On request here is a listing for OBD1 GM vehicles.

GM OBD-1 Diagnostic Trouble Codes
For 1995-previous model year EFI-equipped GM vehicles. NOTE: Some codes not supported on all models, consult your specific vehicle's service manual for the correct trouble code list and description for your application.
DTC - 12 No distributor reference pulse (diagnostic test active)
DTC - 13 Oxygen sensor circuit open or no activity
DTC - 13 Left bank O2 sensor circuit open or no activity
DTC - 14 Engine coolant temp sensor error (high temp indicated)
DTC - 15 Engine coolant temp sensor error (low temp indicated)
DTC - 16 System voltage too low
DTC - 17 Camshaft position sensor error
DTC - 21 Throttle Position sensor error (signal high)
DTC - 22 Throttle position sensor error (signal low)
DTC - 23 Intake air temp sensor error (low temp indicated)
DTC - 24 Vehicle speed sensor error (open circuit or no activity)
DTC - 25 Intake air temp sensor error (high temp indicated)
DTC - 26 Quad Driver Module (QDM A) error
DTC - 28 Auto transmission range pressure switch error
DTC - 31 Wastegate solenoid circuit error
DTC - 31 Gear Position Switch (PRNDL) error
DTC - 32 EGR system failure
DTC - 33 MAP sensor circuit error (signal high indicating low vacuum)
DTC - 34 MAP sensor circuit error (signal low indicating high vacuum)
DTC - 35 IAC problem or idle error
DTC - 36 MAF sensor error
DTC - 36 24x Crankshaft position sensor circuit error
DTC - 36 4T60-E Shifting Error
DTC - 37 TCC brake switch circuit error
DTC - 38 TCC brake switch circuit error
DTC - 39 Clutch switch circuit error
DTC - 39 TCC error
DTC - 41 Ignition control error
DTC - 41 MEM-CAL error
DTC - 41 CI Cam Sensor Signal error
DTC - 42 Ignition bypass circuit error
DTC - 43 Knock sensor error
DTC - 44 Oxygen sensor error (lean condition indicated)
DTC - 44 Left bank O2 sensor error (lean condition indicated)
DTC - 45 Oxygen sensor error (rich condition indicated)
DTC - 45 Left bank O2 sensor error (rich condition indicated)
DTC - 46 Pass-Key II (VATS) system error - circuit out of freq range
DTC - 47 UART (serial data) circuit error
DTC - 51 PROM error
DTC - 51 Incorrect MEM-CAL
DTC - 52 Fuel cal-pak incorrect or missing
DTC - 53 System voltage too high
DTC - 53 Digital EGR Valve solenoid 1 error
DTC - 54 Fuel pump circuit low voltage
DTC - 54 Digital EGR Valve solenoid 2 error
DTC - 55 ECM error
DTC - 55 Digital EGR Valve solenoid 3 error
DTC - 56 Quad Driver Module (QDM B) error
DTC - 57 Boost Control error
DTC - 58 Trans fluid temp sensor circuit error (low voltage)
DTC - 58 VATS system error
DTC - 59 Trans fluid temp sensor circuit error (high voltage)
DTC - 61 A/C system performance
DTC - 63 Right bank O2 sensor circuit error
DTC - 63 MAP sensor circuit signal voltage high (low vacuum indicated)
DTC - 64 Right bank O2 sensor lean exhaust indicated
DTC - 64 MAP sensor circuit signal voltage low (high vacuum indicated)
DTC - 65 Right bank O2 sensor rich exhaust indicated
DTC - 66 A/C pressure sensor circuit error (low pressure indicated)
DTC - 67 A/C pressure sensor circuit error
DTC - 68 A/C clutch relay circuit error (shorted to ground)
DTC - 69 A/C clutch relay circuit error (open circuit indicated)
DTC - 69 A/C high pressure switch error
DTC - 70 A/C pressure sensor circuit error (high pressure indicated)
DTC - 71 A/C evaporator temp sensor circuit error (low temp indicated)
DTC - 72 VSS signal circuit error
DTC - 73 A/C evaporator temp sensor circuit error (high temp indicated)
DTC - 75 Digital EGR solenoid #1 circuit error
DTC - 76 Digital EGR solenoid #2 circuit error
DTC - 77 Digital EGR solenoid #3 circuit error
DTC - 79 Transmission fluid overtemp
DTC - 80 Transmission component slipping
DTC - 82 3x Crankshaft position sensor circuit error
DTC - 85 PROM error
DTC - 86 A/D error
DTC - 87 EEPROM error (flash memory error)
DTC - 90 TCC error
DTC - 93 Transmission pressure control solenoid circuit error
DTC - 96 Transmission system voltage low
DTC - 98 Invalid PCM program
DTC - 99 Invalid PCM program

Here is the website for needed reference.
http://www.gmtuners.com/OBD1_DTC.htm