U0163: Lost Communication With Navigation Control Module
What to do
The satellite navigation has stopped working, and the thing worth knowing is that this can also change how the car drives — which almost nobody expects.
Modern cars use the map to look ahead. The gearbox holds a gear approaching a bend instead of changing at the wrong moment; cruise control eases off before a curve; the headlights begin turning into a corner; stop-start stays running where the car is about to move; a hybrid saves battery for a town it knows is coming.
So when the navigation goes quiet, the car can feel slightly different in ways that seem unrelated to it — a gearbox changing at odd moments, cruise control behaving differently, headlights that no longer swing into corners. Those get investigated as gearbox and radar faults, and a gearbox is an expensive thing to be wrong about. If this code is stored, say so before anything is taken apart.
The good news is that this is the mild version. The car simply goes back to reacting rather than anticipating, which is how every car worked until fairly recently. Nothing is at risk.
Check whether the radio still works. On many cars the navigation computer lives inside the stereo, so if that has gone too, the fault is there rather than here. Otherwise mention any recent work on the roof or headlining, since the aerial feeds this module.
What this code means
The navigation control module has stopped being heard from. The general reasoning is at U0100, and U0464 makes the argument that matters most here — that navigation data now feeds systems with nothing to do with directions.
It is worth restating in one line, because it is the reason this page has a higher severity than the screen beside it: the transmission holds a gear approaching a bend, adaptive cruise eases for a curve, adaptive headlamps begin turning before the steering does, stop-start stays running where the vehicle is about to move, and a hybrid saves charge for a city it knows is coming. All of that arrives from the map.
So a silent navigation module produces driveability complaints, and they get attributed to everything except the sat-nav. A gearbox changing at odd moments, cruise control behaving differently, headlamps that no longer swing into corners, stop-start that has become unpredictable. The transmission is the expensive thing to be wrong about, and a stored navigation code is the cheap explanation that should be eliminated first.
Silence has one advantage over bad data here, and it is worth knowing. The predictive functions degrade rather than misfire. A module sending wrong map data can make the gearbox pre-select for a bend that is not there; one sending nothing makes the vehicle simply revert to reacting rather than anticipating, which is how every vehicle worked until recently. So this version is milder, and "the car feels slightly less clever" is a fair description of it.
Where the fault usually is: the module's own supply and connector, and the roof aerial's feed — see U0185. On many vehicles the navigation computer is inside the head unit, so if the radio has gone too, U0184 is the better page.
Likely causes
Start here
- Blown fuse or failed supply · easy
- Corroded or loose connector · easy
- GPS antenna disconnected or damaged · moderate
- Damaged data bus wiring · moderate
Less common
- Module not coded to the vehicle · specialist
- Interrupted module programming · specialist
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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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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