879194Q01 Mercruiser BELT, Serpentine

sensor:Mechanical Calibration - During a manual calibration, two set screws on the throttle position sensor are adjusted. The set screws are for low idle stop and high idle stop.Electronic Calibration - During an electronic calibration, the Caterpillar Electronic Technician (ET) is used to set the PWM that is equal to low idle and the PWM that is equal to high idle.Test Step 1. Inspect the Throttle's Components
Turn the keyswitch to the OFF position.
Inspect the throttle linkage and related components for the following conditions:
Loose
Bent
Broken
Missing
WornExpected Result:The throttle linkage and related components are in good condition.Results:
OK - The throttle linkage and related components are in good condition. Proceed to Test Step 2.
Not OK - The throttle linkage and related components are not in good condition.Repair: Repair the throttle linkage. Replace parts, if necessary. Continue with this procedure when the components for the throttle linkage are in good condition.STOPTest Step 2. Determine the Type of CalibrationDetermine the type of calibration to be performed.Results:
Mechanical - Proceed to Test Step 3.
Electronic - Proceed to Test Step 5.Test Step 3. Adjust the Throttle at Low Idle
Connect Cat ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Turn the keyswitch to the ON position. Do not start the engine.
Observe the value of the "Throttle Position" on Cat ET.
Move the throttle to low idle. Adjust the throttle linkage and adjust the low idle set screw until the "Throttle Position" is zero percent.
Increase the throttle. Verify that the value of the "Throttle Position" increases.Expected Result:When the throttle is at low idle, the "Throttle Position" is zero percent. As you increase the throttle, the value of the "Throttle Position" increases.Results:
OK - When the throttle is at low idle, the "Throttle Position" is zero percent. As you increase the throttle, the value of the "Throttle Position" increases. The low idle adjustment is correct. Proceed to Test Step 4.
Not OK - When the throttle is at low idle, the "Throttle Position" is zero percent. Alternatively, as you increase the throttle, the value of the "Throttle Position" does not increase. There is a problem with the throttle position sensor.Repair: Refer to Troubleshooting, "Throttle Postion Sensor Circuit - Test".STOPTest Step 4. Adjust the Throttle at High Idle
Move the throttle to high idle. Adjust the throttle linkage and/or adjust the high idle set screw until the "Throttle Position" is 100 percent.Note: When you adjust the high idle on some types of linkage, the low idle adjustment may change.
Verify that low idle is correctly adjusted. Make adjustments, if necessary.Expected Result:When the throttle is at high idle, the "Throttle Position" is 100 percent. When the throttle is at low idle, the "Throttle Position" is zero percent.Results:
OK - When the throttle is at high idle, the "Throttle Position" is 100 percent. When the throttle is at low idle, the "Throttle Position" is 0 percent. Calibration of the throttle is complete.STOP
Not OK - The high idle position and/or the low idle position cannot be adjusted to the specification. An electronic calibration is required. Proceed to Test Step 5.Test Step 5. Calibrate the Throttle at Low Idle
Connect Cat ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Turn the keyswitch to the ON position. Do not start the engine.
Move the throttle to low idle.
Observe the "Throttle Position" on the status screen of Cat ET.
Verify that the "Throttle Position" is zero percent.Expected Result:The "Throttle Position" is zero percent when the throttle is at low idle.Results:
OK - The "Throttle Position" is zero percent when the throttle is at low idle. Proceed to Test Step 6.
Not OK - The "Throttle Position" is not zero percent when the throttle is at low idle.Repair: Perform the following procedure:
Adjust the value of the "Throttle Input Low Idle Duty Cycle Setpoint" on the "Configuration" screen of Cat ET.
Verify that the "Throttle Position" is zero percent when the throttle is at low idle. Proceed to Test Step 6.Test Step 6. Configure the Calibration for High Idle
Move the throttle to high idle.
Check the "Throttle Position" on the status screen of Cat ET.
Verify that the "Throttle Position" is 100 percent.Expected Result:The "Throttle Position" is 100 percent when the throttle is in high idle.Results:
OK - The "Throttle Position" is 100 percent when the throttle is at high idle. Calibration of the throttle is complete.STOP
Not OK - The "Throttle Position" is not 100 percent when the throttle is at high idle.Repair: Perform the following procedure:
Adjust the "Throttle Input High Idle Duty Cycle Setpoint" on the "Configuration" screen on Cat ET.
Verify that the "Throttle Position" is 100 percent when the throttle is at high idle.STOP