83579M Mariner STOP, MAGNETO BASE

Illustration 1 g01070462
Illustration 2 g01070465
Schematic
Illustration 3 g01070468
Terminal locations at the ECM
Illustration 4 g00810608
Terminal locations at the sensor connectorTest Step 1. Check for Active +5 V Sensor Supply Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the data link connector.
Turn the keyswitch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.
Verify if any of the following diagnostic codes are active:
232-3 5 Volt Supply voltage high
232-4 5 Volt Supply voltage lowExpected Result:Neither of the preceding diagnostic codes are active.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Perform the following diagnostic procedure: Troubleshooting, "5 Volt Engine Pressure Sensor Supply Circuit - Test".STOPTest Step 2. Inspect the Electrical Connectors and the Wiring
Thoroughly inspect the J2/P2 ECM connector and the connectors for any suspect sensors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the sensor connectors that are associated with the active diagnostic code.Refer to Illustration 3.
Check the allen head screws for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque value.
Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM.Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring should be free of corrosion, of abrasion or of pinch points.Results:
OK - Proceed to Test Step 3.
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.Verify that the repair eliminates the problem.Clear all logged diagnostic codes.STOPTest Step 3. Determine the Condition that is Present
Turn the keyswitch to the ON position. Wait at least 30 seconds for activation of the diagnostic codes.
Monitor the active diagnostic code screen on Cat ET.
Determine if the problem is related to a "voltage high" diagnostic code (open circuit) or a "voltage low" diagnostic code (short circuit).Expected Result:Either a "voltage low" diagnostic code (short circuit) is active or a "voltage high" diagnostic code (open circuit) is active.Results:
Voltage low (short) - A "voltage low" diagnostic code (short circuit) is active at this time. Proceed to Test Step 4.
Voltage high (open) - A "voltage high" diagnostic code (open circuit) is active at this time. Proceed to Test Step 7.Test Step 4. Disconnect the Suspect Sensor and Check for an Active Diagnostic Code
Turn the keyswitch to the OFF position.
Disconnect the sensor with the "voltage low" diagnostic code (short circuit).
Turn the keyswitch to the ON position. Wait at least 30 seconds for activation of the diagnostic codes.
Check for an active "voltage high" diagnostic code (open circuit) for the disconnected sensor.Expected Result:A "voltage high" diagnostic code (open circuit) for the disconnected sensor is now active.Results:
OK - A "voltage low" diagnostic code (short circuit) was active before disconnecting the sensor. A "voltage high" diagnostic code (open circuit) became active after disconnecting the sensor.Repair: Temporarily connect a new sensor.Check for active diagnostic codes.If the new sensor fixes the problem, reconnect the suspect sensor.If the problem returns, permanently install the new sensor.Verify that the repair eliminates the problem.STOP
Not OK - There is a short circuit between the sensor and the ECM.Repair: Leave the suspect sensor disconnected. Proceed to Test Step 5.Test Step 5. Create an Open Circuit at the ECM
Turn the keyswitch to the OFF position.
Remove the signal wire of the suspect sensor from the P2 ECM connector.
Turn the keyswitch to the ON position.
Check for active diagnostic codes.Expected Result:A "voltage high" diagnostic code (open circuit) became active after disconnecting the signal wire.Results:
OK - A "voltage low" diagnostic code (short circuit) was active before disconnecting the sensor. A "voltage high" diagnostic code (open circuit) became active after disconnecting the sensor. Proceed to Test Step 6.
Not OK - There is still a "voltage low" diagnostic code (short circuit).Repair: Connect a test ECM.If the test ECM fixes the problem, reconnect the suspect ECM.If the problem returns, permanently replace the suspect ECM.Verify that the repair eliminates the problem.STOPTest Step 6. C