Circuit Description
The power take off (PTO) accelerator sensor up filter installed detects the PTO control volume. The engine control module (ECM) receives the PTO control volume from the sensor and controls the fuel injection quantity, engine speed during PTO. The PTO accelerator has the following circuits:
| • | A 5-volt reference circuit |
| • | A low reference circuit |
| • | A PTO accelerator sensor signal circuit |
The ECM supplies 5 volts to the PTO accelerator sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The ECM monitors the PTO accelerator sensor signal for voltage outside the normal range of the PTO accelerator sensor. If the ECM detects an excessively high PTO accelerator sensor signal voltage, this DTC will set.
Conditions for Running the DTC
| • | The ignition switch is ON. |
| • | The battery voltage is between 10-16 volts. |
Conditions for Setting the DTC
The ECM detects that the PTO accelerator sensor signal voltage is more than 4.9 volts.
Action Taken When the DTC Sets
| • | The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records. |
| • | The ECM inhibits PTO control. |
Condition for Clearing the DTC
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
| • | If an intermittent condition is suspected, the following may cause an intermittent: |
| - | Poor connections |
| - | A misrouted harness |
| - | Rubbed through wire insulation |
| - | Broken wire inside the insulation |
| • | Inspect for the following conditions: |
| - | Poor connection at ECM--Inspect the harness connectors for the following conditions: |
| • | Backed-out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal to wire connection |
| - | Damaged harness--Inspect the wiring harness for damage. If the harness appears to be OK, observe the PTO Accelerator display on the scan tool while moving the connectors and the wiring harness related to the sensor. A change in the display will indicate the location of the fault. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |
Did the DTC fail this ignition? | -- | Go to Step 3 | Go to Diagnostic Aids | |
3 |
Is the DMM voltage more than the specified value? | 4.5-5.5 V | Go to Step 6 | Go to Step 4 |
4 |
Is the DMM voltage more than the specified value? | 4.5-5.5 V | Go to Step 7 | Go to Step 5 |
5 |
Is the DMM voltage more than the specified value? | 4.5-5.5 V | Go to Step 9 | Go to Step 8 |
6 |
Important: The PTO accelerator sensor may be damaged if the circuit is shorted to a voltage source.
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
7 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
8 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
9 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 |
10 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 |
11 | Replace the PTO. Did you complete the replacement? | -- | Go to Step 13 | -- |
12 |
Important: The new ECM must be programmed. Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data . Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 14 |
14 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
