U0117: Lost Communication With PTO Control Module
What to do
The equipment — tipper, crane, mixer, pump, winch — will most likely not run at all, and the vehicle will drive normally.
That is the safe outcome: when the computer controlling the power take-off goes quiet, the rest of the vehicle assumes it is not engaged and refuses to run the equipment.
One thing to check before driving off, though. If the PTO was engaged when the fault appeared, confirm the equipment is actually disengaged rather than trusting the dashboard, because the dashboard has lost the thing that was telling it.
Contact whoever built or converted the body before a general workshop. This wiring is almost always fitted by the converter rather than the vehicle manufacturer, and the fault is nearly always at the join between their wiring and the chassis wiring — a corroded splice, an earth on painted metal, a cable rubbing on something that moves.
If it works from cold and fails once warm, or fails on rough ground, say so. Both descriptions point straight at that join and save a great deal of searching.
What this code means
The power take-off control module has stopped being heard from. The general reasoning is at U0100, and U0465 explains what a PTO is and why its published state governs a set of safety interlocks.
Silence and bad data fail differently here, and the difference is worth stating because one of them is much better than the other.
A module reporting an implausible state leaves the interlocks acting on something untrue. A module that has gone silent normally makes every other system default to not engaged — which is the safe assumption, and usually means the equipment simply will not run.
So the common outcome is a vehicle that drives perfectly and a tipper, crane or pump that does nothing, which is inconvenient rather than dangerous. The uncommon outcome is the one to check for: if the PTO was engaged when communication was lost, the mechanism may still be engaged while the vehicle believes it is not. Confirm the equipment is actually disengaged before driving, rather than trusting a dashboard that has lost its source.
Where the fault is has the same answer as U0465, and it is worth acting on rather than reading past. PTO wiring is installed by the body builder rather than the vehicle manufacturer, so the fault is almost always at the join between the chassis harness and the body harness — a spliced connection that has corroded, an earth taken to painted metal, a cable routed against something that moves. A vehicle that works from cold and fails once warm, or fails on rough ground, is describing that join.
Contacting the converter before a franchised workshop is usually the shorter route, because they installed it and hold the drawings.
Likely causes
Start here
- Poor wiring splice in an aftermarket installation · moderate
- Corroded or loose connector · easy
- Corroded earth connection · moderate
- Damaged wiring harness · moderate
Less common
- Blown fuse or failed supply · easy
- Damaged data bus wiring · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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