Failure phenomenon: a 2004 Audi A6 1.8T annual car rollover accidents due to plant maintenance. Accident driver-side seat air bag explodes, the belt locking. After replacing the air bag control unit, and a new driver’s seat belt, airbag found dashboard warning light.
Failure Analysis: car accident caused only driver’s side seat airbags detonate, and has been replaced, but also replace the air bag control unit, why the police do?
First, connection failure diagnostic VAS5052 author self-diagnosis, the airbag system 15 to select, read fault codes, found within the control unit stores a fault code: 01219mdash; mdash; driver side rear side airbag igniter N201 short to ground.
When sheet metal because the car is detachably repaired harness room, so I suspect the rear seat airbag harness the connection is not secure, then turn off the ignition switch, the rear seat is removed check its plug , upon inspection of the plug without loosening. However, after the ignition switch is turned found airbag warning lamp remains, then simply turn off the ignition switch, unplug the plug seat left airbag harness, continues to read the fault code, the fault code is displayed as 01219mdash; mdash; driver’s side rear side airbag igniter squib resistance is too large N201. It seems airbag or its wiring harness connector problem.
To further confirm the point of failure, the author of the two rear seat airbag connected to a swap bit harness connector, continue to read the fault code, the fault code is displayed 01220mdash; mdash; passenger-side rear side safety N202 airbag igniter shorting to ground, thereby eliminating failure balloon connector harness, the left rear seat airbag seems indeed a problem. After removing the rear seat back an airbag which has been found to burst open a little, but not all burst open, the bag did not burst (reference), resulting in not found in the previous repair process.
FIG.
troubleshooting: After replacing seat airbag and an airbag control unit, test, the airbag warning lamp goes out, failure to completely eliminate.
Fault Summary: For the airbag alarm, weLike to use the self-diagnostic check failure range, if you encounter an airbag squib resistance is too large, generally considered to be open circuit, check its connection plug. If the short to ground airbag igniter, can focus on checking the airbag, the airbag resistance is generally 2 ~ 3 Omega ;, can find a resistor with resistance, the airbag igniter replacement, then clear the fault code operation. If you can clear out the fault code, it indicates a problem with the airbag must be replaced. In particular the power seat airbag cable plug, since the seat is detachably put little attention harness fixing clip broke under the seat, the seat and the back and forth movement of the plug will enable the force, resulting in loose or fall off the plug, there electric seat airbag alarm function failure or other malfunction.
(Liujian Bo)