| 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) |