GUIDE-VALVE 6I2865 - Caterpillar

System Operation Description:The switch for oxygen calibration allows the operator to initiate a calibration of the oxygen sensor. The switch has three positions. Normally, the switch is in the center position. This position creates an open circuit.Moving the switch to either the upper position or the lower position closes the circuit. A ground is supplied to the J1-28 input of the ECM.When you release the switch, a spring returns the switch to the center position. The circuit is opened. Replace the switch if the switch does not automatically return to the center position.If the engine speed is zero rpm, an oxygen calibration will begin when the switch returns to the center position. The ECM will display "O2 CALIB".If the engine speed is greater than zero rpm and the switch returns to the center position, a 552-01 diagnostic code is generated. An oxygen calibration will not occur.An oxygen calibration runs for approximately 12 minutes. The calibration will restart if you activate the switch during a calibration.There are no diagnostics for the circuit that initiates an oxygen calibration. If you manipulate the switch and the system does not respond correctly, the circuit is faulty.The most likely cause of a faulty circuit is the switch. The next likely cause is a problem with the wiring. The least likely cause is a problem with the ECM.
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Schematic diagram of the switch for oxygen calibrationThe engine is equipped with a remote control panel that includes a status control module and air/fuel ratio control.
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Schematic diagram of the switch for oxygen calibrationThe engine is configured for Canadian Standards Association (CSA). The engine is equipped with an optional remote control panel with air/fuel ratio control.Test Step 1. Check the Switch for Proper Mechanical Operation
Set the engine control to the "OFF/RESET" mode.
Remove the electrical power from the engine.
Verify that the switch for oxygen calibration is in the center position.
Move the switch to the upper position. Then release the switch. The switch should return to the center position.
Move the switch to the lower position. Then release the switch. The switch should return to the center position.Expected Result:The switch has proper mechanical operation.Results:
OK - The switch has proper mechanical operation. Proceed to Test Step 2.
Not OK - The switch does not return to the center position.Repair: Replace the switch. Verify that the original problem is resolved.STOPTest Step 2. Inspect the Electrical Connectors and the WiringNote: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Thoroughly inspect each of the following connectors:
J1/P1 connectors on the ECM
Connections for the switch for oxygen calibration
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Harness side of the P1 connector (P1-3) Ground for the sensors (P1-28) Switch input for oxygen calibration
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the switch for oxygen calibration.
Check the terminal strips for corrosion and for mechanical failure.
Check the harnesses and the wiring for abrasion and for pinch points between the switch for oxygen calibration and the ECM.Expected Result:The connectors, pins, and sockets are connected