0317936 JOHNSON WASHER, Vacuum switch

Table 1
CDL Code and Description Conditions which Generate the Code System Response
338-5
Engine Pre-Lube Pump Relay : 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.
338-6
Engine Pre-Lube Pump Relay : Current Above Normal The ECM detects a short in the circuit for the prelubrication relay. 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 primary ECM connector. When this ECM input is grounded, the ECM will activate the prelubrication relay. Refer to Troubleshooting, "Switch Circuits - Test" for information related to troubleshooting this switch circuit.An override for the prelubrication system is available in Cat® 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 g06320888
Schematic for the prelubrication system
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 the electrical connectors for the components in the schematic above. 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 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 currently. A short is detected in the circuit for the prelubrication relay.
Proceed to Test Step 3
Results: A -5 diagnostic code is active currently. 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 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