Ect Pin-Point Diagnostics - Navistar International DT 466 Diagnostic/Troubleshooting Manual

396 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS

ECT 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
2 to gnd 4.6 V to 5.0 V
1 to gnd 0 V to 0.25 V
Connector Resistance Checks to ECM Chassis Ground (Turn the ignition switch to OFF. Disconnect
harness from sensor. Connect breakout harness to engine harness only. Disconnect chassis connector
1
9260 .)
1 to Pin A (9260) < 5 Ω
2 to Pin A (9260) > 1 kΩ
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
1
connector 9260 . Disconnect negative battery cable. Disconnect harness from sensor. Connect breakout
harness to engine harness only. Use disconnected negative battery cable for ground test point.)
1 to gnd cable > 500 Ω
2 to gnd cable
> 1 kΩ
Harness Resistance Checks (Connect breakout box to engine harness only. Disconnect harness from
sensor. Connect breakout harness to engine harness only.)
X1–6 to 1 < 5 Ω
X1–8 to 2 < 5 Ω
1
Connector 9260 is a 2-wire 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 complete chassis side ECM and IDM ground
circuit information.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Comment
Pull up voltage, if no voltage or low, circuit is open, has high
resistance, or short to ground
Voltage > 0.25 V, wire shorted to V
If > 5 Ω, check for open ground circuit.
If < 1 kΩ, check for shorted signal to ground within wiring harness.
If < 500 Ω, check for short to ground.
If < 1 kΩ, check for signal short to ground.
If > 5 Ω, check for open ground wire
If > 5 Ω, check for open signal wire
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
or B+.
REF