Impact Sensor: Service and Repair
Removing And Installing Airbag Sensor
Tools
Technical Values
Preliminary work
Preliminary work for front airbag sensor
1. Disconnect battery.
2. Remove front apron. Refer to Removing and installing front apron.
Preliminary work for centre airbag sensor
1. Disconnect battery.
2. Remove front seat.
3. Remove the rear side-panel lining. Refer to Removing and installing rear side-panel lining
4. Remove sill. Refer to Removing and installing inner sill.
5. Undo screw fastening seat belt to the body. Refer to Removing and installing front three-point belt.
General warning notes
Safety instructions for airbag sensor
CAUTION: Incorrect triggering of airbag modules.
- Danger of injury and material damage if airbag sensors are not handled correctly.
- Remove ignition key. Disconnect battery. Route or isolate ground strap so that all contact with a ground carrier (e.g. body, seat frame) is avoided.
- Always wait one minute after disconnecting the battery before disconnecting the connector from the sensor.
- The airbag sensor must not be removed with the plug plugged in.
- The airbag sensors cannot be interchanged. Install the sensor listed in the Spare Parts Catalogue (PET).
- Always replace fastening nuts and bolts of sensors after customer service and reworking.
- Never make alterations to the micro-encapsulated nuts and bolts which have a negative effect on the bond (e.g. using lubricant, loosening bolts and screwing them down again).
Tools and materials
Tools
Removal tool, universal NR.21
Removing airbag sensor
Removing sensor for front airbag
1. Unlock electrical connector -1- -A- and remove from sensor.
2. Unscrew the two fastening nuts -2- and remove the sensor.
Removing sensor for centre airbag
1. Disengage floor covering at the support and lay it in the vehicle interior.
2. Unlock locating peg -1- using the removal tool
3. Unscrew fastening screws -2- and nuts -3- and carefully pull the support up and out of the retaining points.
Incorrect triggering of airbag modules. Refer to Removing and installing airbag sensor.
4. Unscrew the two fastening nuts -2-.
5. Unlock electrical connector -A- and remove sensor.
Installing airbag sensor
Installing sensor for front airbag
INFORMATION: If a new component (e.g. sensor, airbag control unit, airbag unit) of the airbag system has to be installed, the new component will be supplied with a barcode sticker (tear-off label).
- Tear off the tear-off label -2- on the new component -1- and stick it under the heading Proof of airbag system check/component replacement in the Guarantee and Maintenance booklet.
- The replacement date and mileage must be documented and the booklet must be stamped with the dealer's stamp.
1. Position sensor on retaining bracket and screw it down with the fastening nuts -2-. M6: 8 Nm (6 ftlb.)±1 Nm (±0.5 ftlb.)
2. Push on the electric connector -1- and lock it.
Installing sensor for centre airbag
Incorrect triggering of airbag modules. Refer to Removing and installing airbag sensor.
INFORMATION:
- If a new component (e.g. sensor, airbag control unit, airbag unit) of the airbag system has to be installed, the new component will be supplied with a barcode sticker (tear-off label).
- Tear off the tear-off label -2- on the new component -1- and stick it under the heading Proof of airbag system check/component replacement in the Guarantee and Maintenance booklet.
- The replacement date and mileage must be documented and the booklet must be stamped with the dealer's stamp.
1. Position sensor on the body and screw it down with the fastening nuts -2-. M6: 8 Nm (6 ftlb.)±1 Nm (±0.5 ftlb.)
2. Push on the electric connector until it clicks into place.
3. Position the support and engage in lower side member.
4. Clip in locating peg -1- and check it is seated correctly.
5. Tighten the plastic fastening nuts -3-.
6. Screw in fastening screws -2-. Final tightening: 7.2 Nm (5.5 ftlb.)
7. Lay the carpet over the support and engage it.
Reworking
Work in wake of front airbag sensor
1. Install front apron. Refer to Removing and installing front apron.
2. Connect the battery.
3. Using the PIWIS Tester 97180, read out the fault memory and erase if required. If further faults exist, proceed in accordance with airbag diagnosis fault code.
Work in wake of centre airbag sensor
1. Screw in screw fastening seat belt to the body. Refer to Removing and installing front three-point belt.
2. Insert sill. Refer to Removing and installing inner sill.
3. Install the rear side-panel lining. Refer to Removing and installing rear side-panel lining
4. Installing front seat.
5. Connect the battery.
6. Using the PIWIS Tester 97180, read out the fault memory and erase if required. If further faults exist, proceed in accordance with airbag diagnosis fault code.