3512C HD and 3516C HD IPP Rental Power Modules Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with a prelubrication system. Also, use this procedure if one of the diagnostic codes in Table 1 is active or easily repeated.

Table 1

Diagnostic Codes Table
J1939 Code	CDL Code	Code Description	System Response
3551-5	338-5	Engine Oil Priming State : Current Below Normal	The Electronic Control Module (ECM) detects an open in the circuit for the prelubrication relay. The ECM detects a short to battery voltage in the circuit for the prelubrication relay. The code is logged.
3551-6	338-6	Engine Oil Priming State : Current Above Normal	The ECM detects a short in the circuit for the prelubrication relay. The code is logged.

The ECM can lubricate the engine before cranking begins. This engine prelubrication is used to increase the life of certain engine parts by lubricating these parts before the starting motor is engaged.

There are several configuration parameters that define the operation of the prelubrication system. Prior to troubleshooting problems that are associated with the prelubrication system, check the settings of these parameters. Be sure that you understand the proper operation of the system.

The charge pressure status of the prelubrication system may be communicated to several different controllers that are on the application. Depending on the status that is communicated there could be an effect on the engine starting. The following status indicators are communicated over the data link:

• "Prelube OFF" or "Prelube disabled"

• "Prelube waiting for oil"

• "Prelube waiting to fill"

• "Perlube ready to start"

• "Prelube failed"

• "Prelube ready to start"

• "Continuous prelube"

Some of these status indicators report the parameter settings of the prelubrication system. The ECM determines the charge pressure status via the engine oil pressure sensor.

The prelubrication system is activated at ECM powerup. The ECM prevents the starting motor from engaging while the pump builds pressure in the lubrication system.

Also, a manual prelube switch may be wired to P1-60 terminal at the ECM connector. When this ECM input is grounded, the ECM will activate the prelubrication relay.

An override for the prelubrication system is available in Caterpillar Electronic Technician (ET). The override allows the technician to activate the prelubrication system for service and testing. The test is functional only when the engine speed is zero rpm. The test is accessed by selecting the following menus on Cat ET:

• "Diagnostics"

• "Diagnostic Tests"

• "Override Parameters"

Illustration 1	g03658065
Schematic for the prelubrication system

Illustration 2	g01155187
Locations of the terminals at the harness connector for the prelubrication relay (Terminal 1) Prelubrication relay (Terminal 2) Digital return

Table 2

Troubleshooting Test Steps	Values	Results
1. Inspect the Electrical Connectors and the Wiring A. Remove the electrical power from the ECM. B. Thoroughly inspect connectors (2), (3), and (4). Also, thoroughly inspect the other connectors for the prelubrication relay that are in the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the proper procedure for inspecting the connectors and the wiring. C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors and the other connections that are associated with the circuit. D. Check the allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. E. Check the harness and the wiring for abrasion and for pinch points.	Connectors	Results: The connectors and wiring appear to be OK. Proceed to Test Step 2 Results: There is a problem in the connectors and/or wiring. Repair The connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled. Verify that the repair eliminates the problem.
2. Check for Active Diagnostic Codes A. Connect Cat ET to the service tool connector. B. Restore the electrical power to the ECM. C. Monitor the active diagnostic code screen on Cat ET. Check the prelubrication system for an active diagnostic code. Note: Wait at least 30 seconds in order for the diagnostic codes to become active. D. Select diagnostic tests from Cat ET. E. Select the "Override Parameters" screen on Cat ET. F. Activate the override for the prelubrication system. G. Monitor the active diagnostic code screen on Cat ET. Check the prelubrication system for an active diagnostic code. Note: Wait at least 30 seconds in order for the diagnostic code to become active. H. Disable the override for the prelubrication system.	Active codes	Results: No diagnostic codes are active, but a problem is suspected in the prelubrication system. Proceed to Test Step 6 Results: A -6 diagnostic code is active at this time. A short is detected in the circuit for the prelubrication relay. Proceed to Test Step 3 Results: A -5 diagnostic code is active at this time. An open is detected in the circuit for the prelubrication relay. Proceed to Test Step 4
3. Create an Open Circuit at the Control Circuit of the Prelubrication Relay A. Remove the electrical power from the ECM. B. Disconnect the control inputs from the blade terminals at the prelubrication relay. C. Restore the electrical power to the ECM. D. Monitor the active diagnostic code screen on Cat ET. Check the prelubrication system for an active diagnostic code. Note. Wait at least 30 seconds in order for the diagnostic codes to become active. E. Select diagnostic tests from Cat ET. F. Select the "Override Parameters" screen on Cat ET. G. Activate the override for the prelubrication system. H. Monitor the active diagnostic code screen on Cat ET. Check for an active diagnostic code for the prelubrication system. Note: Wait at least 30 seconds in order for the diagnostic code to become active. I. Remove the electrical power from the ECM.	Open Circuit	Results: A -6 diagnostic code was active before disconnecting the wire. A -5 diagnostic code became active after disconnecting the wire. Repair: The harness and the ECM are OK. The short circuit is in the prelubrication relay. Perform the following repair: 1. Temporarily connect a new prelubrication relay. 2. Recheck the circuit in order to ensure that the original problem is resolved with the installation of the new relay. 3. If the problem is resolved with the new relay, reinstall the suspect relay. If the problem returns with the installation of the suspect relay, permanently install the new relay. Clear any logged diagnostic codes. Results: A -6 diagnostic code remains active. There is a short between the prelubrication relay and the ECM. There may be a problem with the ECM. Proceed to Test Step 5
4. Create a Short at the Control Circuit of the Prelubrication Relay A. Remove the electrical power from the ECM. B. Fabricate a jumper wire that is long enough to create a short circuit between the terminals of the harness connector sockets at the prelubrication relay. Crimp blade terminals to each end of the jumper wire. C. Install the jumper wire between the terminals of the harness connector at the prelubrication relay. D. Restore the electrical power to the ECM. E. Select diagnostic tests from Cat ET. F. Select the "Override Parameters" screen on Cat ET. G. Activate the override for the prelubrication system. H. Monitor the active diagnostic code screen on Cat ET. Check for an active diagnostic code for the prelubrication system. Note: Wait at least 30 seconds in order for the diagnostic code to become active. I. Disable the override for the prelubrication system. J. Remove the electrical power from the ECM. K. Restore the wiring to the original configuration.	Control circuit	Results: A -6 diagnostic code is active when the jumper wire is installed. A -5 diagnostic code is active when the jumper wire is removed. Repair: The engine harness and the ECM are OK. The open circuit is in the coil of the prelubrication relay. Perform the following repair: 1. Temporarily connect a new prelubrication relay. 2. Recheck the circuit in order to ensure that the original problem is resolved with the installation of the new relay. 3. If the problem is resolved with the new relay, reinstall the suspect relay. If the problem returns with the installation of the suspect relay, permanently install the new relay. Clear any logged diagnostic codes. Results: The -5 diagnostic code remains active with the jumper in place. The open circuit is between the ECM and the connector for the prelubrication relay. There may be a problem with the ECM. Proceed to Test Step 5
5. Test for the Proper Operation of the ECM A. Remove the electrical power from the ECM. B. Fabricate two jumper wires that are long enough to create a test circuit at the ECM connector. Crimp a connector socket to one end of each of the jumper wires. C. Disconnect the J1/P1 and J2/P2 ECM connectors. D. Remove the wires from terminal locations P1-12 and P2-14 at the ECM connectors. Install one of the jumper wires into each of these terminal locations. E. Connect the ECM connectors. F. Hold the loose ends of each of the jumper wires away from any components in order to create an open circuit condition. G. Restore the electrical power to the ECM. H. Monitor the active diagnostic code screen on Cat ET. Check the prelubrication system for an active -5 diagnostic code. Note: Wait at least 30 seconds in order for the diagnostic code to become active. I. Select diagnostic tests from Cat ET. J. Select the "Override Parameters" screen on Cat ET. K. Activate the override for the prelubrication system. L. Disable the override for the prelubrication system. M. Short circuit the loose ends of the jumper wires that are for the prelubrication relay. N. Restore the electrical power to the ECM. O. Monitor the active diagnostic code screen on Cat ET. Check the prelubrication system for an active diagnostic code. Note: Wait at least 30 seconds in order for the diagnostic codes to become active. P. Select diagnostic tests from Cat ET. Q. Select the "Override Parameters" screen on Cat ET. R. Activate the override for the prelubrication system. S. Disable the override for the prelubrication system. T. Remove the electrical power from the ECM. U. Restore the wiring to the original configuration.	ECM	Results: A -5 diagnostic code is active when the wires are open at the ECM connector. A -6 diagnostic code is active when the wires are shorted at the ECM connector. Repair: The ECM is operating properly. The problem is in the wiring between the ECM and the prelubrication relay. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the original problem has been resolved. Results: One of the following conditions exists: The -5 diagnostic code is not active when the loose ends of the wires for the prelubrication relay are open at the ECM connector. The -6 diagnostic code is not active when the loose ends of the wires for the prelubrication relay are shorted at the ECM connector. Repair: There appears to be a problem with the ECM. Before you consider replacing the ECM, consult with the Dealer Solutions Network for assistance.