67888 Mercury CAM FOLLOWER

Table 1
P1 Pin Connections    
Function     Throttle 1     Throttle 2    
+5 Volt DC Supply     41     42    
Sensor Ground     33     34    
Throttle Position Input     54     55    
Illustration 1 g01800755
Schematic of the analog throttle demand sensors
Illustration 2 g01800768
Typical view of the P1 connector pin locations (33) Sensor Ground (GND) (34) Sensor Ground (GND) (41) Sensor supply (5V) (42) Sensor supply (5V) (54) Analog throttle input 1 (55) Analog throttle input 2Test Step 1. Check for Connector Damage
Turn the keyswitch to the OFF position.
Check the connectors and the harness for the following faults: damage, abrasion, corrosion and incorrect attachment.
Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the harness that are associated with the throttle demand sensor. Check the wire connectors at the ECM and at the throttle sensor. The wire connectors are shown in table 1.
Check the screw for the ECM connector for the correct torque of 5.0 N m (44 lb in).Expected Result:The connectors and the harness should be free of the following faults: damage, abrasion, corrosion and incorrect attachment.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 2. Check for Active Diagnostic Codes
Turn the keyswitch to the ON position.
Use the electronic service tool to check for diagnostic codes.Expected Result:RESULT 1 The electronic service tool displays the following active diagnostic codes or recently logged diagnostic codes:
91-3 Throttle Position Sensor voltage above normal
91-4 Throttle Position Sensor voltage below normal
774-3 Secondary Throttle Position Sensor voltage above normal
774-4 Secondary Throttle Position Sensor voltage below normalRESULT 2 The electronic service tool displays no active diagnostic codes:Results:
Result 1 - Proceed to Test Step 3.
Result 2 - Proceed to Test Step 5.Test Step 3. Check the Throttle Position with the Electronic Service Tool
Connect the electronic service tool to the diagnostic connector.
Turn the keyswitch to the ON position. Do not start the engine.
Observe the throttle position reading on the electronic service tool.
Operate the throttle over the full range of movement.Expected Result:The output should increase when the throttle is increased.The output should be between "20 percent" and "27 percent" at the low idle position. The output should be between "80 percent" and "87 percent" at the high idle position.Results:
OK - The sensor is operating correctly. Proceed to Test Step 4.
Not OK - The ECM is not receiving a correct signal from the sensor. Proceed to Test Step 5.Test Step 4. Check the Throttle Selection Status with the Electronic Service Tool
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.Expected 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 may be overridden by using the SAE J1939 (CAN) data link or a PTO control.Results:
OK - The throttle demand switch is operating correctly.Repair: There may be an intermittent fault. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - The wrong throttle is selected. Change to the other throttle. There may be a fault with the selector switch input.Repair: Check the connections between the throttle selection switch and P1:47 and P1:35. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOPTest Step 5. Check the Voltage at the Sensor
Turn the keyswitch to the OFF position.
Install a breakout "T" with 3 terminals to the sensor.
Turn the keyswitch to the ON position.
Measure the voltage between terminal "A" and terminal "B" on the breakout "T".Expected Result:The supply voltage should be between 4.84 Volts DC and 5.16 Volts DC.Results:
OK - The supply voltage is reaching the sensor. Proceed to Test Step 6.
Not OK - The supply voltage is not reaching the sensor.Repair: Refer to Troubleshooting, "5 Volt Sensor Supply Circuit - Test".STOPTest Step 6. Check the Position of the Sensor
Turn the keyswitch to the OFF position.
Install a breakout "T" with 3 terminals to the sensor.
Turn the keyswitch to the ON position.
Measure the voltage between terminal "C" and terminal "B" on the breakout "T".
Observe the voltage while the engine speed control is moved from the minimum to the maximum position.Expected Result:The voltage should vary between 1.5 Volts DC and 4.4 Volts DC when the speed control is moved from the minimum to the maximum position. Results:
OK - The throttle demand sensor is operating correctly. Proceed to Test Step 7.
Not OK - The throttle demand sensor is faulty. Proceed to Test Step 8.Test Step 7. Check the Sensor at the ECM
Turn the keyswitch to the OFF position.
Remove the P1 connector.
Temporarily remove pin P1:54 from the connector.
Reconnect the P1 connector.
Connect the red probe of a multimeter to the removed pin and the black probe of the multimeter to P1:33.
Turn the keyswitch to the ON position.
Use the multimeter to display the output voltage of the sensor while the engine speed control is moved from the minimum position to the maximum position.
Turn the keyswitch to the OFF position.
Remove the P1 connector and reinstall P1:54.
Reconnect the P1 connector.Expected Result:The output from the throttle demand sensor is 0.5 Volts DC or less with the sensor slot in the released position.