What was the type and status displayed on the tester? (I.e. faulty signal/signal too low, etc permanent or intermittent fault)Bag is located within the right bolster of driver's seat back.
Check connection underneath the seat.
According to Vadis for faulty signal:-
"If the resistance in the circuit is too high for 3-5.5 seconds, diagnostic trouble code SRS-422 is set.
Substitute value
-Nothing.
Possible source
-Open circuit.
-Faulty side air bag.
-Contact resistance or oxidation.
Fault symptom[s]
-SRS warning lamp comes on."
They have a special shorting link to bypass the air bag. If fault now changes to intermittent and back to permanent when you reconnect the airbag then suspect the airbag is faulty.
Note that you will not be able to erase DTC until status has changed to intermittent (i.e. fault fixed) I plugged into a C70 the other day and had a SRS-412 for Left SIPS but it was intermittent so it cleared and didn't come back.
HTH
Sean