Airbag D M Fault Code 23 - Aston Martin DB7 Workshop Manual

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Airbag D M Fault Code 23
Safing sensor input- battery feed/return open circuit.
Normal Operation
The diagnostic module measures the voltage on
diagnostic module pin 1 -9 at all times. The voltage
can be as high as 25 volts when the backup power
supply is fully charged.
Pin 1 -9 is connected to pin 2-11 inside the safing
sensor and the voltage on both these pins shou Id be
the same. If the voltage on pin 2-11 fails below the
voltage on pin 1 -9, a code 23 is generated.
Possible Causes
• Open circuit in the wiring to diagnostic module
pin 1-9.
• Open circuit in the wiring to diagnostic module
p i n 2 - n .
Fault Analysis
WARNING: Read and adhere to all warnings and
safety procedures at the start of this section when
working on the airbag system.
1. Disarm the airbag system and fit airbag simulators
(6.4.21.4).
2. Disconnect the diagnostic connector and thesafing
sensor connector. Check for continuity from DM
pi n 1 -9 to safing sensor harness connector pi n 7 and
from D M p i n 1-11 to safing sensor harness connector
pin 6.
If the continuity of both leads is good, go to step 3.
If a continuity fault is detected, repair the wiring as
necessary. Reconnect ail components. Clear the
code 23. Rearm the airbags (6.4.21.4).
3. Check the continuity between pins 6 and 7 of the
safing sensor.
If the continuity is good, replace the diagnostic
module. Rearm the airbags (6.4.21.4).
If a continuity fault is detected, replace the safing
sensor. Reset the code 23. Rearm the airbags
(6.4.21.4).
September 1996 6-89