U0146: Communicatieverlies met de gateway A voor seriële data
Wat te doen
If a garage tells you their diagnostic equipment cannot connect to the car at all, that is not proof the car is dead — it is very often exactly what this fault looks like.
The gateway is the translator between the separate computer networks inside your car, and the diagnostic socket is wired to it rather than to the networks directly. So when the gateway goes quiet, the tool has nothing to talk to, and everything on the far side of it disappears from view at once.
Expect a long list of faults naming modules that are perfectly healthy. A dozen "lost communication" codes almost always mean one problem, not a dozen.
The car may also not start, because on many designs the conversation between your key, the body computer and the engine computer goes through the gateway. That gets investigated as a fuel or ignition problem and is neither — worth saying, because it saves a lot of wasted work.
And if the battery has been going flat over a few days, mention it. The gateway is one of the modules that decides when the car may switch itself off, and one that has stopped answering can leave the car awake all night. That is normally answered with a new battery and then a new alternator before anyone looks at the network.
Ask for the gateway's own fuse, feed and earth to be checked first. A module with no power looks exactly like a dead one, and a replacement gateway has to be programmed to the car — labour you cannot get back if it turns out to have been a fuse.
Wat deze code betekent
The gateway module has stopped being heard from. The general reasoning is at U0100, and U0447 explains what a gateway is — the translator between the vehicle's several separate networks, through which every message crossing from one to another passes.
A gateway that has gone silent is a different event from one reporting nonsense, and the difference is dramatic: everything on the far side of it disappears at once.
So the presenting picture is a scan tool listing lost communication with a dozen modules that have nothing wrong with them. U0100 already gives the rule — a dozen lost-communication codes describe one fault, not a dozen — and this is the purest example of it in the corpus. Every module on the other side of the gateway is alive, powered and talking to its own neighbours; nothing it says can reach the modules asking after it.
Which produces the situation that makes this hard to work on, and it is worth stating plainly because it is routinely misread. On practically every vehicle built this century the diagnostic socket is wired to the gateway rather than to the buses directly. So a tool that cannot connect to the vehicle at all is a completely expected consequence of this fault — and it is not evidence that the vehicle is dead. A workshop that reports "we cannot even talk to it" has, without realising, described the gateway.
Two further consequences.
The vehicle may not start, because on many designs the immobiliser conversation between the key, the body module and the engine module crosses the gateway. That gets investigated as fuel or ignition and is neither.
And the battery may go flat over a few days, because a gateway is normally among the modules deciding when the vehicle may sleep. A network that cannot agree to sleep does not — a fault answered almost every time with a new battery and then a new alternator.
Where to start, and it is cheap: the gateway's own supply. It has a fuse, an earth and usually a dedicated feed, and a module with no power is indistinguishable from a dead one. That check costs minutes and comes before any thought of a replacement, which on most vehicles has to be programmed and coded before it will pass a single message.
Waarschijnlijke oorzaken
Begin hier
- Zekering doorgebrand of voeding uitgevallen · eenvoudig
- Voeding of massa naar de module uitgevallen · gemiddeld
- Gecorrodeerde of losse stekker · eenvoudig
- Bedrading van de databus beschadigd · gemiddeld
Minder vaak
- Een andere module houdt de bus laag · specialistisch
- Gatewaymodule defect · specialistisch
Symptomen
Betrokken onderdelen
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