TM 9-6115-730-24
0013
ELECTRONIC TECHNICIAN (ET) TROUBLESHOOTING - Continued
SYMPTOM
5.
Injector Solenoid Circuit Test.
System Operation Description:
An injector solenoid may have a problem.
You have been directed to this procedure from WP 0011, Troubleshooting without a Diagnostic Code.
There is an active diagnostic code for an injector solenoid.
Use this procedure for the following diagnostic codes:
1-E-11 Injector Cylinder 1 fault
2-E-11 Injector Cylinder 2 fault
3-E-11 Injector Cylinder 3 fault
4-E-11 Injector Cylinder 4 fault
5-E-11 Injector Cylinder 5 fault
6-E-11 Injector Cylinder 6 fault
Figure 5 shows the injector solenoid circuit. Perform the troubleshooting procedures under conditions that are
identical to the conditions that exist when the problem occurs. Typically, problems with the injector solenoid occur
when the engine is warmed up and/or when the engine is under vibration (heavy loads). These engines have
hydraulically actuated electronically controlled unit injectors (HEUI). The ENGINE CONTROL Module (ECM)
sends a 105 volt pulse to each injector solenoid. The pulse is sent at the proper time and at the correct duration
for a given engine load and speed. The solenoid is mounted on top of the fuel injector body. If an open is
detected in the solenoid circuit, a diagnostic code is generated. The ECM continues to try to fire the injector. If a
short is detected, a diagnostic code is generated. The ECM will disable the solenoid circuit. The ECM will
periodically try to fire the injector. If the short circuit remains, this sequence of events will be repeated until the
problem is corrected. When an injector is replaced, program the new injector code into the ECM. If the ECM is
replaced, all six injector codes must be programmed into the new ECM. Refer to Troubleshooting, Replacing the
ECM for the correct procedure. The Caterpillar Electronic Technician (ET) includes the following tests that aid in
troubleshooting the injector solenoids.
NOTE
Before running the Cylinder Cutout Test, all active diagnostic codes must be repaired.
Cylinder Cutout Test
The Cylinder Cutout Test is used on an engine in order to determine the individual cylinder performance while the
engine is running. As one or more cylinders are cut out during the test, the Cylinder Cutout Test uses the fuel
position of each injector in order to evaluate the performance of the remaining cylinders that are firing. As the
different cylinders are cut out, a comparison of the change in fuel position is used to identify cylinders that are
weak or misfiring. One reason for a cylinder that is weak or misfiring is an injector that is malfunctioning
mechanically. During the test, when a good injector is cut out, the fuel position of the remaining injectors will
show a consistent change. This consistent change in the fuel position is caused by the remaining injectors that
are compensating for the cut out injector. If a malfunctioning injector is cut out, the fuel position will not show a
proportional change. This unbalanced change is the result of the smaller quantity of fuel that is needed to
compensate for the power loss from the malfunctioning injector. The Cylinder Cutout Test is used to isolate a
malfunctioning injector in order to avoid replacement of injectors that are in good repair.
0013-15
