16/5/24 SIS 2.

Injector solenoid circuit - Test (RSNR9318-12)

SMCS- 1290 i05387027

Description of the System Operation:

Use this procedure under the following conditions:

It is suspected that there is a problem with an injector solenoid.

You have been directed to this procedure from Localization and Troubleshooting,
Location and troubleshooting without a diagnostic code.

There is an active diagnostic code for an injector solenoid.

Use this procedure for the following diagnosis codes:

1-05 Open circuit of injector cylinder 1

1-06 Short circuit in cylinder 1 of the injector

2-05 Open circuit of injector cylinder 2

2-06 Short circuit in injector cylinder 2

3-05 Open circuit of injector cylinder 3

3-06 Short circuit in cylinder 3 of the injector

4-05 Open circuit of injector cylinder 4

4-06 Short circuit in injector cylinder 4

5-05 Open circuit of cylinder 5 of the injector

5-06 Short circuit in injector cylinder 5

6-05 Open circuit of cylinder 6 of the injector

6-06 Short circuit in cylinder 6 of the injector

Carry out this procedure under conditions that are identical to the existing conditions.
when the problem occurs. Normally, issues with the injector solenoid
They occur when the engine is heated or when the engine is vibrating (heavy loads).

These engines have mechanically actuated electronic unit injectors (EUI) and
electronically controlled. The Engine Control Module (ECM) sends a pulse of 105
volts to each injector solenoid. The impulse is sent at the right moment and with the
correct duration for a charge and determined speed of the motor. The solenoid is mounted
at the top of the fuel injector nozzle.
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If an open circuit is detected in the solenoid circuit, a diagnostic code is generated.

The ECM continues trying to activate the injector. If a short circuit is detected, a
diagnostic code. The ECM will deactivate the solenoid circuit. The ECM will attempt
periodically activate the injector. If the short circuit persists, this sequence will be repeated
of events until the problem is resolved.

Note: See illustration 2. Two injector solenoids share a supply wire.

For this reason, an open circuit or a short circuit in a supply cable can cause
diagnostic codes for two injector solenoids.

When an injector is replaced, the injector adjustment files must be programmed.

new in the ECM. If the ECM is replaced, all adjustment files must be programmed.
injector in the new ECM. See Location and Troubleshooting, 'Adjustment File
from the injector" for more information.

The Electronic Technician (ET) from Caterpillar includes the following tests that facilitate the
localization and troubleshooting of injector solenoids:

Cylinder deactivation test

The "cylinder deactivation test" is used in an engine to determine performance.

an individual cylinder while the engine is running. As one or more cylinders
disabled during the test, the 'cylinder deactivation test' uses the 'position of
"combustible" from each injector to assess the performance of the remaining cylinders that are
They are lighting up. As the different cylinders are deactivated, a ...
comparison of the change in the "fuel position" to identify the cylinders that are.
weak or failing. One reason for a cylinder to be weak or failing is an injector that has
a mechanical failure.

During the test, when an injector that is in good condition is deactivated, the
The "fuel position" of the remaining injectors will show a constant change. This
constant change in the "fuel position" is due to the remaining injectors being
compensating for the injector that has been deactivated. If an injector is disconnected with a
defect, the "fuel position" will not show a proportional change. This change
the imbalance is due to the fact that a smaller amount of fuel is needed to compensate
the loss of power of the injector with the defect. The 'cylinder deactivation test'
It is used to isolate a injector with a defect and avoid having to change injectors that
they are in good condition.

Note: Before performing the 'cylinder deactivation test', all must be resolved
active diagnosis codes.

Injector solenoid test

Use the 'injector solenoid test' to diagnose an open circuit or a short circuit.
in the injector solenoid wires. While the engine is off, the 'test of

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The injector solenoid briefly activates each of the injector solenoids. A solenoid
in good condition will produce an audible click when the solenoid is activated. After
test it, the Cat ET shows the solenoid status as 'OK', 'Open' or
Short-circuited

Illustration 1 g01147070
Electronic unit injector

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Illustration 2 g01161139
Diagram of the injector solenoids

Test step 1. Inspection of the electrical connectors and wiring

Danger of electric shock. The unit injector system

electronics use 90 to 120 volts.

A. Disconnect the power supply from the ECM.

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Illustration 3 g01200438
Left side view of the engine (typical example)

ECM Connector J2/P2

J300/P300 connector for the valve cover of the injector

B. Carefully inspect the connectors (1) and (2). Refer to Location and Solution of
Issues, "Electrical connectors - Inspect" for more details.

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Illustration 4 g01099568
Terminal locations in the P2 connector of the ECM

Supply of injector 5 and 6

Supply of injector 1 and 2

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Return of injector 6

Return of injector 3

Return of injector 5

Return of injector 4

Supply of injector 3 and 4

Injector return 1
Injector 2 return

Illustration 5 g01161269
Terminals in the input connector of the J300 injector valve cover.

Supply of injector 5 and 6

(J300-2) Injector 6 return

Supply of injector 3 and 4

Return of injector 5

Return of injector 1

Supply of injector 1 and 2

Return of injector 2

(J300-11) Injector 3 return

Injector 4 return

C. Perform a tensile test of 45 N (10 lb) on each of the cables in the connector.
ECM and each of the cables associated with the injector solenoids.

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D. Check the appropriate pair in the Allen head screw of each ECM connector. Refer to
Localization and Troubleshooting, 'Electrical Connectors - Inspect' to obtain
the values of the correct pairs.

E. Check the wire harness and cables for abrasions or pinch points.
from the injectors to the ECM.

Expected result:

All connectors, plugs, and sockets are fully coupled or inserted.

cable bundle and the cables are free of corrosion, abrasion or pinch points.

Results:

CORRECT - The connectors and wiring appear to be in good condition.

Continue with Test Step 2.

INCORRECT - There is a problem with the connectors or the cables.

Repair: Repair or replace the connectors or the wiring. Make sure that all
the seals are placed correctly and that the connectors are completely
coupled. Verify that the repair solves the problem.

STOP

Test step 2. Check to see if there are any registered diagnostic codes for the
injector solenoids.

A. Connect the Cat ET to the data link connector. Refer to Localization and Troubleshooting
Problems, "Electronic service tools".

B. Restore the electrical current to the engine's ECM.

C. Check to see if there are any diagnostic codes registered for the injector solenoids
in the Cat ET.

Expected result:

There is no diagnostic code registered for the injector solenoids.

Results:

CORRECT - No diagnostic code has been recorded. The solenoids of the

Injectors operate correctly. There may be a mechanical problem with the supply of
injector fuel. Continue with Test Step 3.

INCORRECT - One or more diagnosis codes have been registered. There may be a
Electrical problem in the injector circuit. Proceed with Test Step 4.

Test step 3. Execute the 'cylinder deactivation test'

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A. Start the engine.

B. Let the engine warm up to the normal operating temperature (approximately

77 °C (171 °F)

C. After the engine warms up to operating temperature, access the 'Test of

deactivation of the cylinder" through the following screens in the order indicated:

Diagnostics

Diagnostic Tests

Cylinder deactivation test

D. Turn off all parasitic loads like the air conditioning and air compressors
that can affect the test results.

E. Select the start button at the bottom of the screen for the test
deactivation of the cylinder in the Cat ET.

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Cylinder deactivation tests are interactive, so the procedure is
guided from start to finish. The cylinder deactivation test will establish the speed
correct engine for the application.

Expected result:

The variation in the fuel regime of all cylinders is within the

specifications.

results

CORRECT - The cylinder deactivation test indicates that all the injectors
function correctly.
Repair: If a problem with the fuel system is suspected and the codes of
diagnosis are not active or registered, refer to Systems Operation/Tests and
Settings to view information related to the low-pressure fuel system.

If a diagnostic code is produced as a result of the 'deactivation test'

from the cylinder, continue with test step 4.

INCORRECT - The cylinder deactivation test indicates that at least one of the
injectors do not work properly.
Repair: Check that the engine's valve clearance for that injector is adjusted.
correctly. Run the 'cylinder deactivation test' again. If the problem
it is still present, replace the injector. Change the injector adjustment file in the
ECM. Refer to Troubleshooting, 'Injector Adjustment Files'.

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Stop

Test step 4. Perform the "Injector solenoid test".

A. Start the engine.

B. Let the engine warm up to the normal operating temperature (approximately

77 °C (171 °F).

C. Stop the engine.

D. Restore the electrical current to the engine ECM.

E. Go to the "Injector Solenoid Test"; for this, access the following screens
in the order indicated:

Diagnostics

Diagnostic Tests

Injector solenoid test

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As the ECM energizes each of the solenoids, a click can be heard in the cover.
of valves. Check the activation of each solenoid by comparing the location of the click with
the progress shown in the Cat ET.

H. Perform the injector solenoid test at least twice.

Expected result:

All cylinders indicate 'OK' in Cat ET.

Resultados

CORRECT - There is no electronic problem with the injectors at this moment.

Repair: It seems that the issue is resolved. The problem may have been caused
due to a poor electrical connection in a connector. If the codes continue to be recorded,
consult Location and Troubleshooting, 'Electrical Connectors - Inspect'. If the
the engine is racing or has low power, consult Troubleshooting, 'The engine is racing,'
it works with difficulty or is unstable" or Troubleshooting, "Low or poor power,
or lack of response to the accelerator.

STOP

Incorrect - "Open" - Observe the cylinder that indicates "Open". Continue with the
Test step 5.

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Incorrect - 'Short Circuit' - Observe the cylinder that indicates 'Short'.

Continue with Test Step 6.

Test step 5. Check the wiring harness between the ECM and the valve cover base
to determine if there is an open circuit.

Risk of electric shock. The unit injector system

electronics use 90 to 120 volts.

A. Disconnect the power supply from the ECM.

B. Disconnect the input connector of the valve cover of the J300/P300 injector at the base
from the valve cover.

C. Restore the electric current to the engine's ECM.

D. Make a jumper cable that is long enough to create a short circuit in the
different terminals in the P300 connector. Bevel the pins of the connector on both sides
ends of the bridge cable.

Illustration 6 g01161290
Connectors of the input terminal of the valve cover of the injector P300 (terminal side)

Supply of injector 5 and 6

Return of injector 6

Supply of injector 3 and 4

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16/5/24 SIS 2.0
Injector 5 return

Return of injector 1

Supply of injector 1 and 2

Injector 2 return

Return of injector 3
Return of injector 4

E. Insert one end of the jumper cable into the P300 connector socket of the cable.
supply of the suspicious injector. Insert the other end of the jumper cable into the
connector plug P300 of the return cable of the suspected injector. This will replace
the injector solenoid with a short circuit.

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G. Repeat this test for each suspicious circuit. Stop the 'solenoid test of
"injection" before touching the jumper cable. Restore the wires to the original configuration.

Expected result:

The Cat ET shows "Short" (Short-circuit) for each of the circuits where it has been
bridge cable installed.

Results:

CORRECT - The Cat ET shows 'Short' for each circuit in which it

he connected the jumper cable. The wire harness between the ECM and connector P300 does not have a
open circuit. Proceed to Test Step 7.

INCORRECT - The Cat ET shows "Open" for the cylinder with the jumper cable.
There is a problem in the wiring between the ECM and the P300 connector. Proceed with the Step of
test 8.

Test step 6. Check the wiring harness between the ECM and the valve cover base.
to see if there is a short circuit

Electric shock hazard. The unit injector system

Electronics use 90 to 120 volts.

A. Disconnect the power supply from the ECM.

B. Disconnect the P300 connector.

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C. Restore the electrical current to the engine ECM.

D. Perform the 'injector solenoid test' a minimum of two times.

Expected result:

All the cylinders indicate 'Open' in the Cat ET.

Results:

CORRECT - All cylinders indicate an 'Open' in Cat ET. The harness of

Cables between the ECM and connector P300 do not have a short circuit. Proceed with the Step of
test 7.

INCORRECT - One or more cylinders indicate "Short (Short Circuit)" in the Cat ET.Register
the cylinders that indicate "Short" (short circuit). Proceed with Test Step 8.

Test step 7. Check the injector wiring harness under the valve cover
to see if there is an open circuit or a short circuit.

Danger of electric shock. The unit injector system

electronics use 90 to 120 volts.

A. Disconnect the power supply of the ECM.

B. Remove the valve cover to access the suspicious injector.

C. Disconnect the wiring harness connector from the suspected injector.

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Illustration 7 g01147088
Connector terminals for the injector solenoid

D. Thoroughly clean the terminals on the injector solenoid and at the harness connector.
cables.

E. Use a jumper cable to create a short circuit at the terminals of the connector for the
suspicious injector. This will effectively replace the injector solenoid with a
short circuit

Restore the electrical current to the engine ECM.

G. Perform the "injector solenoid test" at least twice.

Note: The injector solenoid that shares the injector supply wire that is
Short-circuiting can indicate a false test result. Ignore this result of
test.

H. Remove the power supply from the ECM.

I. Remove the jumper wire from the injector connector. This effectively replaces the solenoid.
of the injector with an open circuit.

J. Restore the electrical current to the engine ECM.

K. Perform the 'injector solenoid test' at least two times.

L. Disconnect the electrical power supply from the ECM.

Expected result:

The Cat ET shows "Short" (Short Circuit) for the cylinder that has the jumper wire, and "Open".
(Open) when the jumper cable is removed.

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Results:

CORRECT - Cat ET correctly shows the correct status during the test. The bundle
the cables are in good condition.
Repair: Use a multimeter to check the resistance of the injector solenoid
suspicious. The correct resistance of each injector solenoid is 1.06 ± 0.05
ohms. If the resistance of the solenoid is not within specifications, replace the
defective injector. Check that the problem has been resolved. If the resistance of
the solenoid is within specifications, the problem may be intermittent. If the
the problem is intermittent, check the diagnostic functionality test in
Localization and Troubleshooting, 'Electrical connectors - Inspect'. Check that
the repair solves the problem.

STOP

INCORRECT - The Cat ET did not correctly show the correct status during the test. There is
a problem in the wiring harness of the injector under the valve cover. It may
there is a problem in a connector.
Repair: Repair the cables or the connector when possible. Replace the parts, if
It is necessary. Check that the problem has been resolved.

STOP

Test step 8. Check that the ECM is functioning correctly.

Danger of electric shock. The unit injector system

electronic devices use 90 to 120 volts.

A. Disconnect the electrical power supply from the ECM.

B. Prepare a jumper cable long enough to reach from the connector of

ECM P2 to the motor ground connection terminal. Chisel a terminal for the key.
of cube at one end of the bridge cable.

C. Disconnect the P2 connector.

D. Disconnect the supply cable for the suspicious injector from the ECM connector. Install the
bridge cable in the receptacle.

E. Connect the ECM connector J2/P2.

F. Check that the ECM detects an open circuit in the suspected injector:

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a. Ensure that the bridging cable is not in contact with a connection source.
ground or another circuit. Do not touch the jumper wire during the test. There is a great danger.
electric shock in the jumper cable while the test is being carried out.

b. Restore the electrical current to the engine's ECM.

c. Perform the "injector solenoid test" at least two times.

d. Disconnect the power supply from the ECM.

The Cat ET shows 'Open' for the two injectors that share the
supply cable.

G. Verify that the ECM detects a short circuit in the suspected injector:

a. Connect the jumper cable to the motor's ground connection terminal. Do not touch the cable.
bridge during the test. There is a great danger of electric shock in the cable.
bridge while the test is being executed.

b. Restore the electrical current to the engine ECM.

c. Perform the 'injector solenoid test' at least twice.

d. Disconnect the power supply from the ECM.

The Cat ET shows 'Short' (Short circuit) for the two injectors that share.
the supply cable.

Expected result:

Cat ET shows the correct state of each test circuit.

Results:

CORRECT - The ECM detects the correct state of the circuit. There is an open circuit or a
short circuit in the engine wiring harness. There may be a problem with a connector.
Repair: Inspect to determine if there is moisture or corrosion on the connectors.
Repair the cables or the connector when possible. Replace the parts if it is
necessary. Delete all diagnostic codes after completing this step of
test. Check that the problem has been resolved.

STOP

INCORRECT - The ECM does not detect the correct status of the circuit.
Repair: There is a problem with the ECM. Replace the ECM. Refer to Location and
problem solving, 'ECM Replacement'. Verify that it has been resolved
problem.

STOP

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PIP-10583166
May 16, 2024
21:24:32-05:00
i02403860
© 2024 Caterpillar Inc.

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