| Code | Fehler Bezeichnung |
| 12 | Diagnostic Mode |
| 13 | Oxygen sensor or circuit |
| 14 | Coolant sensor or circuit / high temperature indicated |
| 15 | Coolant sensor or circuit / low temperature indicated |
| 16 | System voltage high / ECM voltage over 17.1 volts (could be alternator) (3.8L) |
| 16 | DIS (Distributorless Ignition System) circuit (Chevrolet only) |
| 16 | Low resolution pulse (5.7L P-code engines) |
| 16 | Transmission speed error (4L60 or 4.3L "S" & "T" series w/ manual) |
| 16 | System voltage high or low (3.8L) |
| 17 | Crank signal circuit shorted or faulty ECM |
| 17 | Camshaft position sensor circuit (3.4L) |
| 18 | Crank signal circuit open or faulty ECM |
| 18 | Injector circuits (engine VIN code P - 5.7L) |
| 18 | Cam and crank sensor sync error (DIS engines) (3.8L) |
| 19 | Fuel pump circuit short |
| 19 | Crankshaft position sensor (1988-1991 models) |
| 20 | Fuel pump circuit open |
| 21 | Throttle Position Sensor (TPS) circuit or plunger |
| 22 | Throttle Position Sensor (TPS) out of adjustment |
| 21/22 | Grounded wide-open-throttle (WOT) circuit at same time |
| 23 | Manifold Absolute Temperature (MAT) sensor or circuit / low temp. |
| 23 | Intake Air Temperature (IAT) sensor circuit (1995 models) |
| 23 | Electronic Spark Timing (EST) - bypass circuit problem (Cadillac DFI models) |
| 24 | Vehicle Speed Sensor (VSS) or circuit |
| 25 | Manifold Air Temperature (MAT) sensor or circuit / high temp. |
| 25 | Modulated displacement failure (1981 Cadillac V8-6-4 only) |
| 25 | Electronic Spark timing (EST) (Cadillac HT4100 only) |
| 26 | Quad Driver Circuit (dealer serviced) |
| 26 | Evaporator emission (EVAP) purge solenoid circuit (VIN P - 5.7L) |
| 26 | Throttle switch circuit shorted |
| 27 | Throttle switch circuit open |
| 27 | Gear Switch Diagnosis (dealer serviced) |
| 27 | EGR vaccum control signal valve circuit (VIN P - 5.7L) |
| 27 or 28 | Quad-driver error (5.7L P-code engines) |
| 28 | Pressure Switch Manifold check (PSM) vehicles w/ 4L80-E transmission |
| 28 | Same as Code 27 |
| 29 | Same as Code 27 |
| 30 | ISC circuit problem (Cadillac TBI) |
| 30 | RPM error (Cadillac MFI) |
| 31 | Turbo over boost (Turbo models) |
| 31 | Park/Neutral switch (3.3L) |
| 31 | Manifold Air Temperature (MAT) sensor or circuit (Cadillac DFI models) |
| 31 | Canister purge solenoid circuit |
| 31 | Camshaft sensor or circuit |
| 31 | EGR circuit (1988 to 1990 TBI) |
| 31 | Shorted MAP sensor circuit |
| 32 | BARO sensor or circuit (carbureted models) |
| 32 | EGR circuit (fuel-injected models) |
| 32 | Digital EGR circuit (3.1L) |
| 32 | Open MAP sensor circuit |
| 33 | Manifold Absolute Pressure (MAP) sensor or circuit (low vacuum) |
| 33 | MAF (Mas Air Flow) sensor or circuit |
| 33 | Manifold Absolute Pressure (MAP) sensor signal voltage high |
| 34 | Manifold Absolute Pressure (MAP) sensor signal voltage low |
| 34 | MAF (Mas Air Flow) sensor or circuit |
| 34 | Vacuum sensor or MAP sensor (high vacuum) or circuit (3.8L) |
| 35 | Idle Air Control (IAC) valve or circuit |
| 35 | Idle Speed Control (ISC) switch or circuit (shorted) |
| 35 | BARO sensor or circuit (shorted) (Cadillac DFI models) |
| 36 | BARO sensor or circuit (open) (Cadillac DFI models) |
| 36 | Mass Air Flow (MAF) sensor burn-off circuit |
| 36 | Distributorless Ignintion System (DIS) (Quad-4) |
| 36 | Transaxle shift control (3.8L) |
| 36 | Closed throttle shift control (1991) |
| 36 | 24X signal circuit error (3.4L - 1995) |
| 36 | DIS ignition circuit (Corvette only) |
| 37 | MAT sensor or circuit (shorted) (Cadillac HT4100) |
| 37 | MAT sensor temp. high (1984-1986) |
| 37 | Brake switch stuck on (4L60-E transmission) |
| 38 | MAT sensor or circuit (open) (Cadillac HT4100) |
| 38 | Brake Input Circuit (brake light switch) |
| 38 | MAT sensor temp. low (1984-1986) |
| 38 | Brake switch stuck off (4L60-E transmission) |
| 39 | Torque converter clutch |
| 39 | Knock sensor circuit shorted (4.3L, manual trans., "S" & "T" pick-up) |
| 40 | Power steering pressure switch circuit |
| 41 | No distributor signals to ECM, or faulty ignition module |
| 41 | Cam sensor or circuit (3.8L) |
| 41 | Cylinder select error |
| 41 | Quad 4 engine 1XReference (check ignition module / ECM wiring) |
| 41 | Electronic Spark Timing (EST) circuit (Cadillac) |
| 41 | Opti-spark EST circuit open or grounded (5.7L "F" and "Y" bodies) |
| 42 | Opti-spark EST circuit grounded (5.7L "F" and "Y" bodies) |
| 42 | Electronic Spark Timing (EST) circuit |
| 42 | Front oxygen sensor lean (Cadillac MFI) |
| 43 | Electronic Spark Control unit (ESC) |
| 43 | Throttle Position Sensor (TPS) out of adjustment |
| 43 | Front oxygen sensor rich (Cadillac MFI) |
| 43 | Knock sensor signal |
| 44 | Oxygen sensor or circuit - lean exhaust |
| 45 | Oxygen sensor or circuit - rich exhaust |
| 46 | Power steering pressure switch (4 cylinder - air-conditioned modules) |
| 46 | Vehicle Anti-Theft System (VATS) |
| 46 | Right to left fueling imbalance (Cadillac) |
| 47 | Air conditioning clutch and cruise circuit |
| 48 | Misfire diagnosis |
| 48 | EGR system fault (cadillac) |
| 51 | PROM, MEM"CAL or ECM problem (3.1L) |
| 52 | CALPAK or ECM problem (3.1L) |
| 53 | System over-voltage (ECM over 17.7 volts) |
| 53 | EGR system (carbureted models) |
| 53 | Distributor signal interrupt (1983 and later Cadillac HT4100) |
| 53 | Alternator voltage out of range |
| 53 | Vehicle anti-theft circuit (5.0L TBI) |
| 53 | EGR fault (3.8L) |
| 54 | Fuel pump circuit (3.1L) |
| 54 | EGR fault (3.8L) |
| 55 | ECM/PCM error (except 5.7L PFI systems, Fuel Lean Monitor 5.7L "F" & "Y" bodies) |
| 55 | Oxygen sensor circuit or ECM |
| 55 | TPS out of range (Cadillac) |
| 55 | Fuel lean monitor (Corvette) |
| 55 | EGR fault (3.8L) |
| 56 | Vacuum sensor circuit |
| 56 | Quad driver B circuit (3.8L) |
| 56 | Anti-theft system (Cadillac) |
| 58 | PASS key fuel enable circuit |
| 58 | Transmission code - TTS high temp. (sensor or signal wire grounded) |
| 59 | Transmission code - TTS low temp. (sensor or signal wire open) |
| 60 | Transmission not in drive (Cadillac) |
| 61 | Oxygen sensor signal faulty |
| 61 | Cruise vent solenoid (3.8L) |
| 61 | Secondary part throttle valve (Corvette) |
| 61 | Air conditioning system performance (5.7L) |
| 62 | Transaxle gear switch signal circuits (3.1L V6 / Quad-4 engines) |
| 62 | Engine oil temperature sensor (5.7L) |
| 62 | Cruise vacuum circuit (3.8L) |
| 63 | MAP sensor voltage high |
| 63 | EGR flow check (3.8L) |
| 63 | Right side oxygen sensor circuit open (5.7L) |
| 64 | EGR flow check (3.8L) |
| 64 | MAP sensor voltage low |
| 64 | Right side oxygen sensor lean (dual sensor models) |
| 65 | EGR flow check (3.8L) |
| 65 | Right side oxygen sensor rich (dual sensor models) |
| 65 | Cruise servo position sensor (3.8L) |
| 65 | Fuel Injection Circuit (Quad-4 engines) |
| 66 | Air conditioning pressure sensor circuit |
| 67 | Air conditioning pressure sensor or clutch circuit (Chevrolet) |
| 67 | Curise switch circuit |
| 68 | Air conditioning relay circuit (Chevrolet) |
| 68 | Cruise system problem |
| 69 | Air conditioning clutch circuit (Chevrolet) |
| 69 | Air conditioning head pressure switch circuit |
| 69 | Transmission code - Torque converter stuck on (4L60-E) |
| 70 | Intermittent TPS (Cadillac) |
| 70 | AC refrigerant pressure sensor circuit (Cheverolet) |
| 71 | Intermittent MAP (Cadillac) |
| 71 | AC evaporator temperature sensor circuit(low temperature) |
| 72 | Gear selector switch (Chevrolet) |
| 72 | Throttle switch circuit (Cadillac) |
| 72 | Transmission code - Vehicle Speed Sensor (VSS) signal loss (4L60-E) |
| 73 | Intermittent coolant sensor (Cadillac) |
| 73 | AC evaporator pressure sensor circuit |
| 74 | Intermittent MAT (Cadillac) |
| 74 | Traction Control System (TCS) circuit voltage low (1995 F-body VIN P) |
| 75 | Intermittent speed sensor (Cadillac) |
| 75 | EGR circuit (1995) |
| 75 | System voltage low (charging system problem) |
| 75 | Transmission system voltage low (1995 F-body VIN P) |
| 79 | Transmission fluid temperature high (4L60-E) |
| 80 | Fuel system rich (Cadillac) |
| 80 | TPS idle learn (Cadillac 4.6L) |
| 80 | Transmission slipping (F-body 3.4L) |
| 81 | Cam reference problem (Cadillac) |
| 81 | Transmission code - QDM solenoid "A" (1st and 2nd gear) current error |
| 82 | Reference signal high (Cadillac) |
| 82 | Transmission code - QDM solenoid "B" (2nd and 3rd gear) current error |
| 83 | Transmission code - QDM torque converter circuit fault (4L80-E) |
| 83 | Reverse Inhibit System (F-body, manual transmission, 5.7L) |
| 85 | Idle throttle angle high (Cadillac 4.6L) |
| 85 | Throttle body service required (Cadillac) |
| 85 | Undefined gear ratio (4L80-E) |
| 85 | PROM error (1995 3.4L) |
| 86 | Transmission code - Low gear ratio (4L80-E) |
| 87 | Transmission code - High gear ratio (4L80-E) |
| 87 | EEPROM error (1995 3.4L) |
| 90 | Transmission TCC solenoid circuit (manual transmission) |
| 91 | Skip shift lamp circuit (1995 3.4L VIN P) |
| 93 | PCS circuit current error (1995 3.4L) |
| 95 | Engine stall detected (Cadillac) |
| 96 | Transmission system voltage low (1995 F-body 3.4L) |
| 97 | VSS output circuit (1995 F-body 3.4L) |
| 98 | Invalid PCM program (1995 F-body 3.4L) |
| 99 | Power management, cruise control system |
| 99 | TACH output circuit (1995 F-body 3.4L VIN P) |
| 99 | Invalid PCM program |
| 107 | PCM / BCM data link problem |
| 108 | PROM checksum mismatch |
| 109 | PCM memory reset (Cadillac) |
| 110 | Generator L-terminal circuit (Cadillac) |
| 112 | EEPROM failure (Cadillac) |
| 131 | Knock sensor failure (Cadillac) |
| 132 | Knock sensor failure (Cadillac) |
Fehlercodelisten 
