158 5 HARD START AND NO START DIAGNOSTICS
• If the EST shows 0 rpm during engine
cranking, the ECM may not be receiving
a signal from the Crankshaft Position (CKP)
sensor or Camshaft Position (CMP) sensor.
The ECM will not send the fueling command
to the IDM without a correct CKP or CMP
signal. See CKP sensor (page 351) and
CMP sensor (page 355) in Section 7.
• If the EST indicates low or no injectio n control
pressure, do Test 14 – “Low ICP System
Pressure” (page 186).
If the ICP sensor is biased high, see “ICP
Sensor” in Section 7 (page 457).
• If oil pressure is low, the ICP system may not
be receiving enough oil.
• IfEGRvalveisopenatstart-upitcandisrupt
the air fuel mixture enough to inhibit engine
operation.
•BCPvaluesmayfluctuate as much as 345
kPa (50 psi). Electromagnetic interference
(EMI) or ground shift can cause an
insignificant voltage shift that does not
indicate a problem. If above 7 MPa (1000
psi), brake actuation may occur. If over 345
kPa (50 psi), ICP operation may be inhibited
for fuel injectors.
Possible Causes
Low battery voltage
• Failed batteries
• High-resistance at battery cable connections or in
wiring to the ECM
• Failed ECM m ain power relay
• Blown inline fuse (in battery box) that supplies
voltage to the ECM
• Blown fuse in power distribution box
Low cranking rpm
• Electrical sys te m malfunctions, in correct oil,
or long oil change intervals in c old ambient
temperatures
• No rpm indication on the EST while cranking
the engine: Failed CKP sensor, CMP sensor, or
circuit to the ECM. Check DTCs after cranking
engine for 20 seconds.
Low Injection Control Pressure
• A leak in t he high-pressure oil system
• Failed ICP sensor
• Low oil level in the high-pressure oil reservoir
• Failed I PR valve or e lectronic controls for the
regulator
• Failed high-pressure oil pump or pump drive
Low oil pressure
• Failed oil pressure regulator relief valve
• Failed gerotor oil pump or front cover
• Failedpickuptubeorgasket
• Internal lube oil pressure leak
EGR valve
• Stuck or inoperative valve
BCP
• Inoperative brake shut-off valve
• Failed BCP sensor
• Failed BCP sensor wiring
• Porosity or sand hole in high-pressure oil rail
(injector oil gallery to brake o il gallery)
EGES-270-1
Read all safety instructions in the "Safety Information" section of this manual before doing any proced ures.
Follow all warnings, cautions, and notes.
©August 2008 Navistar, Inc.
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