Navistar International DT 466 Diagnostic/Troubleshooting Manual page 465

7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
ICP Operational Diagnostics
Figure 465 ICP circuit diagram with VC Gasket Breakout 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.
Circuit Checks for ICP – ECM to Valve Cover Connector (Use EST, DMM, 500 Ohm Resistor Harness,
and VC Gasket Breakout Harness connected to engine harness only.)
Test Condition
Harness disconnected from valve
cover gasket connector using
EST
Voltage from Pin B (Blue) of VC
Gasket Breakout Harness to
ground using DMM
500 Ohm Resistor Harness
connected between Pin A
(Green) and Pin B (Blue) of VC
Gasket Breakout Harness using
EST
Resistance from Pin C (Black) of
VC Gasket Breakout Harness to
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Spec Checks
0 V If voltage > 0.039 V, check ICP signal for short to V
or B+.
5 V ±0.5 V If voltage > 5.5 V, check V
< 4.5 V, check V
5 V If voltage < 4.9 V, check ICP signal for open or short to
ground.
— Disconnect connector 9260
from Pin A to Pin A of connector 9260 (spec > 1 kΩ)
to check for short to ground within wiring harness.
— Disconnect negative battery cable. Measure
resistance from Pin A (spec > 1 kΩ) to ground cable
to check for short to ground.
— Use a breakout box to measure resistance from
X1-20 to Pin A (spec < 5 Ω) to check for open circuit.
< 5 Ω If resistance is > 5 Ω, check for open or high resistance
between ECM and VC Gasket Breakout Harness
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
for short to B+. If voltage is
REF
for open or short to ground.
REF
1
. Measure resistance
461
REF