LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2003 >> CTS Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Trouble Code Definitions
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Trouble Code Definitions

NOTE: DTCs are retrieved using a Tech 2® scan tool, or other OBD-II compatible scan tool connected to OBD-II 16-pin Data Link Connector (DLC).
DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTC Description (1) Code Type
BXXXX (2) Body Control Systems Malfunction N/A
CXXXX (2) Chassis Control Systems Malfunction N/A
P0030  HO2S Heater Control Circuit - Bank 1 Sensor 1 B
P0031  HO2S Heater Circuit Low - Bank 1 Sensor 1 B
P0032  HO2S Heater Circuit High - Bank 1 Sensor 1 B
P0036  HO2S Heater Control Circuit - Bank 1 Sensor 2 B
P0037  HO2S Heater Circuit Low - Bank 1 Sensor 2 B
P0038  HO2S Heater Circuit High - Bank 1 Sensor 2 B
P0050  HO2S Heater Control Circuit - Bank 2 Sensor 1 B
P0051  HO2S Heater Circuit Low - Bank 2 Sensor 1 B
P0052  HO2S Heater Circuit High - Bank 2 Sensor 1 B
P0056  HO2S Heater Control Circuit - Bank 2 Sensor 2 B
P0057  HO2S Heater Circuit Low - Bank 2 Sensor 2 B
P0058  HO2S Heater Circuit High - Bank 2 Sensor 2 B
P0101  Mass Airflow Sensor System Performance B
P0102  Mass Airflow Sensor Circuit Low Frequency B
P0103  Mass Airflow Sensor Circuit High Frequency B
P0112  Intake Air Temperature Sensor Circuit Low Voltage B
P0113  Intake Air Temperature Sensor Circuit High Voltage B
P0116  Engine Coolant Temperature Sensor Circuit Performance B
P0117  Engine Coolant Temperature Sensor Circuit Low Voltage B
P0118  Engine Coolant Temperature Sensor Circuit High Voltage B
P0121  Throttle Position Sensor Circuit Insufficient Activity B
P0122  Throttle Position Sensor Circuit Voltage Low B
P0123  Throttle Position Sensor Circuit Voltage High B
P0125  Engine Coolant Temperature Excessive Time To Reach Closed Loop B
P0128  Engine Coolant Thermostat B
P0130  HO2S Bank 1 Sensor 1 Circuit B
P0131  HO2S Bank 1 Sensor 1 Circuit - Low Voltage B
P0132  HO2S Bank 1 Sensor 1 Circuit - High Voltage B
P0133  HO2S Bank 1 Sensor 1 - Slow Response B
P0134  HO2S Bank 1 Sensor 1 - Insufficient Activity B
P0135  HO2S Bank 1 Sensor 1 - Heater Performance B
P0136  HO2S Bank 1 Sensor 2 Circuit B
P0137  HO2S Bank 1 Sensor 2 Circuit - Low Voltage B
P0138  HO2S Bank 1 Sensor 2 Circuit - High Voltage B
P0140  HO2S Bank 1 Sensor 2 Circuit - Insufficient Activity B
P0141  HO2S Bank 1 Sensor 2 - Heater Performance B
P0150  HO2S Bank 2 Sensor 1 Circuit B
P0151  HO2S Bank 2 Sensor 1 Circuit - Low Voltage B
P0152  HO2S Bank 2 Sensor 1 Circuit - High Voltage B
P0153  HO2S Bank 2 Sensor 1 Circuit - Slow Response B
P0154  HO2S Bank 2 Sensor 1 - Insufficient Activity B
P0155  HO2S Bank 2 Sensor 1 - Heater Performance B
P0156  HO2S Bank 2 Sensor 2 Circuit B
P0157  HO2S Bank 2 Sensor 2 Circuit - Low Voltage B
P0158  HO2S Bank 2 Sensor 2 Circuit - High Voltage B
P0160  HO2S Bank 2 Sensor 2 Circuit - Insufficient Activity B
P0161  HO2S Bank 2 Sensor 2 - Heater Performance B
P0171  Fuel Trim System Lean - Bank 1 B
P0172  Fuel Trim System Rich - Bank 1 B
P0174  Fuel Trim System Lean - Bank 2 B
P0175  Fuel Trim System Rich - Bank 2 B
P0201-P0206  Injector Control Circuit B
P0218 (3) Transaxle Overtemperature C
P0219  Engine Overspeed Condition C
P0221  Throttle Position Sensors No. 1 & 2 - Mismatch B
P0222  Throttle Position Sensor No. 2 - Circuit Voltage Low B
P0223  Throttle Position Sensor No. 2 - Circuit Voltage High B
P0261  Cylinder No. 1 Injector Circuit Low B
P0262  Cylinder No. 1 Injector Circuit High B
P0264  Cylinder No. 2 Injector Circuit Low B
P0265  Cylinder No. 2 Injector Circuit High B
P0267  Cylinder No. 3 Injector Circuit Low B
P0268  Cylinder No. 3 Injector Circuit High B
P0270  Cylinder No. 4 Injector Circuit Low B
P0271  Cylinder No. 4 Injector Circuit High B
P0273  Cylinder No. 5 Injector Circuit Low B
P0274  Cylinder No. 5 Injector Circuit High B
P0276  Cylinder No. 6 Injector Circuit Low B
P0277  Cylinder No. 6 Injector Circuit High B
P0300  Engine Misfire Detected A
P0301  Cylinder No. 1 Misfire Detected A
P0302  Cylinder No. 2 Misfire Detected A
P0303  Cylinder No. 3 Misfire Detected A
P0304  Cylinder No. 4 Misfire Detected A
P0305  Cylinder No. 5 Misfire Detected A
P0306  Cylinder No. 6 Misfire Detected A
P0313  Misfire Detected With Low Fuel C
P0318  Loss Of Communication - Rough Road Data C
P0324  Knock Control System Error B
P0327  Knock Sensor Circuit Low Input - Bank 1 B
P0328  Knock Sensor Circuit High Input - Bank 1 B
P0332  Knock Sensor Circuit Low Input - Bank 2 B
P0333  Knock Sensor Circuit High Input - Bank 2 B
P0335  No Crankshaft Position Sensor Reference Pulses B
P0336  Crankshaft Position Sensor Range/Performance B
P0337  Crankshaft Position Sensor Circuit - Low Frequency B
P0338  Crankshaft Position Sensor Circuit - High Frequency B
P0341  Camshaft Position Sensor Circuit Performance B
P0342  Camshaft Position Sensor Circuit - Signal Low B
P0343  Camshaft Position Sensor Circuit - Signal High B
P0420  Catalyst System Low Efficiency - Bank 1 B
P0430  Catalyst System Low Efficiency - Bank 2 B
P0440  EVAP System - Large Leak Detected B
P0442  EVAP System - Small Leak Detected B
P0443  EVAP Purge Control Valve Circuit Malfunction B
P0444  EVAP Purge Control Valve Circuit Open B
P0445  EVAP Purge Control Valve Circuit Shorted B
P0446  EVAP Canister Vent Blocked Or Restricted B
P0447  EVAP Vent Valve Control Circuit Open B
P0448  EVAP Vent Valve Control Circuit Shorted B
P0449  EVAP Canister Vent Solenoid Control Circuit B
P0451  EVAP Pressure Sensor Range/Performance B
P0452  EVAP Pressure Sensor Circuit - Low Voltage B
P0453  EVAP Pressure Sensor Circuit - High Voltage B
P0461 (4) Fuel Level Sensor Circuit Performance C
P0462 (4) Fuel Level Sensor Circuit - Low Voltage C
P0463 (4) Fuel Level Sensor Circuit - High Voltage C
P0480 (5) Low Speed Cooling Fan Relay Control Circuit Open C
P0481 (5) High Speed Cooling Fan Relay Control Circuit Open C
P0496  EVAP System High Purge Flow B
P0500 (3) Very Low Vehicle Speed Detected With Vehicle In Motion B
P0504 (2) Status Of Stop Light Switch Input And TCC Brake Switch/Cruise Control Input To ECM Do Not Match C
P0506  Idle Speed Low B
P0507  Idle Speed High B
P0532 (6) A/C Pressure Sensor Signal Voltage Low C
P0533 (6) A/C Pressure Sensor Signal Voltage High C
P0560 (7) System Voltage C
P0562 (7) System Voltage Low C
P0563 (7) System Voltage High C
P0601  Control Module Read Only Memory A
P0602  Control Module Not Programmed C
P0603  Control Module Long Term Memory Reset A
P0604  Control Module Random Access Memory A
P0605  ECM Read Only Memory Error A
P0606  Control Module Internal Performance A
P0607  Control Module Performance A
P0610  Control Module Vehicle Options Error C
P0615 (8) Starter Relay Control Circuit C
P0616 (8) Improper Voltage Level Detected On Starter Relay Output Circuit C
P0617 (8) Improper Voltage Level Detected On Starter Relay Output Circuit C
P0625 (7) Generator Field Duty Cycle Signal Circuit Low C
P0626 (7) Generator Field Duty Cycle Signal Circuit High C
P0628  Fuel Pump Relay Control Circuit Low C
P0629  Fuel Pump Relay Control Circuit High C
P0638  Throttle Actuator Control Range/Performance A
P0645 (6) A/C Compressor Clutch Relay Control Circuit Open C
P0646 (6) A/C Compressor Clutch Relay Control Circuit Short To Ground C
P0647 (6) A/C Compressor Clutch Relay Control Circuit Short To Voltage C
P0650  Malfunction Indicator Light Control Circuit C
P0660  Intake Manifold Tuning Valve Control Circuit Malfunction C
P0661  Intake Manifold Tuning Valve Control Circuit Low C
P0662  Intake Manifold Tuning Valve Control Circuit High C
P0691 (5) Low Speed Cooling Fan Relay Control Circuit Short To Ground C
P0692 (5) Low Speed Cooling Fan Relay Control Circuit Short To Voltage C
P0693 (5) High Speed Cooling Fan Relay Control Circuit Short To Ground C
P0694 (5) High Speed Cooling Fan Relay Control Circuit Short To Voltage C
P0700  Transmission Control System (MIL Request) A
P0704 (9) 20 Or More Gear Changes Detected With Less Than 6 Clutch Pedal Transitions C
P0711 (3) Transmission Fluid Temperature Sensor Circuit Performance C
P0712 (3) Transmission Fluid Temperature Sensor Circuit - Low Input C
P0713 (3) Transmission Fluid Temperature Sensor Circuit - High Input C
P0716 (3) Input Speed Sensor Circuit Intermittent B
P0717 (3) Input Speed Sensor Circuit - Low Input B
P0719 (3) Brake Switch Circuit - Low Input C
P0724 (3) Brake Switch Circuit - High Input C
P0731 (3) Incorrect 1st Gear Ratio C
P0732 (3) Incorrect 2nd Gear Ratio C
P0733 (3) Incorrect 3rd Gear Ratio C
P0734 (3) Incorrect 4th Gear Ratio C
P0741 (3) Torque Converter Clutch Circuit Inoperative - Stuck Off B
P0742 (3) Torque Converter Clutch Circuit Inoperative - Stuck On B
P0748 (3) Pressure Control Solenoid Electrical Malfunction C
P0751 (3) 1-2 Shift Solenoid Valve Performance B
P0752 (3) 1-2 Shift Solenoid Valve Performance B
P0756 (3) 2-3 Shift Solenoid Performance A
P0757 (3) 2-3 Shift Solenoid Performance A
P0850 (2) Park/Neutral Switch Circuit Low/High C
P0856 (10) Traction Control Input Signal C
P1172  Secondary Fuel Level Sensor - Lack Of Variation C
P1551  Incorrect At-Rest Throttle Position B
P1600  ECM Battery N/A
P1621  ECM Memory B
P1627  ECM Memory N/A
P1629 (11) Fuel Enable Password Not Received C
P1630 (11) Theft Deterrent System - ECM In Learn Mode C
P1631 (11) Theft Deterrent System - Password Incorrect C
P1644 (10) Delivered Torque Signal Voltage Invalid C
P1680  ECM Memory N/A
P1681  ECM Memory N/A
P1683  ECM Memory N/A
P1689 (10) Delivered Torque Signal Voltage Invalid C
P1820 (3) Internal Mode Switch Circuit "A" B
P1822 (3) Internal Mode Switch Circuit "B" B
P1823 (3) Internal Mode Switch Circuit "P" B
P1825 (3) Internal Mode Switch - Invalid Range N/A
P1842 (3) 1-2 Shift Solenoid Circuit Low Voltage B
P1843 (3) 1-2 Shift Solenoid Circuit High Voltage B
P1845  Engine Torque Limitation C
P1847 (3) 2-3 Shift Solenoid Circuit High Voltage A
P1868 (3) Transmission Fluid Life C
P2008  Intake Manifold Runner Control - Control Circuit Low C
P2009  Intake Manifold Runner Control - Control Circuit Low C
P2010  Intake Manifold Runner Control - Control Circuit High C
P2066 (4) Secondary Fuel Level No Change Detected Over Distance C
P2067 (4) Secondary Fuel Level Sender Signal Lower Than Normal C
P2068 (4) Secondary Fuel Level Sender Signal Higher Than Normal C
P2096  Fuel Trim Bias Commanded Lean Longer Than Expected - Bank 1 Sensor 1 B
P2097  Fuel Trim Bias Commanded Rich Longer Than Expected - Bank 1 Sensor 1 B
P2098  Fuel Trim Bias Commanded Lean Longer Than Expected - Bank 2 Sensor 1 B
P2099  Fuel Trim Bias Commanded Rich Longer Than Expected - Bank 2 Sensor 1 B
P2100  Throttle Control System - Excessive Pulse Width Modulation Detected A
P2101  Minimum Throttle Position Not Detected A
P2105  Throttle Control System - Out Of Controllable Limit A
P2107  Throttle Control System - Not Operating In Desired Range C
P2119  Throttle Control System - Not Returning To Rest Position Within Calibrated Time A
P2122  Accelerator Pedal Position Sensor No. 1 - Signal Voltage Low A
P2123  Accelerator Pedal Position Sensor No. 1 - Signal Voltage High A
P2127  Accelerator Pedal Position Sensor No. 2 - Signal Voltage Low A
P2128  Accelerator Pedal Position Sensor No. 2 - Signal Voltage High A
P2135  Throttle Position Sensors No. 1 & 2 Signal Voltage Difference More Than Predicted C
P2138  Accelerator Pedal Position Sensors No. 1 & 2 Signal Voltage Difference More Than Predicted A
P2176  Minimum Throttle Position Not Detected B
P2500 (7) Generator Turn-On Signal Circuit Low Voltage C
P2501 (7) Generator Turn-On Signal Circuit High Voltage C
P2610  Control Module Random Access Memory A
UXXXX (2) Communication Malfunction N/A
(1) For description of the different code types, see CODE TYPES  under SELF-DIAGNOSTIC SYSTEM.
(2) Diagnose DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
(3) See appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.
(4) See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.
(5) See appropriate ELECTRIC COOLING FANS article in ENGINE COOLING.
(6) See appropriate A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
(7) See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.
(8) See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
(9) See appropriate DIAGNOSIS article in MANUAL TRANSMISSIONS.
(10) See appropriate ANTI-LOCK article in BRAKES.
(11) See appropriate ANTI-THEFT SYSTEMS article in ACCESSORIES & EQUIPMENT.
scientia non olet · About LEMON Manuals