Navistar International DT 466 Diagnostic/Troubleshooting Manual page 454

450 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
Harness Resistance Check – Relay to ECM Chassis Ground (Turn the ignition switch to OFF. Disconnect
chassis connector 9260
Relay 1: A to Pin A (9260)
Relay 1: B to Pin A (9260)
Relay 2: A to Pin A (9260)
Relay 2: B to Pin A (9260)
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.
Harness Resistance Check – Relay to Chassis Ground (Turn the ignition switch to OFF. Disconnect
chassis connector 9260
disconnected negative battery cable for ground test point.)
Relay 1: A to gnd cable
Relay 1: B to gnd cable
Relay 2: A to gnd cable
Relay 2: B to gnd cable
Harness Resistance Check – Relay to ECM (Turn the ignition switch to OFF. Connect breakout box
[X1 only] to engine harness.)
Relay 1: Pin A to X1–17
Relay 2: Pin A to X1–17
Harness Resistance Check – Relay to 12–pin Connector (Turn the ignition switch to OFF. Connect
12–pin breakout harness to engine harness only.)
Relay 1: Pin B to Pin 4 (12-pin) < 5 Ω
Relay 2: Pin B to Pin 4 (12-pin) < 5 Ω
IAH Diagnostic Trouble Codes (DTCs)
DTC 251 = OCC self-test failed
1
Connector 9260 is a 2-wire connector usually located in the battery box. Pin A is the chassis ground connection for
the ECM and IDM. Refer to truck Chassis Electrical Circuit Diagram Manual for complete chassis side ECM and IDM
ground circuit information.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
1
. Disconnect control wiring from relay.)
> 1 kΩ
< 5 Ω
> 1 kΩ
< 5 Ω
1
. Disconnect negative battery cable. Disconnect control wiring from relay. Use
> 1 kΩ
> 1 kΩ
> 1 kΩ
> 1 kΩ
< 5 Ω
< 5 Ω
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
If < 1 kΩ, check for short to ground within wiring harness.
If > 5 Ω, check for open circuit. Specification is based
on 4300 chassis. For other applications, see Chassis
Electrical Circuit Diagram Manual for complete chassis
ground circuit information.
If < 1 kΩ, check for short to ground within wiring harness.
If > 5 Ω, check for open circuit. Specification is based
on 4300 chassis. For other applications, see Chassis
Electrical Circuit Diagram Manual for complete chassis
ground circuit information.
If < 1 kΩ, check for short to ground.
If < 1 kΩ, check for short to ground. Specification is based
on 4300 chassis. For other applications, see Chassis
Electrical Circuit Diagram Manual for complete chassis
ground circuit information.
If < 1 kΩ, check for short to ground.
If < 1 kΩ, check for short to ground. Specification is based
on 4300 chassis. For other applications, see Chassis
Electrical Circuit Diagram Manual for complete chassis
ground circuit information.
If > 5 Ω, check for open in circuit.
If > 5 Ω, check for open in circuit.
If > 5 Ω, check for open in control wire.
If > 5 Ω, check for open in control wire.
EGES-270-1