SWITCH AS-ROCKER 1701328 - Caterpillar

System Operation Description:The engine has Hydraulic Electronic Unit Injectors (HEUI). The Electronic 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. The 105 volt pulse can be individually cut out to aid in troubleshooting misfire problems.If an open is detected in the solenoid circuit, a diagnostic code is generated and the ECM continues to try to fire the fuel injector. If a short is detected, a diagnostic code is generated and the ECM temporarily disables the solenoid circuit. The ECM will then enable the solenoid circuit. This sequence of events will be repeated until the problem is corrected.
Illustration 1 g00687331
Schematic for 8 cylinder engines
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Schematic for 12 cylinder engines
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8 cylinder P2 ECM connector (5) Solenoid 1/3 Return (16) Solenoid 1 Power (17) Solenoid 2/4 Return (26) Solenoid 2 Power (27) Solenoid 5/7 Return (30) Solenoid 7 Power (31) Solenoid 6 Power (32) Solenoid 3 Power (36) Solenoid 8 Power (37) Solenoid 5 Power (38) Solenoid 4 Power (39) Solenoid 6/8 Return
Illustration 4 g00893822
12 cylinder P2 ECM connector (5) Solenoid 1/3 Return (11) Solenoid 2/4 Return (12) Solenoid 12 Power (16) Solenoid 1 Power (17) Solenoid 5/7 Return (18) Solenoid 10 Power (21) Solenoid 6/8 Return (22) Solenoid 8 Power (26) Solenoid 3 Power (27) Solenoid 9/11 Return (28) Solenoid 6 Power (31) Solenoid 11 Power (32) Solenoid 5 Power (33) Solenoid 10/12 Return (34) Solenoid 4 Power (37) Solenoid 9 Power (38) Solenoid 7 Power (40) Solenoid 2 PowerTest Step 1. Inspect Electrical Connectors And Wiring
Electrical shock hazard. The electronic unit injector system uses 90-120 volts.
Turn the keyswitch to the OFF/RESET position. A strong electrical shock hazard is present if the ignition key is not turned OFF.
Thoroughly inspect the J2/P2 ECM connector and the J52/P52 through J58/P58 unit injector connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for abrasion and for pinch points from the injectors to the ECM.Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Logged Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Observe the diagnostic codes on Cat ET.Expected Result:The following diagnostic codes are not logged:
1-05 Injector Cylinder 1 open circuit through
12-05 Injector Cylinder 12 open circuit
1-06 Injector Cylinder 1 short through
12-06 Injector Cylinder 12 shortResults:
OK - None of the diagnostic codes are logged. Proceed to Test Step 3.
Not OK - One or more of the diagnostic codes are logged. Proceed to Test Step 4.Test Step 3. Perform the Injector