MOUNTING GP-SENSOR 3314039 - Caterpillar

The engine oil pressure lamp is used to indicate that a low oil pressure condition exists and/or a diagnostic code for low oil pressure has been generated. The Electronic Control Module (ECM) signals the monitor to activate the lamp when the following diagnostic codes are active:
286-05 EMS Oil Lamp open/short to ground
286-06 EMS Oil Lamp short to +battWhen the ECM determines that the engine oil pressure is low, the ECM will drive an output to a high state. The output signal is supplied to the monitor. The monitor will illuminate a lamp when the output signal from the ECM is at a high state. The ECM reduces engine speed to less than 1450 rpm when the engine oil pressure is low. The ECM will drive the output to a low state when the engine oil pressure is in a safe range.When the engine is started, the lamp will turn on for a minimum of five seconds.
Illustration 1 g02070554
Schematic for low oil pressure lamp
Illustration 2 g01117101
P1 ECM connector
(P1-28) Low engine oil pressure lamp Test Step 1. Inspect Electrical Connectors And Wiring
Thoroughly inspect the J1/P1 ECM connector and the wiring that is associated with the low engine oil pressure lamp. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on P1-28 (low engine oil pressure lamp).
Check the allen head screw on each ECM connector and the customer connector for the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for abrasions and for pinch points from the battery to the ECM. Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: 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 completely coupled.STOPTest Step 2. Check the Wiring from the ECM to the Monitor
Remove the electrical power from the ECM.
Disconnect the connector J1/P1 for the machine harness.
Check the wiring from P1-28 to terminal 8 of the monitor. Use a multimeter to check for shorts to ground and for open circuits. Expected Result:The wiring from P1-28 to terminal 8 of the monitor does not have any open circuits or short circuits.Results:
OK - The wiring for the circuit of the engine oil pressure lamp is OK. Proceed to Test Step 3.
Not OK - There is a problem in the machine wiring. Repair the machine wiring, as required.STOPTest Step 3. Check For Normal Operation Of The Lamp
Monitor the low engine oil pressure lamp.
Restore the electrical power to the ECM. The lamp should turn on for five seconds. Then, the lamp should turn off.
The lamp will remain on if there is an active diagnostic code. If there is an active diagnostic code, connect the Caterpillar Electronic Technician (ET) in order to read