7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS 465
ICP Pin-Point Diagnostics (ECM to valve cover
gasket connector)
Figure 467 ICP circuit diagram with VC Gasket Breakout Harness
Connector Voltage C hecks to Ground (Disconnect engine harness from valve cover gasket connector and
connect VC Gasket Breakout Harness to engine harness only. Turn the ignition switch to ON.)
Test Point
Spec Comment
Atognd 0to0.25V
If > 0.25 V, sig nal circ uit is sho rted to V
REF
or B+.
Btognd 5V±0.5V
If voltage is not to spec, V
REF
is shorted to ground, shorted to B+, or open.
Ctognd
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+.
Connector Resistance Checks to ECM Chassis Ground (Turn the ignition switch to OFF. Disconnect
harness from valve cover gasket connector. Connect VC Gasket Breakout Harness to engine harness only.
Disconnect chassis connector 9260
1
.)
AtoPinA
(9260)
>1kΩ If < 1 k Ω, check for short to ground within wiring harness.
BtoPinA
(9260)
>500Ω If < 500 Ω, check for short to ground within wiring harness.
CtoPinA
(9260)
<5Ω If > 5 Ω, check for open circuit.
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.)
A to gnd cable
>1kΩ If < 1 kΩ, check for short to ground.
B to gnd cable
>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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