Diagnostic Test
- CHECK FOR AN ACTIVE DTC NOTE:
Verify that the correct aftermarket PTO assembly was installed. Confirm that the correct wiring and jumpers were used during installation.
NOTE:Repair any correlating TCM communication or TCM PTO Relay Control circuit DTCs before proceeding with this test.
- Turn the ignition on.
- With the scan tool, read DTCs.
Is the DTC active?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- CHECK THE INTEGRATED CENTER STACK (ICS) PTO SWITCH INPUT IN THE PCM
- Start the engine.WARNING:
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.
- With the scan tool, select PCM Data View.
- Press the in cab PTO Switch.
- Review the PTO input data to verify that the status of the PTO Switch.
Is the PTO Switch status displaying True?
Yes
- Go To 3
No
- Go To 4
- Start the engine.
- CHECK THE PTO STATUS IN THE TCM
- With the scan tool, verify that the PTO state value is ACTIVE in the PCM.
- With the scan tool, select TCM Data.
- View the PTO output status to verify that the PTO "ON" value is displaying the correct status.
Is the PTO status displaying "ON"?
Yes
- Go To 8
No
- If all enable conditions are met for system operation and there are no TCM communication or TCM PTO Relay Control circuit DTCs, replace and program the TCM in accordance with the Service Information. Refer to MODULE, TRANSMISSION CONTROL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE INTEGRATED CENTER STACK (ICS) SWITCH INPUT
- Turn the ignition off.
- Disconnect the PCM C1 harness connector.CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
- Connect the (special tool #10436, Adapter, GPEC Diagnostic).
- Start the engine.
- Using the In Cab Power Take Off Switch, turn on the PTO.
- Verify that the (F819) circuit is grounded at the GPEC Adaptor.
Did the ICS In Cab Power Take Off Switch supply ground to the PTO input circuit at the GPEC Adaptor?
Yes
- Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL . Refer to PCM/ECM REPROGRAMMING - GAS .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 5
- CHECK THE ICS IN CAB POWER TAKE OFF SWITCH CIRCUIT FOR AN OPEN
- Turn the ignition off.
- Disconnect the ICS harness connector.CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
- Connect the (special tool #10436, Adapter, GPEC Diagnostic).
- Measure the resistance of the (F819) circuit between the ICS harness connector and the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
- Go To 6
No
- Repair the ICS In Cab Power Take Off Switch Circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE ICS IN CAB POWER TAKE OFF SWITCH CIRCUIT FOR A SHORT TO GROUND
- Check for continuity between ground and the (ICS) In Cab Power Take Off Switch Circuit at the GPEC Adaptor.
Is there continuity between ground and the (ICS) In Cab Power Take Off Switch Circuit?
Yes
- Repair the (ICS) In Cab Power Take Off Switch Circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 7
- Check for continuity between ground and the (ICS) In Cab Power Take Off Switch Circuit at the GPEC Adaptor.
- CHECK THE ICS IN CAB POWER TAKE OFF SWITCH CIRCUIT FOR A SHORT TO VOLTAGE
- Measure the voltage between ground and the (ICS) In Cab Power Take Off Switch Circuit.
Is there any voltage present?
Yes
- Repair the (ICS) In Cab Power Take Off Switch Circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Replace the Integrated Center Stack (ICS) in accordance with the Service Information. Refer to MODULE, INSTRUMENT PANEL CLUSTER .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the voltage between ground and the (ICS) In Cab Power Take Off Switch Circuit.
- CHECK THE POWER TAKE OFF (PTO) RELAY OPERATION
- Turn the ignition off.
- Install a known good Relay.
- Start the engine.
- Attempt to turn on the Power Take Off (PTO).
Does the Power Take Off (PTO) turn on?
Yes
- Replace the Power Take Off (PTO) relay.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 9
- CHECK THE PTO RELAY BATTERY SUPPLY
- Turn the ignition off.
- Remove the PTO Relay.
- Using a 12-volt test light connected to ground, probe the battery supply at the PTO Relay connector (terminal 30 and 86).NOTE:
Compare the brightness to that of a connection across direct battery.
Does the test illuminate brightly?
Yes
- Go To 10
No
- Check for any blown fuses. If the fuses are good, replace the PDC in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE PTO RELAY OUTPUT
- Start the engine.
- Using a 12-volt test light connected to ground, probe the (F605) PTO Relay supply at the Upfitter Connector Aux 2 connector.NOTE:
Compare the brightness to that of a connection across direct battery.
Does the test illuminate brightly?
Yes
- Verify that the correct Upfitter PTO assembly was installed. Confirm that the correct wiring and jumpers were used during installation.
No
- Repair the (P605) circuit for an open.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .