882452 Mercruiser PLATE, Cam End

Table 1
Diagnostic Codes Table    
Description     Conditions which Generate this Code     System Response    
338-5 Engine Pre-Lube Pump Relay current below normal     The engine's Electronic Control Module (ECM) detects an open in the circuit for the engine 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 has the ability to automatically lubricate the engine before cranking. This may increase the life of certain engine parts by lubricating these parts before the starting motor is engaged.The prelubrication system is activated at ECM powerup. The ECM prevents the starting motor from engaging while the pump builds pressure in the engine's lubrication system. The ECM uses engine oil temperature and engine coolant temperature to determine engine temperature. The ECM also uses engine rpm and engine oil pressure to determine if the prelubrication is viable.The prelubrication system will not activate if the engine has been running within the last two minutes or if the prelubrication system has been activated within the last two minutes.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.
Illustration 1 g01402185
Schematic for the prelubrication systemTest Step 1. Inspect Electrical Connectors and Wiring
Remove electrical power from the ECM.
Illustration 2 g01139425
ECM (1) J1/P1 connectors (2) J2/P2 connectors
Thoroughly inspect the J1/P1 and thoroughly inspect the J2/P2 ECM connectors. Thoroughly inspect any connectors that are associated with the prelubrication system. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01402455
P1 ECM connector (P1-34) Prelubrication relay
Check the torque of the allen head screws for the ECM connectors.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the analog sensors.
Check the harness and wiring for abrasion and for pinch points from the analog sensors 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. All connections and grounds are tight and free of corrosion.Results:
OK - The connectors and wiring appear to be OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not OK.Repair: Perform the necessary repairs and/or replace parts, if necessary. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOPTest Step 2. Verify Operation of the Prelubrication Oil Pump
Restore electrical power to the ECM. The engine should not be running.
Proceed to the "Diagnostic Override Screen" in Cat ET.
Activate the prelubrication system.Expected Result:The prelubrication oil pump activates.Results:
OK - The prelubrication oil pump activates. The prelubrication system is functioning properly.Repair: If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - The prelubrication oil pump does not activate. Proceed to Test Step 3.Test Step 3. Check the Power Supply to the Prelubrication Relay
Measure the voltage between terminal 87 (+Battery) of the prelubrication relay and chassis ground.Expected Result:The voltage is 24.0 8.0 VDC.Results:
OK - The supply voltage is 24.0 8.0 VDC. Proceed to Test Step 4.
Not OK - The supply voltage is not 24.0 8.0 VDC. There is a problem in the wiring between the prelubrication relay and the +Battery.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 4. Check the Output Voltage of the Prelubrication Relay
Proceed to the "Diagnostic Override Screen" in Cat ET.
Activate the prelubrication system.
Measure the voltage between terminal 30 (+Battery) of the prelubrication relay and chassis ground.Expected Result:The voltage is 24.0 8.0 VDC.Results:
OK - The output voltage is 24.0 8.0 VDC. Proceed to Test Step 10.
Not OK - The output voltage is not 24.0 8.0 VDC. Proceed to Test Step 5.Test Step 5. Check the Resistance of the Prelubrication Relay
Remove electrical power from the ECM.
Measure the resistance across terminal 85 (signal input) and terminal 86 (ground terminal) of the prelubrication relay.Expected Result:The resistance is between 250 Ohms and 500 Ohms.Results:
OK - The resistance is between 250 Ohms and 500 Ohms. Proceed to Test Step 6.
Not OK - The resistance is not between 250 Ohms and 500 Ohms. The relay is faulty.Repair: Replace the relay.Verify that the repair eliminates the problem.STOPTest Step 6. Check the Signal Voltage to the Prelubrication Relay
Restore electrical power to the ECM. The engine should not be running.
Proceed to the "Diagnostic Override Screen" in Cat ET.
Activate the prelubrication system.
Measure the voltage between terminal 85 (signal voltage) of the prelubrication relay and chassis ground.Expected Result:The voltage is 24.0 8.0 VDC.Results:
OK - The signal voltage is 24.0 8.0 VDC. Proceed to Test Step 10.
Not OK - The signal voltage is not 24.0 8.0 VDC. Proceed to Test Step 7.Test Step 7. Check the Ground Circuit for the Prelubrication Relay
Remove electrical power from the ECM.
Measure the resistance between terminal 86 of the prelubrication relay and chassis ground.Expected Result:The resistance does not indicate an open circuit.Results:
OK - The resistance does not indicate an open circuit. Proceed to Test Step 8.
Not OK - The resistance indicates an open circuit. The ground for the relay for the prelubrication pump is faulty.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 8. Check the Harness to the ECM
Verify the electrical power is removed from the ECM.
Disconnect the J1/P1 ECM connector.
Remove the wire from terminal P1-34 (prelubrication relay signal).
Reconnect the J1/P1 ECM connector.
Disconnect the connector for the prelubrication relay.
Use a suitable piece of wire to short terminal 85 (signal voltage ) and terminal 86 (return) on the connector for the prelubrication relay.
Measure the resistance between the end of the wire from terminal P1-34 (prelubrication relay signal) and chassis ground.Expected Result:The resistance does not indicate an open circuit.R