
38 RENR5622
Troubleshooting Section
Table 17
Event Code
Description
Conditions wh
ich Generate this Code
System Respon
se
E093 Boost Pressure Below Normal The actual boost pressure is below the
desired boost pressure.
The code is logged and the code is
active.
Pr
obable Causes
•
Air inlet restrictions
•
Fuel supply
•
In
jector solenoid
•
Wastegate
•
Engine speed/timing signal
•
Act
ive engine derate
•
Intermittent sensor problem
Air Inlet Restrictions
Che
ck for restrictions in the air inlet system. Refer
to Systems Operation/Testing and Adjusting for
information on inspecting the air inlet system.
Fuel Supply
1. Ch
eck fuel lines for the following problems:
restrictions, collapse, and pinched line. Repair the
lines and/or replace the lines.
a. Check the fuel tank for foreign objects which
may block the fuel supply. Check for air in the
lo
w pressure fuel supply system after you have
performed the following procedures:
•
R
eplace the filters.
•
Work on the low pressure fuel supply circuit
•
Replace the fuel injectors.
b
.
P
urge air from the fuel system with the priming
pump and by cranking the engine in 30 second
cycles. After you crank the engine, stop for two
m
inutes. This will allow the starting motor to
cool. Loosen the vent plug at the fuel return.
The plug is located on the rear upper left side
o
f the engine block. Prime the engine again if
air in fuel continues. A sight glass in the low
pressure supply line is helpful in diagnosing
air in the fuel.
c. Ch
eck fuel quality. In temperatures below 0 °C
(32 °F), check for solidified fuel (wax). Refer
to the Operation and Maintenance Manual for
in
formation on improving the characteristics of
the fuel during cold weather operation. Check
the fuel pressure while the engine is cranking.
C
heck the fuel pressure at the filter. Refer to
the Specifications manual for correct pressure
values. If the pressure is low, check for plugged
f
uel filters. If the fuel pressure is still low, check
the following items: fuel transfer pump, fuel
transfer pump coupling, and fuel pressure
regulating valve. Check for a problem with the
combustion system.
Injector Solenoid
Check for active diagnostic codes for the injector
solenoids. Check for logged diagnostic codes for
the injector solenoids. Perform the Injector Solenoid
Test. Observe that the injector solenoids are being
energized on Caterpillar Electronic Technician
(ET). Perform the Cylinder Cutout Test. Locate the
misfiring cylinder. Refer to the diagnostic functional
test Troubleshooting, “Injector Solenoids”.
Wastegate
Verify that the exhaust bypass valve for the wastegate
canclose.UseCatETtooverridethewastegateto0
percent. Perform a torque converter stall test. After
30 seconds, a high boost pressure event should
result. If a high boost pressure event occurs, the
wastegate is opening properly.
Engine Speed/Timing Signal
Check Cat ET for the following logged Diagnostic
Code 190-08. Refer to the diagnostic functional test
Troubleshooting, “Engine Speed/Timing Sensor”.
Active Engine Derate
Connect Cat ET and check for “ACTIVE” engine
derates. If the active engine derate is due to “Axle
Protection”, refer to the Service Manual for the
transmission or implement control. Perform the
torque converter stall test. Compare the achieved
stall speed to specifications. If the output meets
specifications, continue with diagnostic checks.