My book says that it means "closed throttle position switch" Ed
Diagnostic Trouble Codes.
The average Nissan automobile has more than 400 diagnostic troubleshooting codes. You can obtain a complete list of diagnostic codes from most Nissan dealerships.
DTC stands for Diagnostic Trouble Code.
Trouble code P0171 means: Fuel Trim System Lean (Bank 1) Trouble code P0174 means: Fuel Trim System Lean (Bank 2)
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.
to find out who messed it up0-
Trouble code P0441 means: Evaporative Emission System Incorrect Purge Flow Trouble code P0446 means: Evaporative Emission System Vent Control Circuit
Code 12 just means that the ECM is going into diagnostic mode, this is NOT a trouble code! Code 12 should blink a couple of times pause then blink your trouble codes if you have any. If you have no trouble codes, it will resume to blink code 12 again.
Trouble code P0171 means: Fuel Trim System Lean (Bank 1) Trouble code P0300 means: Multiple Cylinder Misfire Detected
You must use a Diagnostic code scanner that can erase trouble codes.
Diagnostic equipment is needed to read codes on a 92 Golf. DLC is located in dashboard beneath heater controls.
The light is on because there is a problem with the system. Until the problem is fixed the light will stay on. Your local auto parts store can read the DTC's ( diagnostic trouble codes). The codes will direct you to the problem.