U0170: Perda de comunicação com o sensor A do sistema de retenção
O que fazer
The airbag warning light means the airbags may not deploy correctly in a crash. The car drives normally, which is exactly why this gets postponed. It should not be.
This names one of the crash sensors placed around the outside of the car — in the front bumper structure, the pillars, the doors or at the back. They are there because the airbag computer sits in the middle of the car and would learn about a crash too late on its own.
One thing is worth asking the garage, because it decides how big a job this is. Is it one sensor that has gone quiet, or several? They sit on their own wiring loop from the airbag computer, so one silent sensor is a local problem — a plug or a broken wire — while several at once means the fault is at the computer end, and replacing sensors would be money spent on the wrong thing.
And if anything inside or on the car has been apart recently, say so. Seats out, carpets lifted, sill trims off, a bumper removed, accident repair however minor. Airbag connectors have a locking clip that has to click fully home; one pushed on but not latched reads as a fault while looking perfectly connected.
Do not have the light simply cleared, do not accept a second-hand airbag module, and refuse any offer to fit a resistor in place of a sensor.
O que este código significa
A restraints system sensor has stopped being heard from. The general reasoning is at U0100, U0471 explains what these sensors are and why they sit at the extremities of the vehicle, and U0151 carries the restraints safety rules — nothing touched with the battery connected, and a resistor never substituted for a component.
This page establishes the family from U0170 to U0179, and the one thing it adds to U0471 is a diagnostic split that only silence makes available.
These sensors are usually not on the vehicle's main data bus. They sit on a dedicated loop from the restraints module — its own pair of wires, its own connectors, deliberately separate so that a fault anywhere else on the vehicle cannot take the crash sensing with it.
Which means the pattern of what has gone quiet tells you where to look, before any instrument comes out.
- One sensor silent, the others reporting. The fault is on that sensor's own branch: its connector, its wiring, or the sensor. A small, local, findable problem.
- Several or all silent at once. The fault is upstream of all of them — the restraints module itself, its supply, or the trunk of the loop where it leaves the module. Replacing sensors here is money spent on the wrong end, and the U0151 page is the better one.
And silence has a characteristic cause that bad data does not: an open circuit. A sensor reading implausibly is usually disturbed or mis-mounted; one that has gone quiet is usually simply not connected — which is why U0152's shorting bar matters here too. A connector pushed on but not latched can leave the circuit shorted rather than made, and it looks perfectly seated.
So after any interior or body work, unlatch and properly re-seat the connectors rather than inspecting them. Inspection cannot tell the two states apart.
Causas prováveis
Comece aqui
- Conector corroído ou frouxo · fácil
- Sensor de impacto deslocado durante reparo de funilaria · moderado
- Chicote elétrico danificado · moderado
- Infiltração de água no conector · moderado
Menos comum
- Dano físico por detritos da via · moderado
- Módulo do sistema de retenção com defeito · especializado
Sintomas
Componentes envolvidos
Informação, não instrução
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