Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
DTC Descriptor
DTC P254D: Power Take-off (PTO) Engine Speed Selector Sensor Circuit High VoltageDiagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
PTO Throttle Sensor 5-Volt Reference | -- | -- | -- | -- | -- |
PTO Throttle Sensor Signal | -- | -- | -- | P254D | -- |
PTO Throttle Sensor GND | -- | -- | P254D | -- | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Ignition ON Parameter Normal Range: PTO Remote Throttle Sensor -- Depressed at 100% equals 5V, Released at 0% is ON | |||
PTO Throttle Sensor 5-Volt Reference | -- | -- | -- |
PTO Throttle Sensor Signal | -- | 5 V | -- |
PTO Throttle Sensor Low Reference | -- | 5 V | -- |
Circuit/System Description
The power take off (PTO) throttle sensor, upfitter installed, detects the PTO control throttle angle. The engine control module (ECM) receives the PTO control throttle angle from the throttle sensor and controls the fuel injection quantity (engine speed) during PTO.
The ECM supplies 5 volts to the PTO throttle sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The ECM monitors the PTO throttle sensor signal for voltage outside the normal range of the PTO throttle sensor.
Conditions for Running the DTC
| • | DTCs P0642 and P0643 are not set. |
| • | The battery voltage is between 10-16 volts. |
| • | The ignition switch is ON. |
Conditions for Setting the DTC
The ECM detects that the PTO throttle sensor signal voltage is more than 4.9 volts for longer than 1 second.
Action Taken When the DTC Sets
DTC P254D is a Type D DTC.
Conditions for Clearing the DTC
DTC P254D is a Type D DTC.
Diagnostic Aids
| • | An incorrectly installed PTO throttle sensor will cause this DTC to set. |
| • | An incorrectly programmed option will cause this DTC to set. |
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
Verify the integrity of the PTO throttle sensor by inspecting for the following conditions:
| • | Damaged components |
| • | Loose or improper installation |
Circuit/System Testing
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- With the ignition OFF, disconnect the harness connector at the PTO throttle sensor. Allow at least 60 seconds for the ECM to power down. Test for less than 3 ohms of resistance between the applicable low reference circuit and ground.
- With the ignition ON, test for 4.8-5.2 volts between the applicable PTO throttle sensor 5-volt reference circuit and ground.
- Install a 3A fused jumper wire between the applicable signal circuit and the applicable 5-volt reference circuit. Verify that the scan tool PTO throttle sensor parameter is greater than 0.2 volt.
| ⇒ | If greater than 3 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module. |
| ⇒ | If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module. |
| ⇒ | If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module. |
| ⇒ | If less than 0.2 volt, test the applicable signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module. |
| ⇒ | If greater than 0.2 volt, replace the PTO throttle assembly. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | PTO Throttle Sensor Replacement |
| • | Control Module References for ECM replacement, setup, and programming |
