7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS 305
4. If code is active, do step 6 and 7 to check circuit
for the APS sensor using the following table.
• Circuit C he cks for APS Sens or
5. If code is inactive, wiggle connectors and wires
at all suspected problem locations. If circuit
continuity is inte rrup te d, the EST will d isp lay
DTCs related to the condition.
6. Disconnect chassis harness from APS sensor.
NOTE: Inspect connectors for damaged pins,
corrosion, or loose pins. Repair if necessary.
7. Connect APS Sensor Breakout Harness to
chassis harness only.
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 APS Sensor (Use EST, DMM, breakout harness, and 500 Ohm Resistor Harness.)
Test Condition Spec Checks
Sensor disconnected using
EST
0V
If voltage > 0.147 V, check signal circuit for short to V
REF
or B+.
Measure voltage from Pin C
(Blue) to ground using DMM
5V±0.5V
If voltage > 5.5 V, check V
REF
for short to B+. If voltage is <
4.5 V, check V
REF
for open or short to ground.
500 Ohm Resistor Harness
connected between Pin A
(Green) and Pin C (Blue) of
breakout harness using.
5V
If voltage < 4.55 V, check signal circ
uit for open or short to
ground.
— Disconnect connector 9260
1
. Measur
e resistance from
Pin C to Pin A of connector 9260 (spec
>1kΩ) to check
for short to ground within wiring ha
rness.
— D isconnect negative battery cab
le. Measure resistance
from Pin C to ground cable to chec
k for short to ground.
— U se a breakout box to measure from
PinAtoPinX4–18
(spec < 5 Ω) to check for open in th
e harness.
Resistance from Pin B (Black)
of breakout harness to ECM
chassis ground P in A of
connector 9260 using DMM.
<5Ω If resistance is > 5 Ω, check for open or high resistance
between ECM and sensor connector. Use a breakout box
and m easure resistance from between Pin B and Pin X4–24
(spec < 5 Ω).
Connect chassis harness to sensor and cycle key. Use the EST to clear DTCs. If an active code
remains after checking test conditions, inspect pedal assembly for excessive wear. If pedal
assembly is in tact, replace the APS/IVS sensor.
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.
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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