855426 Mariner O-RING

Illustration 1 g01823358
Schematic for the PTO inputs for the "Ramp Up/Ramp Down" mode of operation
Table 1
Switch Status    Speed Demand Status    
PTO Enable    PTO Ramp Up    PTO Ramp Down    
Open     Any     Any     Set to the valid engine speed.    
Close     Open     Open     Remain at current desired engine speed.    
Close     Open     Close     Ramp down    
Close     Close     Open     Ramp up    
Close     Close     Close     Invalid latch speed    Placing the PTO Enable switch to the "Enable" position transfers the control of the desired engine speed to the PTO speed control function. The "PTO Ramp Up/Ramp Down Switch" controls the desired engine speed.The "PTO Ramp Up/Ramp Down Switch" is spring loaded to the normally open position. When the switch is held in the "Ramp Up" position, the desired engine speed can be increased up to ten percent above the valid engine speed. When the switch is released, the desired engine speed maintains the set speed.When the "PTO Ramp Up/Ramp Down Switch" is held in the "Ramp Down" position, the desired engine speed can be decreased up to ten percent below the valid engine speed. When the switch is released, the desired engine speed maintains the set speed.If the "PTO Ramp Up" and "PTO Ramp Down" inputs are connected to the −Battery at the same time, the ECM will ignore the inputs. The desired engine speed will not change.If the "PTO Enable Switch" is opened at any speed, the engine will immediately revert to the valid engine speed.Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the engine ECM.
Turn the keyswitch to the OFF position.
Illustration 2 g01167488
ECM connectors (typical example) (1) J1/P1 ECM connectors
Thoroughly inspect connectors (1) and (2). Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01857994
P1 terminals that are associated with the PTO (P1-56) Input from the PTO enable switch (P1-58) Input from the PTO ramp up switch (P1-60) Input for PTO ramp down switch
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuits for the PTO switches.
Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque value.
Check the harness and wiring for abrasions and for pinch points from the battery to the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The connectors and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or the wiring.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.STOPTest Step 2. Check the Inputs from the Switches at the Interface Connector
Disconnect the interface connector.
Refer to Table 2. Connect a voltage test lamp between the input for the suspect switch circuit and terminal 70 (+Battery) on the interface connector.
Restore electrical power to the engine ECM. Turn the keyswitch to the ON position.
Table 2
PTO Switch Inputs on the Interface Connector    
Switch     Terminals    
PTO enable switch     56    
PTO ramp up switch     58    
PTO ramp down switch     60    
Observe the voltage test lamp as you operate the suspect switch.
Turn the keyswitch to the OFF position.
Return all wiring to the original configuration.Expected Result:The voltage test lamp turns on when the switch is closed. The voltage test lamp turns off when the switch is opened.Results:
OK - The voltage test lamp turns on when the switch is closed. The voltage test lamp turns off when the switch is opened. The circuit is operating correctly. Proceed to Test Step 3.
Not OK - The voltage test lamp does not turn on when the switch is closed. Alternatively, the voltage test lamp does not turn off when the switch is opened. There is a problem with the suspect switch and/or the wiring.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.STOPTest Step 3. Check the Inputs from the Switches at the P1 ECM Connector
Disconnect the P1 ECM connector.
Refer to Table 3. Connect a voltage test lamp between the input for the suspect switch circuit and terminal P1-70 (+Battery). Turn the keyswitch to the ON position.
Table 3
PTO Switch Inputs on the Customer Connector    
Switch