I am not certain with a'92, but on my '89 Silverado (which also has the OBD 1 system) you insert a bent paperclip into two female pins in a plug directly under the dash. The code will be displayed as a flashing light (the brake light on the dash in my case). The number of long and short flashes detrmine the code. For example, my brake light gave 8 short flashes followed by one long flash indicating "81". If you go to an Auto Zone or an Advanced Auto Parts they should be able to do this for you there as well.
1994 year and up need a code reader to retrieve their codes. Most auto parts stores offer this as a free service.
Some Haynes manuals have ECU codes
If it is OBD 1, yes.
You need an OBDII scanner to retrieve the trouble codes.
Trouble code PO151
The OBDII system is used in 1995 and later model vehicles. An OBDII scanner must be used to retrieve the trouble codes.
You will need a diagnostic scanner to retrieve the codes.
With an OBD2 scan tool connected to the OBD connector.
You need an OBDII scanner tool to retrieve the trouble codes. AutoZone and similar auto parts stores offer free scans.
You will need an OBD II tester to retrieve the trouble codes. The connector is located under the dash (in plain view) within 12 inches on either side of the steering column as this is mandated by the Federal Government.
1995 and later Mazda B-Series Pick-ups incorporate the OBDII diagnostic system and you will need a scanner to retrieve the trouble codes. Some auto parts stores will scan free if the check engine light is on.
Chiltons owner manual has complete eccm trouble codes