System Operation Description:
PTO Shutdown Timer
A programmable parameter for the PTO shutdown timer is provided. This timer will shut down the engine when all of the following conditions are met:
• The PTO shutdown timer has expired.
• The “PTO Shutdown Time” parameter is programmed to at least three minutes.
• The PTO On/Off switch is on and the ECM is in the dedicated PTO mode.
• The engine is not in the cold mode.
During the last 90 seconds of the PTO shutdown timer, the check engine lamp will begin flashing. If the vehicle is equipped with a PTO switch on lamp, the PTO switch on lamp will begin flashing during the last 90 seconds.
If the PTO shutdown timer is activated and the timer stops the engine, the following event code will be generated.
• 71-14 PTO Shutdown
Note: Fuel rates are not monitored while the PTO shutdown timer is active. Shutdown will occur regardless of load. Unlike the idle shutdown timer, the PTO shutdown timer cannot be overridden by using the clutch pedal or the brake pedal.
An additional parameter can be programmed to allow the timer to be reset above a specified engine speed. When the parameter for the “PTO Shutdown Timer Maximum RPM” is programmed to a value below the Top Engine Limit, the timer can be reset by increasing engine rpm above the programmed limit. The timer will stay reset until engine rpm drops below the programmed value. At this point, the timer will begin to count again. The factory default setting of 2120 rpm (Top Engine Limit) disables this feature.
Test Step 1. Verify Activation of the PTO Shutdown Timer
A. Connect the electronic service tool to the data link connector.
B. Access the configuration screen on the electronic service tool. Access the following display screens in order:
• “Service”
• “Configuration”
a. Record the programmed PTO shutdown time.
The PTO shutdown time must be between 3 and 1440 minutes. If the PTO shutdown time is programmed to 0, the timer is disabled.
C. Start the engine. Allow the engine to warm up until the coolant temperature is 38 C (100 F).
Allow the engine to operate at the programmed low idle and turn off any unnecessary accessory devices.
D. Ensure that all unnecessary loads are turned off.
E. Use the following procedure in order to check the operation of the PTO shutdown:
a. Park the vehicle.
b. Ensure that the “PTO Configuration” is programmed to “Cab Switches”, “Remote Switches” or “Remote Throttle”.
c. Ensure that the status for the “PTO On/Off Switch” is “ON”.
d. Observe the status of the “PTO Shutdown Status”.
Note: The “PTO Shutdown Timer Maximum RPM” can be programmed in order to allow the timer to be reset by increasing engine RPM above the programmed limit. Ensure that the accelerator is not being depressed in order to increase rpm beyond the programmed limit.
Expected Result:
Result 1 The status for the “PTO Shutdown Status” indicates “COUNTING”.
Result 2 The ECM is not reading the proper conditions for activation of the timer.
Results:
• Result 1 – The ECM is reading the proper conditions for the activation of the PTO shutdown timer. Proceed to Test Step 2.
• Result 2 – Proceed to Test Step 3.
Test Step 2. Verify the Driver Alert Function of the PTO Shutdown
A. Connect the electronic service tool to the data link connector.
B. Use the following procedure in order to activate the PTO shutdown timer:
a. Access the configuration screen on the electronic service tool. Access the following display screens in order:
• “Service”
• “Configuration”
b. Record the programmed PTO shutdown time.
The PTO shutdown time must be between 3 and 1440 minutes. If the PTO shutdown time is programmed to 0, the timer is disabled.
c. Reprogram the “PTO Shutdown Time” to three minutes for this test.
C. Observe the following items during the 90 second period before the programmed shutdown time:
• Check Engine Lamp
• “PTO Shutdown Status”
• PTO Switch On Lamp
The status should change from “COUNTING” to “DRIVER ALERT” and the check engine lamp and the PTO switch on lamp should flash rapidly, in the last 90 seconds before the scheduled shutdown.
Note: A PTO switch on lamp is an optional feature and the PTO switch on lamp may not be installed.
D. Reprogram the “PTO Shutdown Time” to the value that was recorded earlier for this test.
Expected Result:
Result 1 The driver alert function of the PTO shutdown operates in the manner that is described above.
Result 2 The PTO switch on lamp did not flash.
Result 3 The check engine lamp did not flash.
Results:
• Result 1 – The PTO shutdown timer is operating properly. Clear all diagnostic codes. STOP.
• Result 2 – “PTO Switch On Lamp” did not flash during the driver alert.
Repair: Perform the following diagnostic procedure: Troubleshooting, “PTO Switch ON Lamp Circuit – Test”
STOP.
• Result 3 – The check engine lamp did not flash during the driver alert.
Repair: Perform the following diagnostic
procedure:
Troubleshooting, “Check Engine Lamp Circuit – Test”
STOP.
Test Step 3. Check the State of the Related Conditions When the Vehicle is Parked
A. Check the state of the following related conditions when the vehicle is parked:
a. Ensure that the vehicle speed is 0 km/h (0 mph) on the electronic service tool or the dash display.
b. Ensure that the engine is not in cold mode.
Note: The status screen on the electronic service tool will indicate if the cold mode is active.
c. Ensure that the PTO On/Off switch is on.
Expected Result:
Result 1 Vehicle speed is not indicated as 0 km/h (0 mph).
Result 2 The status screen on the electronic service tool indicates that the engine is in the cold mode.
Result 3 The PTO On/Off switch is not on.
Results:
• Result 1 – Continue by testing the vehicle speed circuit.
Repair: Perform the following diagnostic
procedure: Troubleshooting, “Vehicle Speed Circuit – Test”
STOP.
• Result 2 – The engine must not be in cold mode operation while this test procedure is being performed. Allow the engine to run until the coolant temperature exceeds 38 C (100 F).
Troubleshoot and repair any related conditions.
STOP.
• Result 3 – Continue by testing the circuit for the PTO On/Off switch.
Repair: Perform the following diagnostic
procedure: Troubleshooting, “PTO Switch Circuit – Test”
STOP.
