7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS 505
1
Connector 9260 is a 2-wire connector us ually located in the battery box. Pin A is the chassis ground connection for the
ECM and IDM. See truck Chassis Electrical Circuit Diagram Manual for comp lete chassis s ide ECM and IDM g r ou nd
circuit information.
MAP Pin-Point Diagnostics
Connector Voltage Checks to Ground (Disconnect harness fro m sens
or. Inspect for bent pins or corrosion.
Connect breakout harness to engine harness only. Turn the igniti
on 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 s horted to gr
ound, shorted to
B+, or open.
3 to gnd 0 V to 0.25 V
If > 0.25 V, sig na l circuit is shorte d 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
.)
1toPinA(9260) <5Ω 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.
3toPinA(9260) >1kΩ 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 g ro
und.
2togndcable
>500Ω If < 500 Ω, check for short to ground.
3togndcable
>1kΩ If < 1 kΩ , chec k for short to ground.
Harness Resistance Check
s (Connect breakout box to engine harness [X1 and X2 only] and breakout
harness to engine harness
only.)
X1–6 to 1
<5Ω If > 5 Ω, check for open ground w ire.
X1–14to2
<5Ω If > 5 Ω, check for open V
REF
wire.
X2–3 to 3
<5Ω If > 5 Ω, check for open
signal wire.
1
Connector 9260 is a 2-w
ire connector usually located in the battery box. Pin A is the chassis ground connection for the
ECM and IDM. See truck Chassis Electrical Circuit Diagram Manual for comp lete chassis s ide ECM and IDM g r ou nd
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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