7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS 431
EOP Pin-Point Diagnostics
Figure 447 EOP circuit diagram
Connector Voltage Checks to Ground (Disconnect harness from sensor. Inspect for bent pins or corrosion.
Connect breakout harness to engine harness only. Turn the ignition switch to ON.)
Test Point
Spec Comment
1 to gnd 0 V to 0.25
V
Signal ground (no voltage expected). If > 0.25 V, check ground circuit for
open or high resistance and check signal ground for short to V
REF
or B+.
2tognd 5V±0.5V
If voltage is not to spec, V
REF
circuit is shorted to ground, shorted to B+,
or open.
3 to gnd 0 V to 0.25
V
If > 0.25 V, signal circuit is s ho rted to V
REF
or B+.
Connector Resistance Checks to ECM Chassis Ground (Turn the ignition switch to OFF. Connect
breakout harness to engine harness only. Disconnect chassis connector 9260
1
.)
1 to Pin A (9260) < 5 Ω If > 5 Ω, check for open circuit.
2 to Pin A (9260) > 500 Ω If < 500 Ω, check for short to ground within wiring harness.
3 to Pin A (9260) > 1 kΩ If < 1 kΩ, check for short to ground within wiring harness.
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.
Connector Resistance Checks to Chassis Ground (Turn the ignition switch to OFF. Disconnect chassis
connector 9260
1
. Disconnect negative battery cable. Disconnect harness from sensor. Use disconnected
negative battery cable for ground test point.)
1togndcable
>500Ω If < 500 Ω, check for short to ground.
2togndcable
>500Ω If < 500 Ω, check for short to ground.
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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