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Discussion Starter #1
The airbag warning light appeared on the dash of my 1999 166 Super over the weekend and has stayed on ever since.

Nothing was fiddled with, sorry scientifically adjusted, that might cause potential gremlins to appear, so was wondering is there anything specific I need to check, or reset that might cause it to go away?

MOT is due next month so really would like it go away as quickly as it appeared. Here's hoping for a loose connection or some easy fix. Any suggestions of places to start looking?

Thanks
Mark
 

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Functional description
The airbag system control unit M60 is supplied with power when the ignition switch is turned on (INT/A) at pin 5 by a line protected by fuse F2 in junction unit B1 .

Pin 14 is connected to the specific earth C50 .

When an impact of a set severity (determined by the control software) is detected, the control unit sends control signals to set off the modules:

to driver's Air Bag Q9 , via the steering wheel clockspring Q10 (from pins 1 and 2):
to passenger airbag Q11 (from pins 3 and 4);
to pretensioners - left-hand Q20 (from pins 10 and 11) and right-hand Q21 (from pins 6 and 7).
Pins 27 and 30 are connected to the sensor in the seat for disabling the passenger Air Bag K65 .

Pins 5 and 24 are connected to the passenger Air Bag disabling switch H75 .

When the system self-diagnostic function detects a fault or an impact is detected, control unit M60 sends a signal -from pin 13 - to the airbag anomaly warning light located in instrument panel E50 .

Pin 20 of M60 sends a signal to the passenger airbag disablement warning light located in instrument panel E50 .

These signals are earthed and turn on the warning lights since instrument E50 is ignition-activated (INT/A) - pin 15 of connector A - from a line protected by fuse F1 of junction unit B1 .

The red warning light is of the type known as 'smart' warning lights because an inner control circuit causes the warning light to light up even if the connection is broken or if the circuit connecting warning light and control unit is short-circuited to earth.

Self-diagnostic data may be read by connecting the unit to connector R10 : this receives signals from pin 9 of control unit M60 through the appropriate tester line.
 

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The yellow connectors under the seats are the first thing to look for broken wires or corroded terminals. You need to disconnect the battery first before checking.
 
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