Power Take-Off System GMC Sierra 2500

Scheme 1

Scheme 2

Scheme 3

Diagnostic Code Index

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

1. The PTOM detects that the requested RPM and the actual engine RPM do not match.
2. The above condition is present for greater than a predetermined time threshold.

Action Taken When the DTC Sets

The PTOM stores the DTC information into memory when this diagnostic runs and fails.

Conditions for Clearing the DTC

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 100 consecutive warm-up cycles, if failure is no longer present.

Diagnostic Aids

1. When not in mobile PTO mode, heavy engine load may cause this code to be set.
2. Use a scan tool to observe the PTO inhibit and disengage history.

Reference Information

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Engine ON, press 1 on the PTO switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds. Press RES + to increase the engine speed and SET - to decrease the engine speed accordingly.
2. Engine ON, clear codes in the PTOM and then engage PTO. Verify that DTC P061C does not reset as current in the PTOM. If the specified code sets as current, replace the ECM. Do not replace the PTOM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

The engine is running.

The PTO module detects that the 5-volt reference of the PTO switch is above or below a predetermined voltage threshold.

1. The malfunction indicator lamp (MIL) will not illuminate.
2. The PTO module records the operating conditions at the time the diagnostic fails. The PTO module stores this information in the Snapshot Records.

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 100 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.

Using the Snapshot Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Engine ON, press 1 on the PTO switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds.
2. Disengage PTO. If equipped, use the remote switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds.

Circuit/System Testing

1. Ignition OFF. Disconnect the harness connector at the PTO switch.
2. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PTO module. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the PTO module.
3. Clear all DTCs. Verify that P0641 sets as current in the PTO module. If the specified code does not set as current, test or replace the PTO switch.
4. Ignition OFF, connect the harness connector at the PTO switch.
5. Disconnect the harness connector at X124.
6. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal E at the female side of the connector and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PTO module. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the PTO module.
7. Ignition ON, test for 0 volts between the 5-volt reference circuit terminal E at the male side of the connector and ground. If greater than the specified value, test the 5-volt reference circuit between X124 and the upfitted remote PTO switch assembly for a short to voltage. If the circuit tests normal, test or replace the upfitted remote PTO switch assembly.
8. Ignition OFF, test for infinite resistance between the 5-volt reference circuit terminal E at the male side of the connector and ground. If less than the specified value, test the 5-volt reference circuit for a short to ground. If the circuit tests normal, test or replace the upfitted remote PTO switch assembly.
9. If all circuits test normal, replace the PTO module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Take-Off Switch Replacement»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
2. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PTO module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

The engine is running.

The PTO module detects that the 5-volt reference of the PTO remote is above or below a predetermined voltage threshold.

1. The malfunction indicator lamp (MIL) will not illuminate.
2. The PTO module records the operating conditions at the time the diagnostic fails. The PTO module stores this information in the Snapshot Records.

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 100 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.

Using the Snapshot Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition OFF, use the remote switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds.

1. Ignition OFF, disconnect the harness connector at X124.
2. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal E at the female side of the connector and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PTO module. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the PTO module.
3. Ignition ON, test for 0 volts between the 5-volt reference circuit terminal E at the male side of the connector and ground. If greater than the specified value, test the 5-volt reference circuit between X124 and the upfitted remote PTO switch assembly for a short to voltage. If the circuit tests normal, test or replace the upfitted remote PTO switch assembly.
4. Ignition OFF, test for infinite resistance between the 5-volt reference circuit terminal E at the male side of the connector and ground. If less than the specified value, test the 5-volt reference circuit for a short to ground. If the circuit tests normal, test or replace the upfitted remote PTO switch assembly.
5. If all circuits test normal, replace the PTO module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Take-Off Switch Replacement»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
2. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PTO module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

The engine is running and PTO is engaged.

1. The PTOM detects a signal mismatch between the remote engine shut off signal and the PTO engine shutdown signal.
2. The above condition is present for greater than a predetermined time threshold.

1. The PTOM stores the DTC information into memory when this diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. PTO becomes disabled until the next ignition cycle.
4. The remote engine start function defaults back to disabled.

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 100 consecutive warm-up cycles, if failure is no longer present.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

With PTO enabled, use a scan tool to shutdown the engine using the Engine Shutdown special function in the PTO module. The engine should shutdown.

1. Engine ON, verify that the PTO Remote Switch Status parameter reads PTO On when the upfitted PTO remote engine switch is commanded ON and reads PTO Off when the upfitted PTO remote engine shutdown switch is commanded OFF. If the parameter does not read the specified values accordingly, test the engine shut off signal circuit terminal 31 for a short to voltage, short to ground or an open/high resistance. If the circuit tests normal, test or replace the upfitted remote engine shutdown switch.
2. If the DTC still sets as current, replace the PTO module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PTO module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a GMLAN serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

The PTO module becomes active.

P251A

1. The PTOM detects a high voltage signal on one or more of the in-cab PTO switch circuits: SET -, RES +, 1 or 0.
2. The above condition is present for greater than a predetermined time threshold.
3. This code moves to history after 90 seconds.

P251E or P251F

1. The PTOM detects that the PTO engine shutdown signal circuit is above or below a predetermined voltage threshold.
2. The above condition is present for greater than a predetermined time threshold.

1. The PTOM stores the DTC information into memory when this diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. PTO becomes disabled.

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 40 consecutive warm-up cycles, if failure is no longer present.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

P251A

1. Ignition ON, verify that P0641 is not set as current in the PTO module. If the specified DTC is set as current, refer to «DTC P0641»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system) .
2. Engine ON, press 1 on the PTO switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds. Press RES + to increase the engine speed and SET - to decrease the engine speed accordingly. Press 0 to disengage PTO and to return the engine speed back to normal idle.

P251E or P251F

1. Engine ON, with PTO enabled using the in-cab PTO switch, momentarily press the 0 switch. The engine RPM should return to normal idle speed.
2. With PTO enabled, momentarily press the remote engine shutdown switch. The engine RPM should return to normal idle speed and the engine will shutdown.

P251A

1. Ignition OFF, disconnect the harness connector at the PTO module.
2. Ignition OFF, disconnect the harness connector at the in-cab PTO switch.
3. Ignition OFF, test for infinite resistance between the harness connector at the PTO switch mode select A signal circuit terminal 2 and ground. If less than the specified value, test the mode select A signal circuit for a short to ground.
4. Ignition OFF, test for less than 1.0 ohm of resistance in the mode select A signal circuit between the PTO switch connector terminal 2 and the PTO module connector terminal 26. If greater than the specified range, test the mode select A signal circuit for an open/high resistance.
5. Ignition OFF, test for infinite resistance between the harness connector at the PTO switch mode select B signal circuit terminal 9 and ground. If less than the specified value, test the mode select B signal circuit for a short to ground.
6. Ignition OFF, test for less than 1.0 ohm of resistance in the mode select B signal circuit between the PTO switch connector terminal 9 and the PTO module connector terminal 11. If greater than the specified range, test the mode select B signal circuit for an open/high resistance.
7. Ignition OFF, test for infinite resistance between the harness connector at the PTO switch mode select C signal circuit terminal 4 and ground. If less than the specified value, test the mode select C signal circuit for a short to ground.
8. Ignition OFF, test for less than 1.0 ohm of resistance in the mode select C signal circuit between the PTO switch connector terminal 4 and the PTO module connector terminal 12. If greater than the specified range, test the mode select C signal circuit for an open/high resistance.
9. If all circuits test normal, replace the PTO switch.

P251E or P251F

1. Ignition OFF, disconnect the harness connector at the PTOM.
2. Ignition ON, test for 0 volts between the PTO engine shutdown signal circuit terminal 33 and ground. If greater than the specified value, test the PTO engine shutdown signal circuit for a short to voltage. If the circuit test normal, replace the ECM.
3. Ignition OFF, disconnect the harness connector X1 at the ECM.
4. Ignition OFF, test for infinite resistance between the PTO engine shutdown signal circuit X1 terminal 84 and ground. If less than the specified range, test the PTO engine shutdown signal circuit for a short to ground.
5. Ignition OFF, test for less than 1.0 ohm on the PTO engine shutdown signal circuit between the PTO connector terminal 33 and the ECM connector X1 terminal 84. If greater than the specified range, test the PTO engine shutdown signal circuit for an open/high resistance.
6. Ignition OFF, test for less than 1.0 ohm on the PTO engine shutdown signal circuit between the PTO connector terminals 33 and 31.
7. If greater than the specified range, test the PTO engine shutdown signal circuit for an open/high resistance. If the circuit tests normal, test or replace the upfitter remote switch assembly.
8. If all circuits test normal, replace the PTOM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Take-Off Switch Replacement»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
2. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PTO module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a GMLAN serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

The ignition is ON and PTO is engaged.

1. The PTOM detects a high voltage signal at the PTO engage signal circuit.
2. The above condition is present continuously for greater than a predetermined time threshold.

1. The PTOM stores the DTC information into memory when this diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. PTO becomes disabled until the next ignition cycle.

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 40 consecutive warm-up cycles, if failure is no longer present.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Engine ON, press 1 on the PTO switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds. Press RES + to increase the engine speed and SET - to decrease the engine speed accordingly.

1. Ignition OFF, disconnect the harness connector at the PTO module.
2. Ignition OFF, disconnect the PTO relay.
3. Ignition ON, verify that a test lamp does not illuminate between the PTO engage signal circuit terminal 46 and ground. If the test lamp illuminates, test the PTO engage signal circuit for a short to voltage. If the circuit tests normal, test or replace the upfitted remote engine PTO switch assembly.
4. Ignition OFF, connect the harness connector at the PTO module.
5. Ignition ON, verify that a test lamp does not illuminate between the PTO engage signal circuit terminal 46 and ground. If the test lamp illuminates, replace the PTO module.
6. If all circuits test normal, test or replace the PTO relay.

Component Testing

PTO Relay (If supported by the PTO upfitter wiring)

1. Ignition OFF, disconnect the PTO relay.
2. Test for approximately 50-200 ohms of resistance between terminals H and J on the upfitter wiring side of the upfitter PTO connector. If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals: F and J F and H F and K K and J If less than infinite resistance, replace the PTO relay.
4. Install a 15-amp fused jumper wire between relay terminal J and 12 volts. Install a jumper wire between relay terminal H and ground. Test for less than 2.0 ohms of resistance between the relay switch terminals. If greater than 2.0 ohms, replace the PTO relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PTO module or TCM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a GMLAN serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

The PTO module becomes active.

1. The PTOM detects a valid stuck signal on one or more of the PTO switch circuits: SET -, RES +, 1 or 0.
2. The above condition is present for greater than 90 seconds.

1. The PTOM stores the DTC information into memory when this diagnostic runs and fails.
2. PTO becomes disabled until the next ignition cycle.

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 40 consecutive warm-up cycles, if failure is no longer present.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Engine ON, press 1 on the PTO switch to engage PTO. The PTO indicator will illuminate. The engine RPM should increase to the programmed PTO standby speed (between 800 RPM-1500 RPM) within a few seconds. Press RES + to increase the engine speed and SET - to decrease the engine speed accordingly. Press 0 to disengage PTO and to return the engine speed back to normal idle.

1. Ignition OFF, disconnect the harness connector at the in-cab PTO switch.
2. Ignition ON, test for 4.5 to 5.2 volts on the vehicle harness connector between the following terminals: 2 and ground 9 and ground 4 and ground 1 and ground If less than the specified range, disconnect the harness connector at the PTO module and test the failed signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PTO switch. If greater than the specified range, test the failed signal circuit for a short to voltage. If the circuit tests normal, test or replace the PTO module.
3. Ignition OFF, test for less than 0.5 ohm of resistance between the ground circuit terminal 5 and ground. If greater than the specified value, test the ground circuit terminal 5 for a high resistance. If the circuit tests normal, replace the PTO module.
4. If the circuits test normal, replace the PTO switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Take-Off Switch Replacement»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
2. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PTO module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a GMLAN serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

The engine is running.

The PTOM detects a fault on the PTO relay coil control circuit that is above or below a predetermined voltage threshold.

1. The malfunction indicator lamp (MIL) will not illuminate.
2. The PTOM records the operating conditions at the time the diagnostic fails. The PTOM stores this information in the Failure Records.

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, verify that DTC P0562, P0563 in the ECM and/or B1325 are not set as current. If one of the specified DTCs is found as current, repair those DTCs first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
2. Verify that DTC C0899 or C0900 are not current in the scan tool. If the any of the specified DTCs are current, repair those DTCs first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .

1. Ignition OFF, disconnect the PTO relay.
2. Igniton ON, test for 11 volts or greater between the PTO relay supply voltage circuit terminal 86 and ground. If less than the specified voltage, test the PTO relay supply voltage circuit for a short to ground or an open/high resistance.
3. Ignition OFF, disconnect the harness connector at the PTO module.
4. Ignition ON, test for 0 volts between the PTO relay coil control circuit terminal 28 and ground. If greater than the specified value, test the PTO relay control circuit for a short to voltage.
5. Ignition OFF, connect the PTO relay.
6. Ignition ON, test for 11 volts or greater between the PTO relay coil control circuit terminal 28 and ground. If less than the specified voltage, test the PTO relay coil control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the PTO relay.
7. If all circuits test normal, replace the PTO module.

PTO Relay

1. Ignition OFF, disconnect the PTO relay.
2. Test for 60-180 ohms of resistance between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals: 30 and 86 30 and 87 30 and 85 85 and 87 If less than infinite resistance, replace the PTO relay.
4. Install a 20-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2.0 ohms of resistance between terminals 30 and 87. If greater than 2.0 ohms, replace the PTO relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PTO module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a GMLAN serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

The ignition is ON.

1. The PTOM detects an invalid voltage signal at the PTO switch indicator control circuit.
2. The above condition is present continuously for greater than a predetermined time threshold.

1. The ECM stores the DTC information into memory when this diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.
4. PTO becomes disabled until the next ignition cycle.

1. A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.

Schematic Reference

1. «Power Take-Off (PTO) Schematics»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
2. «Interior Lights Dimming Schematics»(/gmc/sierra-2500/2012-2012/remont/exterior-lights/#lighting-system)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Verify that the interior backlighting system operates normal. Refer to «Interior Lighting Systems Description and Operation»(/gmc/sierra-2500/2012-2012/remont/exterior-lights/#lighting-system) .
2. Engine ON, press 1 on the PTO switch to engage PTO. The PTO LED indicator will turn on blinking at a 0.25 second interval rate when the PTO relay is energized. The indicator turns on solid once the PTO load feedback signal confirms the load has been engaged or after 3 seconds if load feedback is not utilized by the PTO system.

1. Ignition OFF, disconnect the harness connector at the PTO switch.
2. Connect a test lamp between LED dimming supply circuit terminal 7 and ground.
3. Ignition OFF, turn the headlamps ON and OFF. The test lamp should turn ON and OFF accordingly with the headlamp switch. If the test lamp is always ON, test the LED dimming supply circuit for a short to voltage. If the test lamp is always OFF, test the LED dimming supply circuit for a short to ground or an open/high resistance.
4. Ignition ON, verify that a test lamp does not illuminate between the PTO switch indicator control circuit terminal 8 and ground. If the test lamp illuminates, test the PTO switch indicator control circuit for a short to voltage. If the circuit tests normal, test or replace the PTO module.
5. Ignition OFF, PTO OFF, verify that a test lamp does not illuminate between the PTO switch indicator control circuit and B+. If the test lamp illuminates, test the PTO switch indicator control circuit for a short to ground. If the circuit tests normal, test or replace the PTO module.
6. Ignition OFF, disconnect the harness connector at the PTO module.
7. Ignition OFF, test for less than 1.0 ohm of resistance on the PTO switch indicator control circuit between the PTO switch terminal 8 and the PTO module terminal 9. If greater than the specified range, test the PTO switch indicator control circuit for an open/high resistance.
8. If all circuits test normal, test or replace the PTO switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Take-Off Switch Replacement»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
2. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PTO module replacement, setup, and programming

Symptoms - Power Take-Off (PTO)

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) , before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to «Power Take-Off (PTO) Description and Operation»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system__power-take-off-pto-description-and-operation) .

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Power Take-Off system. Refer to «Checking Aftermarket Accessories»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

1. «Power Take-Off (PTO) Does Not Engage»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
2. «Engine RPM Does Not Increase with Power Take-Off Engaged»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
3. «Power Take-Off (PTO) Indicator Inoperative»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a GMLAN serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Engine ON, observe the PTO In Cab Switch parameter with a scan tool. Press 1 on the PTO switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds. Press 0 to disengage PTO and to return the engine speed back to normal idle. The PTO In Cab Switch parameter should change accordingly with the depressed switch.
2. Engine OFF, key out of ignition, observe the PTO Remote Switch Status with a scan tool. Enable PTO using the upfitted remote switch assembly (if equipped). The engine RPM should increase to the default engine speed within a few seconds. Use the upfitted remote switch assembly to disengage PTO and the engine should shut down. The PTO Remote Switch Status parameter should change accordingly with the depressed remote switch.

PTO In Cab Switch

1. Ignition OFF, disconnect the harness connector at the PTO module.
2. Ignition ON, test for 11 volts or greater between the B+ circuit terminal 32 and ground. If less than the specified voltage, test the B+ circuit for a short to ground or an open/high resistance.
3. Ignition OFF, connect the harness connector at the PTO module.
4. Ignition OFF, disconnect the harness connector at the PTO switch.
5. Ignition ON, test for 4.8-5.2 volts between the 5V reference circuit terminal 1 and ground. If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PTO module. If greater than the specified range, test the 5V reference circuit for a short to voltage. If a short to voltage is found and repaired, replace the PTO switch. If the circuit tests normal, replace the PTO module and the PTO switch.
6. Connect the harness connector at the PTO switch.
7. Engine ON, observe the PTO In Cab Switch parameter with a scan tool. Verify that the PTO In Cab Switch parameter matches each depressed switch: 1, 0, RES +, SET -. If any one of the switches do not match accordingly with the scan tool parameter, replace the PTO switch.
8. If all circuits test normal, replace the PTO module.

Upfitted Remote Switch Assembly

1. Ignition OFF, disconnect the harness connector at the PTO module.
2. Ignition ON, test for 11 volts or greater between the B+ circuit terminal 32 and ground. If less than the specified voltage, test the B+ circuit for a short to ground or an open/high resistance.
3. Ignition OFF, connect the harness connector at the PTO module.
4. Ignition OFF, disconnect the harness connector X124.
5. Ignition ON, test for 4.8-5.2 volts between the 5V reference circuit terminal E and ground. If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PTO module. If greater than the specified range, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the PTO module.
6. Connect the harness connector X124.
7. Engage PTO using the upfitted remote switch assembly. Observe the PTO Remote Switch Status parameter with a scan tool. Verify that the PTO Remote Switch Status parameter matches each depressed switch. If any one of the switches do not match accordingly with the scan tool parameter or if PTO does not engage, replace the upfitted remote switch assembly.
8. If all circuits test normal, replace the PTO module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PTO module replacement, setup, and programming
2. «Power Take-Off Switch Replacement»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. When PTO is engaged, the power take-off module (PTOM) sends a GMLAN serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Engine ON, observe the PTO In Cab Switch parameter with a scan tool. Press 1 on the PTO switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds. Press 0 to disengage PTO and to return the engine speed back to normal idle. The PTO In Cab Switch parameter should change accordingly with the depressed switch. The ECM must be programmed to the same PTO mode (Preset, Variable, Mobil) as the PTOM in order to execute the request for increased RPM. The DIC may display "Speed Range" if this is incorrect.
2. Engine OFF, key out of ignition, observe the PTO Remote Switch Status with a scan tool. Enable PTO using the upfitted remote switch assembly (if equipped). The engine RPM should increase to the default engine speed within a few seconds. Use the upfitted remote switch assembly to disengage PTO and the engine should shut down. The PTO Remote Switch Status parameter should change accordingly with the depressed remote switch.

PTO In Cab Switch

1. Engine ON, engage PTO. Observe the PTO In Cab Switch parameter with a scan tool. Verify that the PTO In Cab Switch parameter matches each depressed switch: RES +, SET -. If any one of the switches do not match accordingly with the scan too parameter, replace the PTO switch.
2. If all circuits test normal, replace the PTO module.

Upfitted Remote Switch Assembly

1. Engage PTO using the upfitted remote switch assembly. Observe the PTO Remote Switch Status parameter with a scan tool. Verify that the PTO Remote Switch Status parameter matches each depressed switch for increasing and decreasing engine RPM. If any one of the switches do not match accordingly with the scan tool parameter, replace the upfitted remote switch assembly.
2. If all circuits test normal, replace the PTO module.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Power Take-Off Switch Replacement»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)
2. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PTO module replacement, programming and setup

1. Perform the «Diagnostic System Check - Vehicle»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/gmc/sierra-2500/2012-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO using either the PTO switch or PTO remote, the engine RPM will increase to a default standby speed. The engine control module (ECM) converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. When PTO is engaged, the power take-off module (PTOM) sends a GMLAN serial data message to the ECM requesting engine speeds, in accordance with the depressed switches from the PTO switch or remote.

Schematic Reference

Power Take-Off (PTO) Schematics

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/gmc/sierra-2500/2012-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Verify that the interior backlighting system operate normally. Refer to «Interior Lighting Systems Description and Operation»(/gmc/sierra-2500/2012-2012/remont/exterior-lights/#lighting-system) .
2. Ignition ON, install a scan tool and verify that DTC P260D is not set as current. If the specified DTC is set as current, refer to «DTC P260D»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system) .
3. Ignition ON, with the scan tool, command the PTO Indicator ON and OFF. The PTO indicator in the PTO switch should illuminate ON and OFF accordingly. If the indicator is illuminates ON and OFF accordingly, replace the PTO module.

1. Ignition OFF, disconnect the harness connector at the PTO switch.
2. Connect a test lamp between LED dimming supply circuit terminal 7 and ground.
3. Ignition OFF, turn the headlamps ON and OFF. The test lamp should turn ON and OFF accordingly with the headlamp switch. If the test lamp is always ON, test the LED dimming supply circuit for a short to voltage. If the test lamp is always OFF, test the LED dimming supply circuit for a short to ground or an open/high resistance.
4. Ignition ON, verify that a test lamp does not illuminate between the PTO switch indicator control circuit terminal 8 and ground. If the test lamp illuminates, test the PTO switch indicator control circuit for a short to voltage. If the circuit tests normal, test or replace the PTO module.
5. Ignition OFF, PTO OFF, verify that a test lamp does not illuminate between the PTO switch indicator control circuit and B+. If the test lamp illuminates, test the PTO switch indicator control circuit for a short to ground. If the circuit tests normal, test or replace the PTO module.
6. Ignition OFF, disconnect the harness connector at the PTO module.
7. Ignition OFF, test for less than 1.0 ohm of resistance on the PTO switch indicator control circuit between the PTO switch terminal 8 and the PTO module terminal 9. If greater than the specified range, test the PTO switch indicator control circuit for an open/high resistance.
8. If all circuits test normal, test or replace the PTO switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/gmc/sierra-2500/2012-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for PTO module replacement, setup, and programming.
2. «Power Take-Off Switch Replacement»(/gmc/sierra-2500/2012-2012/remont/power-takeoff/#power-take-off-system)

Scheme 4

Power Take-Off Switch Replacement

Scheme 5

Engine Speed Power Take-Off Control Module Replacement

Power Take-Off (PTO) Description and Operation

The power take-off (PTO) is an upfitter integrated system that allows the user to create an auxiliary power source. The PTO system specifically controls engine speed to values higher than normal base idle, PTO load relay engagement, and remote starting and shutdown of the engine. When the operator requests PTO, the PTO switch will be turned ON and the engine RPM will go to a default standby speed.

The PTO system utilizes the following

Factory Installed PTO Components

1. The transmission driven PTO gear
2. The in-cab PTO switch
3. The power take off module (PTOM)
4. The remote PTO upfitter connector
5. Revised underbody structure and floor covering

Factory Installed PTO Components

In-cab PTO Switch

The PTO switch is mounted in the right side of the center instrument panel. The PTO switch is a four position rocker type: 1, 0, SET - and RES +. When the PTO 1 position is depressed, the PTO relay will be energized by the PTOM. A PTO LED indicator is integrated with the switch. The indicator will illuminate, flashing at a 0.25 second interval rate when the PTO relay is energized. The indicator illuminates solid once the PTO load feedback signal confirms the load has been engaged or after 3 seconds if load feedback is not utilized by the PTO system. The indicator will flash at a 1 second interval rate when PTO memory speed is retained. Depressing the 0 position turns the PTO system off. The PTO LED will turn off once engine speed reaches base engine idle, at which time the PTO relay is de-energized.

Transmission Driven PTO Gear

The Allison LCT-1000 transmission provides the PTO gear with the vehicles PTO option package. If the vehicle option package does not include PTO, then the PTO gear will not be included in the transmission.

The illumination of the background text of the PTO switch is provided through the dimming circuit controlled by the BCM.

Power Take-Off Module (PTOM)

The PTO electrical system is integrated around a central PTO control module. The PTO Module (PTOM) provides the following key functions

1. Processes PTO operator switch inputs and translates these inputs into an engine speed request to the ECM
2. Controls the engagement of the PTO load relay
3. Process requests to the BCM and ECM to start and shutdown the engine
4. Requests the IPC to display on the DIC the actions the driver must take to enable PTO
5. Requests the ECM to command an engine shutdown and engine shutdown horn warning for critical engine and transition conditions (stationary remote PTO only).

The PTOM constantly looks at the information from various sensors and other inputs, and controls the systems that affect vehicle performance. If any of the PTO engage conditions for the specific operating mode are no longer valid, the engine controller will exit out of PTO mode.

Remote PTO Upfitter Connector

The PTO upfitter connector provides access to all remote PTO functions. The connector is located on the right-hand outside frame rail, underneath the passenger side door. Electrical connections to the following components are provided by this connector. The upfitter connector pin circuits (other than battery, ignition and ground) are disabled as the vehicle is received from the factory. The PTO module must be reprogrammed by the upfitter or dealer to enable the following circuits

1. Remote PTO Arming
2. Remote PTO Enable
3. Remote PTO Set
4. Remote Accelerator
5. Remote Engine Shutdown

Other Vehicle Modules

The PTO system also utilizes the following vehicle modules, which communicate over the serial data system

1. The body control module (BCM)
2. The electronic brake control module (EBCM)
3. The engine control module (ECM)
4. The instrument panel cluster (IPC)
5. The transmission control module (TCM)

Body Control Module (BCM)

The BCM maintains the PTO factory default mode, unless it is reprogrammed with a scan tool to change the PTO configuration mode from factory preset to either stationary variable or mobile variable. The BCM also controls the remote start function. The BCM also controls the illumination of the background text of the PTO switch through the dimming circuit.

Electronic Brake Control Module

The EBCM monitors the vehicle speed. The PTOM receives the status of the vehicle speed from the EBCM via serial data messages.

Engine Control Module (ECM)

The ECM controls the engine speed and the engine starting based on messages from the PTOM through serial data. The ECM also provides PTO specific engine information to the PTOM through serial data messages.

Instrument Panel Cluster (IPC)

The driver information center (DIC) of the IPC displays actions the driver must take in order to engage PTO. If the PTO will not engage, one or more of the following DIC messages may appear on the instrument panel cluster (IPC)

Transmission Control Module (TCM)

The TCM adjusts shift patterns to minimize shift during PTO operation. The TCM also provides transmission gear states and temperature conditions to the PTOM via serial data messages.

PTO Enable Conditions

Stationary PTO

The following conditions must be met in order to engage stationary PTO

1. The engine must be running.
2. The vehicle cannot be moving and the parking brake must be set.
3. The shift lever must be in PARK (P) or NEUTRAL (N).
4. The brake pedal must not be pressed.

In-cab PTO operation: Press and release the 1 position on the PTO switch. The PTO LED will flash fast until the PTO load becomes engaged. When the load becomes engaged, the LED will stop flashing and stay illuminated. The SET - and RES + switch positions can then be used to establish the desired PTO operating speed.

Remote PTO operation: Press and release the remote PTO arming switch, then within five seconds, move the PTO enabled switch from OFF to ON. The remote LED will illuminate when the PTO load is engaged. The PTO remote SET switch can then be used to establish the desired PTO operating speed. These switches are accessed through the PTO upfitter connector, located under the passenger side door.

Mobile PTO

The following conditions must be met prior to engaging mobile PTO

1. The engine must be running.
2. The vehicle speed must be less than the PTO top vehicle speed limit. The default setting is 80 km/h (50 mph). This limit can be adjusted.
3. The shift lever may be in any position.
4. The brake must be pressed and then released. The brake must then remain released.
5. Cruise control cannot be active.
6. Engine speed must be less than the maximum allowed PTO engage speed of 1800 RPM.
7. Press and release the 1 position on the PTO switch. The PTO LED will flash fast until the PTO load becomes engaged. When the load becomes engaged, the LED will stop flashing and stay illuminated. The SET - and RES + switch positions can then be used to establish the desired PTO operating speed.

PTO Disengage Conditions

Stationary PTO

The stationary PTO mode will disengage if any of the following conditions are detected by the vehicle modules

1. Vehicle movement
2. The park brake is released
3. The transmission is shifted from PARK (P) or NEUTRAL (N) to DRIVE (D) or REVERSE (R).
4. The PTO load becomes disengaged
5. Press and release the 0 button on the PTO in-cab switch
6. Move the speed enable switch to the OFF position on the remote PTO controls
7. Press the remote engine shutdown switch (stationary remote PTO only)

Mobile PTO

The mobile PTO mode will also disengage if the following conditions are detected by the vehicle modules

1. Press the brake pedal
2. Vehicle speed exceeds 80 km/h (50 mph)
3. Engine speed exceeds the maximum allowed PTO operating speed of 2100 RPM
4. The PTO load becomes disengaged
5. Press and release the 0 button on the PTO in-cab switch

The PTO control system will attempt to limit accelerator pedal and PTO switch input as the vehicle approaches the above operational limits. There are some vehicle conditions, such as down hill acceleration, which may cause vehicle speed or engine speed limits to be exceeded. Under those conditions, PTO is disengaged.

Modes of Operation

Preset PTO Mode

Preset PTO can only be used when the vehicle is not moving. The engine speed is initially set to a standby engine speed of 800 RPM. This provides an initial start-up engine speed to match the engagement of the PTO load. The PTO standby engine speed can be reprogrammed to higher speeds.

Choose one of two presets by pressing and releasing the PTO In-cab or remote PTO SET in the SET - or RES + switch positions

1. Speed 1: Pressing the SET - position results in a preset speed of 1250 RPM
2. Speed 2: Pressing the RES + position results in a preset speed of 1700 RPM

Pressing the 0 switch position on the PTO in-cab switch or moving the remote PTO enable switch to OFF results in the return of the engine speed back to normal idle. The PTO load relay is also disengaged.

Maximum PTO Operating Speed: During PTO operation, the accelerator pedal can be pressed to adjust the engine speed. To protect the PTO from overspeed, the PTO system will disengage when the engine speed exceeds 2100 RPM.

The Stationary PTO Mode provides both in-cab and remote controls. The in-cab controls are enabled as the factory preset. The remote controls are disabled. This factory preset configuration can be reprogrammed to enable the remote controls, and disable the in-cab PTO controls.

PTO - Variable Mode

In this mode, the vehicle can be programmed for stationary or mobile operation.

The variable PTO mode controls engine speed and PTO load engagement is selected by either the PTO in-cab or remote switches. Engine speed selection is variable between base engine idle speed and a maximum of 2100 RPM.

In the mobile PTO mode, the vehicle will operate at a vehicle speed resulting from the current PTO engine speed request and current transmission gear range selected.

Vehicle speed stability is greatly improved by shifting into the transmission manual mode because upshifts are limited. This reduces the maximum vehicle speed while allowing high engine speed operation. Therefore, low vehicle speed operation, 16-40 km/h (10-25 mph) and high PTO engine speed 1500-2000 RPM can be achieved in the manual mode 1 and 2 transmission ranges.

In-cab PTO Switch Operation

1. 1: This is the PTO switch On position. Press and release the 1 switch to engage PTO. PTO will increase the engine speed to the factory preset engine speed. The initial standby speed can be adjusted by holding the accelerator to the desired engine speed, then pressing and releasing the 1 switch. The current engine speed will become the new standby speed. This adjustment can only be done once at the initial engagement of PTO, and the initial standby speed adjustment must be between the engine base idle speed and the maximum PTO engage speed.
2. 0: This is the PTO switch Off position. Press and release the 0 switch to disengage PTO. The engine speed will be return to the base idle speed and the PTO load relay will be disengaged.
3. SET -: Press and hold the accelerator to obtain the desired engine speed, then press and release the SET - switch. The current engine speed will be maintained. This action can be repeated as desired to a higher RPM value. The PTO set speed cannot exceed 2100 RPM. Tap Down: Press and release the SET - switch to reduce the engine speed by increments of 100 RPM. Coast: Press and hold the SET -switch to reduce the RPM by 200 RPM per second until the desired engine speed is reached or until the initial PTO standby speed is reached.
4. RES +: When a PTO set speed has been achieved, press and release the brake pedal. Engine speed will return to normal idle speed. The PTO LED will flash slowly indicating the previous PTO set speed has been retained in memory. Press and release the RES + to resume the previous PTO set speed. The PTO set speed cannot exceed 2100 RPM. Tap Up: Press and release the RES + to increase the engine speed by increments of 100 RPM. Accelerate: Press and hold the RES + to increase the RPM by 200 RPM per second until the desired engine speed is reached or until the maximum allowable PTO set speed is reached.

Remote Engine Start Control

The PTO system allows the engine to be remotely started while operating in the stationary PTO mode. The wiring system provides for connections to a remote engine start arming switch and remote starting switch. These connections are accessed through the upfitter connector.

The remote start function is initiated by a sequence of switch actions, in addition to several vehicle conditions. The following conditions must be met before attempting to remote start the engine. The vehicle ignition key can be in any position or removed from the ignition

1. The vehicle must be configured for stationary PTO operation.
2. The parking brake must be set.
3. The transmission must be in PARK (P).
4. The hood must be closed.

Once the above conditions are met, to continue with the remote start, use the remote PTO controls to do the following

1. Press and release the remote start arming switch.
2. Within five seconds of releasing the remote start arming switch, press and hold the remote engine start switch for about two seconds until the engine starts. Release the remote engine start switch.

To enable normal PTO operation following a remote start event, with PTO remote enable switch in the OFF position, press and release the arming switch. Then within five seconds, the PTO remote enable switch must be toggled to ON. The PTO system will then elevate engine RPM to standby speed and engage the PTO load. Press the remote PTO SET - or RES + switches to elevate PTO to the desired engine operating speed.

Remote Engine Shutdown Control

The PTO system allows for remote engine shutdown while operating the stationary PTO mode. This feature has the following functions

1. Engine shutdown using the operator remote switch: The vehicle wiring system provides remote engine shutdown switch connections, which can be accessed through the PTO upfitter connector.
2. Timed auto-engine shutdown: The timed auto-engine shutdown feature provides the means to shut down the engine automatically after a predefined time. PTO must be operational for this function to be active.
3. Engine shutdown based on critical engine conditions: The engine can be shutdown when PTO is operating if a critical engine condition is detected by the vehicle system (i.e., low oil, low oil pressure, hot engine, hot transmission, low fuel).

PTO - Preset Mode - Factory Default Settings

Reprogramming the PTOM for Fast Idle/PTO Using the Scan Tool

A scan tool must be used to enable certain PTO options and also to adjust the factory preset parameters to the desired settings. The scan tool menu driven device is a hand held scan tool that plugs into the datalink connector located underneath the dash near the driver seat.

For additional scan tool information, refer to Control Module References .

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Diagnostic Trouble Code (DTC) List - Vehicle
• Interior Lights Dimming Schematics
• Checking Aftermarket Accessories
• Instrument Panel Accessory Trim Plate Replacement (with RPO SLT)
• Fastener Caution
• DTC P061C
• Power Take-Off (PTO) Description and Operation