Air Bag - Upddated Removal and Installation
TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERSDATE: October 1986 REF. NO. MBNA 91/7
SUBJECT: REMOVAL AND INSTALLATION OF AIR BAG UNIT ALL MODELS WITH AIR BAG
This Service Information supersedes the removal and installation procedure outlined in Job no. 91-660 on Service Microfiche "Air Bag and Seat Belt Tensioner".
Figure 1 - Models 124, 126 & 201 Under Front Passenger Footrest:
Figure - 2 Model 107 At Parking Brake:
Procedure
Removal
1. Turn ignition key to position "0", disconnect and cover negative battery terminal.
2. Disconnect the 10-pole connector (arrow, Figures 1 and 2).
Figure 3 - Loosen Air Bag Unit:
3. Loosen air bag unit (51) by loosening both torx capscrews (66) using special tool no. 126 589 00 10 00 (Figure 3) .
Figure 4 - Disconnect Connector and Remove Air Bag Unit:
Disconnect connector (55, Figure 4) and remove air bag unit.
NOTE: A short circuiting bridge will automatically become effective in the unit upon removal of the connector.
NOTE: No further work should be performed on the air bag unit. If removed for a long period of time, the unit must be locked in a safe place.
Only complete air bag units are available as replacement parts.
Figure 5 - Store Air Bag Unit with Padded Side Up, Electrical Connector Down:
CAUTION! Store the air bag unit with the padded side facing up and the electrical connector down (Figure 5).
Do not stack air bag units on top of one another.
Special Handling Requirements of Air Bag Unit
Do not allow the contact pins to came in contact with any grease or cleaning solution.
Do not subject air bag unit to temperatures above 100~C ( 212~F).
Extreme caution must be used when handling the air bag unit. If the unit accidently falls from a height greater than 20 inches (50 cm), the air bag unit will be inoperative and may no longer be installed.
Installation
CAUTION! Before installing the air bag unit, make certain that the negative battery terminal is disconnected and covered, the 10-pole connector is disconnected, and the ignition key is in position "0".
Figure 6:
1. Attach connector (55, Figure 6) to air bag unit (connector must audibly connect)
Figure 7:
2. Place air bag unit (51) on steering wheel (9) and tighten both torx capscrews (66) using special tool no. 126 589 00 10 00 (Figure 7).
Tightening torque: 6 N-m
3. By lightly hitting the steering wheel rim with your hand, check to see if a rattling noise exists. The rattling noise may be caused by excessive play of the air bag unit on the steering wheel.
Figure 8:
3a. Remedy against rattling noise:
Steering Wheel version 2, installed up to 11/85 production (Figure 8).
NOTE: Steering wheel version 1 was not available on U.S. specified vehicles.
Figure 9:
On the right contact bridge (57) an adjuster (80) can be used to reduce/eliminate axial play (Figure 9).
For example, if there is excessive play bottom left and/or top right, turn the adjuster (80) to the left using a small screwdriver until the play has been eliminated.
57 Right contact bridge 66 Button head screw 80 Adjuster
Figure 10:
CAUTION! The air bag unit does not have to be removed. A channel is fused into the foam padding in the area of the adjuster to guide the adjustment tool (arrow, Figure 10).
Figure 11:
3b. Remedy against rattling noise:
Steering wheel version 3
NOTE: The new steering wheel version can be visually identified by the chamfer on the left and right side of the air bag unit (arrows, Figure 11).
Loosen both torx capscrews and align the air bag unit so that it sits evenly on the steering wheel. First tighten the left torx capscrew to 6 N-m. Slightly pull the right side of the unit away from the steering wheel and then tighten the right torx capscrew to 6 N-m.
4. Test the SRS using tester 126 589 10 21 00. Observe all safety precautions.
5. Upon completion of test, ensure that the 10-pole connector is connected and securely in place, and that the negative battery terminal has been connected and tightened. Replace carpeting.
Figure 12:
6. Ensure that the SRS control light (arrow, Figure 12) , horn and combination switch function properly.
NOTE: Warranty claims for air bags replaced due to rattling noise will not be accepted.
All air bags and ETR's returned for warranty consideration must be shipped in original container, observing all applicable safety regulations concerning the shipment of pyrotechnic components.
Do not deploy the air bag or ETR prior to shipping. Warranty claims received for those that are deployed will be denied.
Special Tool Information
Part Name Part Number
SRS Tester 126 589 10 21 00
90~ Torx wrench T30 126 589 00 10 00
(70 mm x 24 mm)
Time Allowance
According to the latest time guide microfiche