Found this and it worked for me on my 2002 Terrano 3.0 SVE.
1. Turn ignition switch “ON”.
2. After “AIR BAG” warning lamp lights for 7 seconds, [i.e. when it stops running solid and starts flashing] turn ignition switch “OFF” within 1 second. [DO NOT SWITCH IT TO LOCK, SWITCH IT TO ACC]
3. Wait more than 3 seconds.
4. Repeat steps 1 to 3 two times. (Perform 3 times in total.)
5. Turn ignition switch “ON”.
SRS is now in Diagnosis mode.
In diagnosis mode, you're going to hope the light flashes slowly. 2 seconds off, 3 seconds on, and repeats. If your light does this, this means that the computer detected a previous error that hasn't been erased. This is good.
If you get ANY OTHER result, go to Nissan. You've got a real problem that needs a real fix.
6. If “AIR BAG” warning lamp operates as above, just turn ignition switch “OFF” to reset from Diagnosis mode to User mode and to erase the memory of the malfunction.
7. Turn ignition switch “ON”. “AIR BAG” warning lamp operates in
User mode. (it should stay on for 7 seconds, then go off, like normal.):clap