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U017B Lost Communication With Restraints System Sensor L

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U017B means sensor L of the restraint system, the twelfth remote crash sensor in J2012 order, no longer answers. No manufacturer documents U017B publicly, so which component sits behind the letter depends on the car. One example of how sensor counts grow: airbag control units can also run pedestrian protection, fed by acceleration sensors or by a pressure tube in the front bumper. In the Bosch pressure tube system, an air-filled silicone tube in the bumper has a pressure sensor at each end, and the unit can raise an active bonnet or fire a windscreen airbag 10 to 15 ms after striking a pedestrian. Bumper replacement or a parking knock are then typical reasons for a lost sensor. The airbag or pedestrian protection warning lights; no MIL.

Likely causes

Sensor or its connector not refitted after bumper replacement
Sensor or wiring damaged by a minor front or side knock
Corroded connector in an exposed mounting position
Sensor L internally failed

Symptoms

  • Airbag or pedestrian protection warning on
  • Protective function assigned to sensor L disabled
  • Fault appears after body or bumper work

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–700
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

restraints sensor lcrash signal wiring

Related codes

U0151U017AU017CU047C

References: bosch-mobility.com, bosch-mobility.com.