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.

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

Component Connector End Views

Description and Operation

Power Take-Off (PTO) Description and Operation

Electrical Information Reference

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.