Navistar International DT 466 Diagnostic/Troubleshooting Manual page 390

386 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.
Harness Resistance Checks – Main Power Relay to Battery (Turn the ignition switch to OFF. Disconnect
negative battery cable. Disconnect harness from sensor. Inspect for bent pins or corrosion. Connect
relay breakout harness.)
30 (ECM relay) to B+ cable
86 (ECM relay) to B+ cable
Harness Resistance Checks – ECM to ECM Chassis Ground (Turn the ignition switch to OFF. Disconnect
chassis connector 9260
harness only.)
X3–6 to Pin A (9260)
X3–7 to Pin A (9260)
X3–3 to Pin A (9260)
X3–5 to Pin A (9260)
X4–1 to Pin A (9260)
X4–2 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 Checks – ECM to Chassis Ground (Turn the ignition switch to OFF. Disconnect
chassis connector 9260
disconnected negative battery cable for ground test point.)
X3–6 to gnd cable
X3–7 to gnd cable
X3–3 to gnd cable
X3–5 to gnd cable
X4–1 to gnd cable
X4–2 to gnd cable
Harness Resistance Checks – ECM to Ignition Power Relay (Turn the ignition switch to OFF. Inspect for
bent pins or corrosion. Connect relay breakout harness and breakout box [X3 and X4] to chassis harness
only.)
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
< 5 Ω If > 5 Ω, check connections for open between relay and positive
battery cable. Check fuses. See truck Chassis Electrical Circuit
Diagram Manual for relay and fuse locations.
< 5 Ω If > 5 Ω, check connections for open between relay and positive
battery cable. Check fuse. See truck Chassis Electrical Circuit
Diagram Manual for relay and fuse locations.
1
. Inspect for bent pins or corrosion. Connect breakout box [X3 and X4] to chassis
< 5 Ω If > 5 Ω, check connections to battery ground. See truck Chassis
Electrical Circuit Diagram Manual for relay and fuse locations.
< 5 Ω If > 5 Ω, check connections to battery ground. See truck Chassis
Electrical Circuit Diagram Manual for relay and fuse locations.
> 1 kΩ If < 1 kΩ, check for short to ground within wiring harness.
> 1 kΩ If < 1 kΩ, check for short to ground within wiring harness.
> 1 kΩ If < 1 kΩ, check for short to ground within wiring harness.
> 1 kΩ If < 1 kΩ, check for short to ground within wiring harness.
1
. Disconnect negative battery cable. Disconnect harness from sensor. Use
> 500 Ω If < 500 Ω, check for short to ground.
> 500 Ω If < 500 Ω, check for short to ground.
> 500 Ω If < 500 Ω, check for short to ground.
> 1 kΩ If < 1 kΩ, check for short to ground.
> 1 kΩ If < 1 kΩ, check for short to ground.
> 1 kΩ If < 1 kΩ, check for short to ground.
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
EGES-270-1