512 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
MAT Pin-Point Diagnostics
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
If > 0.25 V, s ignal wire is shorted to V
REF
or battery.
2tognd 4.6Vto5V
Pull up voltage. If no voltage, circuit has open or high resistance or
short to ground.
Connector Resistance Checks to ECM Chassis Ground (Turn
the ignition switch to OFF. Disconnect
harness from sensor. Connect breakout harness to engin
e 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) > 1 kΩ If < 1 kΩ, check for short to ground w ithin 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 Grou
nd (Turn the ignition switch to OFF. Disconnect chassis
connector 9260
1
. Disconnect negative batt
ery cable. Disconnect harness from sensor. Connect breakout
harness to engine harness only. Use dis
connected negative battery cable for ground test point.)
1togndcable
>500Ω If < 500 Ω, check for short to ground.
2togndcable
>1kΩ If < 1 kΩ, check f or short to ground.
Harness Resistanc e Checks (Connect
breakout box [X1 and X2 only] to engine harness. Connect
breakout harness to engine harness
only.)
X1–6 to 1
<5Ω If > 5 Ω, check for open ground wire.
X2–14to2
<5Ω If > 5 Ω, check for open sig nal wire.
1
Connector 9260 is a 2-wi r e connector usually lo c ated in the battery box. Pin A is the chassis ground connection for the
ECM and IDM. See truck Chassis Electrical Circuit Diagram Manual for complete chassis side ECM and IDM g round
circuit information.
Operational Voltage Checks for MAT Sensor with Breakout Harness (Check with breakout harness
connected to sensor and engine harness.)
Test Point Temp Resistance
Voltage @ Resistance
2 (Green) to 1
(Black)
0 °C ( 32 °F) 93.8 kΩ
4.36 V
2 (Green) to 1
(Black)
15 °C (59 °F) 4 7.6 kΩ
4.0 V
2 (Green) to 1
(Black)
40 °C (104 °F) 15.8 kΩ
2.98 V
2 (Green) to 1
(Black)
100 °C (212 °F) 2.3 kΩ
0.93 V
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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