Code U0117 indicates that the main engine computer (PCM) has lost its communication link with the Power Take-Off (PTO) control module. This typically means the PTO module is not responding to network messages, which can prevent the vehicle's auxiliary equipment from operating.
An open, short, or high-resistance connection in the CAN bus wiring or the power/ground circuits to the PTO module is the most common cause.
A blown fuse, faulty relay, or low system voltage preventing the PTO module from powering up and communicating.
The PTO module itself has suffered an internal hardware failure, causing it to drop off the vehicle's communication network.
A fault in the engagement switch or related sensor causing the PTO module to lock up or fail to initialize properly.
Extremely rare; the main engine computer is almost never the reason a secondary module stops communicating.
No. It is a common misconception that a 'lost communication' code means the PCM has failed. It almost always means the secondary module (the PTO module) or the wiring between them has an issue. Replacing the PCM will rarely fix this code.
Usually yes, the vehicle can be driven normally. However, any auxiliary equipment powered by the PTO system will not function until the issue is resolved.
PTO stands for Power Take-Off. It is a system that transfers engine power to auxiliary equipment, commonly found on commercial trucks for operating dump beds, winches, or hydraulic lifts.
Yes, low system voltage can cause modules to drop off the communication network, triggering communication codes like U0117. Always ensure the battery and charging system are healthy before replacing parts.