery cable f or ground test point.)
1togndcable
>500Ω If < 500 Ω, check for short to ground.
2togndcable
>1kΩ If < 1 kΩ, check for short to ground.
Harness Resistance Check – Valve Cover Gasket Connector to UVC Connector (Connect VC Gasket
Breakout Harness to valve cover gasket only.)
Ato1
<5Ω If > 5 Ω, check for open in actuator ground.
Cto2 <5Ω If > 5 Ω, check for open in control wire.
Solenoid Resistance C heck – Brake Shut-off Valve (Measure across terminals of solenoid.)
2to1
10 Ω ±2Ω If not to specification, replace brake s
hut-off valve.
1
Connector 9260 is a 2-wire connector usu
ally located in th e battery box. Pin A is the g r ound connection for the ECM
and IDM. See truck Chassis Electrical Circuit Diagram Manual for complete chassis side ECM and IDM groun d circuit
information.
EGES-270-1
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
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