ICP System Function Test
• The Injection Control Pressure system must
be able to build a minimum of 500 psi for
the engine to start. During cranking, the
ECM must command the IPR valve
partially closed to create the pressure
required for starting. Test this function by
replacing the ECM signal with a direct
connection between the IPR and battery
power and ground.
• Disconnect the IPR from the engine
harness. Install the Actuator Breakout
Harness (ZTSE4484) to the IPR only. Use
jumper wires to provide power to one lead
and a ground to the other. Crank the
engine while measuring the injection
control pressure. If the engine starts or the
pressure now exceeds the minimum
cranking pressure, the ECM is not
controlling the IPR.
•
Caution:
Do not leave the IPR powered
for more than 120 seconds or the IPR may
be damaged.
IPR Function Test
• The IPR must function for the ICP system
to build sufficient pressure to start.
Remove the ICP sensor from the right
bank valve cover. Install the ICP System
Test Adapter (ZTSE4594) with an air
fitting in place of the sensor. Remove the
oil fill cap and attach shop air pressure to
the air fitting.
• Listen at the opening of the oil fill cap for
air leaking into the crankcase from the IPR.
Allow five minutes for the air to displace
the oil through the system (cold oil may
take longer). If there is a massive air leak in
the crankcase when the air is connected,
go to the Under Valve Cover Leak test. If
there is a faint leak, install the Actuator
Breakout Harness (ZTSE4484) to the IPR
only. Provide power to one breakout
harness lead and a ground to the other.
The faint air leak in the crankcase should
stop when power is applied. This verifies
the ECM signal can operate the IPR valve
internally. If the faint air leak stops when
the IPR is given power and ground,
perform the pump test.
DIAGNOSTIC TESTS
97
International
®
VT 275 V6 Engine
AAC
CTTU
UAATTO
OR
R
B
BR
REEAAK
KO
OU
UTT
H
HAAR
RN
NEES
SS
S
IIP
PR
R H
HEEAATT S
SH
HIIEELLD
D
S
SH
HO
OP
P AAIIR
R S
SU
UP
PP
PLLYY
S
SH
HO
OP
P AAIIR
R S
SU
UP
PP
PLLYY
IIC
CP
P TTEES
STT AAD
DAAP
PTTEER
R
IIC
CP
P TTEES
STT AAD
DAAP
PTTEER
R
R
RIIG
GH
HTT B
BAAN
NK
K VVAALLVVEE C
CO
OVVEER
R