860008 Mercruiser SCREW, (.250-20 x .625) Torx

If a fault occurs with the primary throttle and a secondary throttle is installed, the engine will use the secondary throttle until the fault is repaired.If a fault occurs with the secondary throttle, the engine will use the primary throttle until the fault is repaired.If a functional throttle is not available, the following conditions will occur:
The engine will default to the limp home speed.
If the engine speed is higher than the limp home speed, the engine will decelerate to the limp home speed.
If the engine speed is lower than the limp home speed, the engine speed will remain at the current speed.
The engine will remain at this speed while the diagnostic code remains active.
All inputs from the faulty throttle are ignored by the ECM until the fault is repaired.
All inputs from the repaired throttle will be ignored by the ECM until the keyswitch has been cycled.The diagnostic codes above relate to an analog sensor. Use this procedure only if the analog sensor uses an output from a variable resistor.The sensor is most likely to be mounted on a throttle pedal. The sensor is attached directly to the throttle assembly. The sensor provides an output voltage to the ECM. The sensor output voltage will vary with the position of the throttle. Foot operated or hand operated throttle assemblies are available.The sensor receives +5 V power from the ECM. The sensor will produce a raw signal voltage that will alter between low idle and high idle.The sensor senses the speed requirement from the throttle position. A second sensor may override this speed requirement from the first sensor. This override will be subject to an input from a secondary throttle or from the SAE J1939 (CAN) data link or from a PTO control.Use the electronic service tool in order to check the input status.
Illustration 1 g03733275
Schematic diagram for the throttle position sensors
Not all connectors are shown. Refer to the Electrical Schematic for the application.
Illustration 2 g02292314
View of the P1 pin locations for the analog throttle position sensors
(16) 5 V supply (throttle 1)
(17) 5 V supply (throttle 2)
(38) Throttle 1 ground
(39) Throttle 2 ground
(60) Throttle 1 position
(61) Throttle 2 position
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position.
B. Check the connectors and the harness for the following faults:
Abrasion
Corrosion
Incorrect attachment
Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Perform a 30 N (6.7 lb) pull test on each of the wires in the harness that are associated with the throttle position sensor. Check the wire connectors at the ECM and at the throttle sensor.
D. Check the harness for abrasions and for pinch points from the sensors back to the ECM.
Damaged wire or connector
Result: A damaged wire or damaged connector was found.
Repair: Repair the damaged wire or the damaged connector. Replace any blown fuses
Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly connected and/or inserted and the harness is free of corrosion, of abrasion or of pinch points.
Proceed to Test Step 2.
2. Check For Active Diagnostic Codes
A. Turn the keyswitch to the ON position.
B. Use the electronic service tool to check for diagnostic codes.
Diagnostic codes
Result: One or more of the diagnostic codes that are listed in Table 1 is active or recently logged.
Proceed to Test Step 5.
Result: There are no active or recently logged diagnostic codes for the analog throttle position sensors.
Proceed to Test Step 3.
3. Check the Throttle Position with the Electronic Service Tool
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position. Do not start the engine.
C. Observe the throttle position reading on the throttle status screens in the electronic service tool.
D. Operate the throttle over the full range of movement.
0 percent at low idle
100 percent at high idle
Result: The throttle output is 0 percent at low idle and 100 percent at high idle.
Proceed to Test Step 4.
Result: The throttle output is not correct.
Repair: Use the electronic service tool to verify that the throttle has been configured correctly before continuing with this procedure. For information on the parameters that can be configured, refer to Troubleshooting, "Configuration Parameters".
If the fault is still present after the throttle has been configured correctly, replace the analog throttle position sensor.
4. Check the Throttle Selection Status with the Electronic Service Tool
A. Check the status of the throttle selection switch (if equipped). Use the electronic service tool in order to check the status of the throttle selection switch.
Note: The control of the engine speed may not switch between throttles unless both throttles are in the low idle position.
The throttle may be overridden by using the SAE J1939 (CAN) data link or a PTO control.
Switch status
Result: If the status of the throttle selection switch is shown in the OFF position, then the throttle 1 has control of the engine speed.
If the throttle selection switch status is shown in the ON position, then the throttle 2 has control of the engine speed.
The throttle selection switch is operating correctly.
Repair: There may be an intermittent fault. Refer to Troubleshooting, "Electrical Connectors - Inspect" in order to identify intermittent faults.
Result: The incorrect throttle is selected.
Repair: Change to the other throttle. There may be a fault with the selector switch input.
Check the connections between the throttle selection switch and P1:62 and battery -. Refer to Troubleshooting, "Electrical Connectors - Inspect". Refer to the Electrical Schematic for the application.
5. Check the Voltage at the Sensor
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the suspect throttle position sensor.
C. Turn the keyswitch to the ON position.
D. Measure the voltage between the 5 V terminal and the sensor ground terminal on the harness connector for the sensor.
4.9 V to 5.1 V
Result: The measured voltage is not within the expected range.
The fault is in the 5 V supply wire or the ground wire between the throttle position sensor and the ECM.
Repair: Check all wiring between the suspect sensor and the ECM. Refer to the Electrical Schematic for the