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Audi-Resource - Airbag

 

 

 


In this document

J234- Airbag control unit pin assignment

J234- Removing and installing airbag control unit

J655- Battery cut-off

 

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01- Engine Control Unit

02 - Transmission Control Unit

03 - Brake electronics

05 - Access / Start Auth

07 - MMI Head Unit

08 - Climatronic

09 - Central Electric 1

13 - Adaptive CC

15 - Airbag

16 - Steering Wheel

17 - Instrument Cluster

18 - Aux Heating

19 - Gateway

28 - Rear Climatronic

34 - Level Control

36 - Driver Seat memory

38 - Roof Electrics

3C - Lane Change

42 - Door Electronic Drivers

46 - Central Convenience

47 - Sound System

4F - Central Electronics 11

52 - Door Electric Passenger

53 - Parking Brake

55 - Headlight Control

61 - Energy Manager

62 - Door Elec RL

65 - Tyre Pressure

66 - Rear Seat

67 - Voice Control

77 - Telephone

 

 

 

15 - Airbag

Coding

 

a

J234- Airbag control unit pin assignment

 

The rectangular tabs

(e.g. 27, 28) are the normally-closed contacts for the ignition circuits underneath

(e.g. 55, 56).

 

Read measured value block

The following measured values are displayed:

Output signals:

 

Measured value block 001:  

Airbag driver side                  (correct; too small; too large; endp. earth; endp. positive)

Airbag passenger side           (correct; too small; too large; endp. earth; endp. positive)

Belt tensioner driver side       (correct; too small; too large; endp. earth; endp. positive)

Belt tensioner passenger side               (correct; too small; too large; endp. earth; endp. positive)

 

Measured value block 002:

Rear belt tensioner driver side                              (correct; too small; too large; endp. earth; endp. positive)

Rear belt tensioner passenger side       (correct; too small; too large; endp. earth; endp. positive)

Rear centre belt tensioner                     (correct; too small; too large; endp. earth; endp. positive)

Vacant

 

Measured value block 003:

Supply voltage                          (correct; too small)

Vacant

Belt tensioner driver side                      (too small; too large; endp. earth; endp. positive; n.defined; belt YES; belt NO)

Belt tensioner passenger side       (too small; too large; endp. earth; endp. positive; n.defined; belt YES; belt NO)

 

 

Measured value block 004:

Belt detector rear driver side

(too small; too large; endp. earth; endp. positive; n.defined; belt YES; belt NO)

 

Belt detector rear passenger side

(too small; too large; endp. earth; endp. positive; n.defined; belt YES; belt NO)

 

Rear centre belt detector

(too small; too large; endp. earth; endp. positive; n.defined; belt YES; belt NO)

 

 

Measured value block 006:

Front side airbag igniter driver side       (correct; too small; too large; endp. earth; endp. positive)

Front side airbag igniter passenger side               (correct; too small; too large; endp. earth; endp. positive)

Rear side airbag igniter driver side        (correct; too small; too large; endp. earth; endp. positive)

Rear side airbag igniter passenger side (correct; too small; too large; endp. earth; endp. positive)

 

 

Measured value block 008:

Airbag driver side 2-stage                     (correct; too small; too large; endp. earth; endp. positive)

Airbag passenger side 2-stage             (correct; too small; too large; endp. earth; endp. positive)

Driver side curtain airbag igniter            (correct; too small; too large; endp. earth; endp. positive)

Passenger side curtain airbag igniter     (correct; too small; too large; endp. earth; endp. positive)

 

 

Measured value block 008:

Front passenger airbag key switch (result from hardware and software test)

(On; Off)

Front passenger airbag key switch (hardware test)

(too small; too large; endp. earth; endp. Positive; n.defined; On fp airbag; Off fp airbag)

Front passenger airbag key switch (software test)

(too small; too large; endp. earth; endp. Positive; n.defined; On fp airbag; Off fp airbag)

 

 

Measured value block 011:

Knee airbag igniter, driver side              (correct; too small; too large; endp. earth; endp. positive)

Knee airbag igniter, passenger side      (correct; too small; too large; endp. earth; endp. positive)

 

 

 

 

 

 

 

J234- Removing and installing airbag control unit

a

 

- Remove the centre console at the rear.

A General Body Repairs, Interior.

- Remove the insulation.

 

- Open the lock -3-.

 

- Unplug the connector -4-.

 

- Unscrew the nuts -2- (3x). (tightening torque 9 Nm).

 

- Remove the control unit -1-.

 

J655- Battery cut-off

a

When the airbag control unit has triggered a battery cut-off by way of the crash signal or the final control element test, the battery can be switched back on by pressing the yellow button -1-.

1- Restart button

2- Retainer tab

3- Connector to airbag control unit

4- Cover

The battery cut-off relay

a

 

(J655) will be replaced from around MY 2005 by

the battery isolation igniter

(N253)

 

Fitting location of relay/igniter:

  In boot at right in front of battery

 

J655 - Battery cut-off relay

              

1 - Yellow button (reset function)

     Not present in all vehicle

     versions !!!

     If present, the

     button must be pressed after crash

     signal triggering or

     airbag final control diagnosis fully

2- Retainer tab

3 - Connector

     To airbag control unit (J234)

     and terminal 15

4- Cover

 

From software release S082 and S084 and with button omitted,

after a crash the relay for battery cut-off (J655) must be replaced.

 

 

 

 

 

 

 

 

 

 

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