Navigating the complexities of vehicle diagnostics can be daunting, especially when dealing with older systems. For Cadillac owners with classic models, understanding the Cadillac Obd1 Codes List is essential for troubleshooting and maintaining their vehicles. OBD1, or On-Board Diagnostics first generation, was the precursor to the standardized OBD2 system and is found in many Cadillac models from the early years of automotive computerization. This guide provides a detailed list of Cadillac OBD1 diagnostic trouble codes, helping you understand what these codes mean and how they can assist in diagnosing potential issues.
This comprehensive list is designed to serve as a valuable resource for Cadillac owners, DIY mechanics, and automotive enthusiasts alike. By understanding these codes, you can gain valuable insights into your vehicle’s health and potentially address issues before they escalate into more significant problems. Please remember that while this list provides a strong starting point, professional diagnostic equipment and expertise are often necessary for accurate diagnosis and repair.
Instrument Panel Cluster (IPC) Codes
The Instrument Panel Cluster (IPC) is responsible for displaying vital information to the driver. OBD1 codes related to the IPC can indicate issues with the gauges, indicators, and overall cluster functionality.
- I022: Panel Dimming Switch Pot Circuit
- I027: PRND321 switch failure
- I032: Loss of ABS/TCS Data
- I033: Loss of Supplemental Inflatable Restraint Data
- I034: Loss of Powertrain Control Module Data
- I037: Loss of Air Conditioning Programmer Data
- I039: Loss of Road Sensing Suspension Data
- I041: Battery Voltage Too Low
- I042: Battery Voltage Too High
- I052: Keep Alive Memory Error
- I056: Instrument Panel Cluster EEPROM Error
Antilock Brake System (ABS) Codes
The Antilock Brake System (ABS) is a crucial safety system. These OBD1 codes relate to various components within the ABS, including wheel speed sensors, valve solenoids, and the electronic control module.
- T021: RF Wheel Speed Sensor Fault
- T022: RF Wheel Speed Sensor Frequency Error
- T023: RF Wheel Speed Sensor Continuity Fault
- T025: LF Wheel Speed Sensor Fault
- T026: LF Wheel Speed Sensor Frequency Error
- T027: LF Wheel Speed Sensor Continuity Fault
- T028: Wheel Speed Sensor Frequency Error
- T031: RR Wheel Speed Sensor Fault
- T032: RR Wheel Speed Sensor Frequency Error
- T033: RR Wheel Speed Sensor Continuity Fault
- T035: LR Wheel Speed Sensor Fault
- T036: LR Wheel Speed Sensor Frequency Error
- T037: LR Wheel Speed Sensor Continuity Fault
- T041: RF ABS Valve Solenoid Fault
- T044: RF TCS Pilot Valve Fault
- T045: LF ABS Valve Solenoid Fault
- T048: LF TCS Pilot Valve Fault
- T051: RR ABS Valve Solenoid Fault
- T055: LR Valve Solenoid Valve Fault (TCS) / Rear Valve Solenoid Valve Fault (Non – TCS)
- T061: Motor Pump Circuit Fault
- T063: Valve Relay Fault
- T067: Brake Light Switch Fault
- T071: Electronic Brake and TCS (EBTCM/EBCM) Internal Fault
- T072: Serial Data Link Fault
- T073: PCM – EBTCM/EBCM Pulse Width Modulation Signal Fault
- T083: Brake Fluid Level Low
Supplemental Inflatable Restraint (SIR) Codes
The Supplemental Inflatable Restraint (SIR) system, or airbags, is another critical safety feature. These codes indicate potential problems within the airbag system, ranging from sensor issues to circuit faults.
- R014: Dual Pole Arming Sensor Disconnected
- R015: Passenger Initiator Circuit Resistance High
- R016: Passenger Initiator Circuit Resistance Low
- R017: Passenger Initiator Circuit Open
- R018: Discriminating Sensor Interconnect Open
- R019: Passenger Initiator Circuit Voltage High
- R021: Driver Initiator Circuit Resistance High
- R022: Driver Initiator Circuit Resistance Low
- R023: Driver Initiator Circuit Voltage High
- R024: Initiator Circuit Voltage Low
- R025: Initiator Circuit Short to Ignition
- R026: Driver Initiator Circuit Open
- R028: Current Sink Or Source Failure
- R031: Driver Loop Energy Reserve Feed Open
- R034: Dual Pole Arming Sensor Ignition Feed Open
- R035: Discriminating Sensor Open or Missing
- R036: Passenger Loop Energy Reserve Feed Open
- R042: Loop Energy Reserve Voltage Low
- R043: Driver Source Feed Low
- R044: Passenger Source Feed Low
- R051: Frontal Crash Detected
- R052: Data Area Full
- R053: Driver Side Low High Resistance
- R054: Passenger Side Low High Resistance
- R055: DERM Incompatibility
- R061: SIR Indicator Circuit Failure
- R062: Redundant SIR Indicator Circuit Failure
- R071: Internal Diagnostic Energy Reserve Module Fault
- R075: Internal DERM Fault
- R081: Driver Ignition Diode Open
- R082: Passenger Ignition Diode Open
- R083: Driver Reserve Diode Shorted
- R084: Passenger Reserve Diode Shorted
Air Conditioning Programmer (ACP) Codes
For Cadillac models equipped with automatic climate control, the Air Conditioning Programmer (ACP) manages the HVAC system. These OBD1 codes can pinpoint issues with sensors, actuators, and refrigerant levels.
- A010: Outside Temperature Sensor Circuit
- A011: High Side Temperature Sensor Circuit
- A012: Low Side Temperature Sensor Circuit
- A013: In-Car Temperature Sensor Circuit
- A015: Sun Load Sensor Circuit
- A037: Loss of Instrument Panel Cluster Data
- A040: Air Mix Valve (Door) Circuit Problem
- A046: Low Refrigerant Charge
- A047: Low Refrigerant Charge
- A048: Low Refrigerant Pressure
- A049: HVAC – Coolant Temperature Too High
- A050: HVAC – Coolant Temperature Too High
- A052: Keep alive memory error
Traction Control System (TCS) Codes
The Traction Control System (TCS) helps maintain vehicle stability during acceleration and slippery conditions. OBD1 codes for the TCS often overlap with ABS codes as they share components, but some codes are specific to TCS functionality.
- T021: RF Wheel Speed Sensor Fault
- T022: RF Wheel Speed Sensor Frequency Error
- T023: RF Wheel Speed Sensor Continuity Fault
- T025: LF Wheel Speed Sensor Fault
- T026: LF Wheel Speed Sensor Frequency Error
- T027: LF Wheel Speed Sensor Continuity Fault
- T028: Wheel Speed Sensor Frequency Error
- T031: RR Wheel Speed Sensor Fault
- T032: RR Wheel Speed Sensor Frequency Error
- T033: RR Wheel Speed Sensor Continuity Fault
- T035: LR Wheel Speed Sensor Fault
- T036: LR Wheel Speed Sensor Frequency Error
- T037: LR Wheel Speed Sensor Continuity Fault
- T041: RF ABS Valve Solenoid Fault
- T044: RF TCS Pilot Valve Fault
- T045: LF ABS Valve Solenoid Fault
- T048: LF TCS Pilot Valve Fault
- T051: RR ABS Valve Solenoid Fault
- T055: LR Valve Solenoid Valve Fault (TCS)
- T061: Motor Pump Circuit Fault
- T063: Valve Relay Fault
- T067: Brake Light Switch Fault (TCS Equipped Vehicles Only)
- T071: Electronic Brake and TCS (EBTCM/EBCM) Internal Fault
- T072: Serial Data Link Fault
- T073: PCM – EBTCM/EBCM Pulse Width Modulation Signal Fault
- T083: Brake Fluid Level Low
Road Sensing Suspension (RSS) Codes
Cadillac’s Road Sensing Suspension (RSS) system, designed for enhanced ride quality and handling, has its own set of OBD1 codes. These codes relate to damper solenoids, position sensors, accelerometers, and the electronic level control system.
- S010: Left Front Damper Solenoid Valve Short to B+
- S011: Left Front Damper Solenoid Valve Short to Ground/Open
- S015: Right Front Damper Solenoid Valve Short to B+
- S016: Right Front Damper Solenoid Valve Short to Ground/Open
- S020: Left Rear Damper Solenoid Valve Short to B+
- S021: Left Rear Damper Solenoid Valve Short to Ground/Open
- S025: Right Rear Damper Solenoid Valve Short to B+
- S026: Right Rear Damper Solenoid Valve Short to Ground/Open
- S030: Speed Sensitive Steering Fault
- S035: Electronic Level Control Compressor Short to B+
- S036: Electronic Level Control Compressor Short to Ground/Open
- S037: Electronic Level Control Exhaust Valve Short to B+
- S038: Electronic Level Control Exhaust Valve Short to Ground/Open
- S043: Speed Signal Fault
- S044: Lift or Dive Signal Fault
- S050: Road Sensing Suspension Module Fault
- S055: Resistor Module Short to Ground/Open
- S060: Left Front Position Sensor Fault
- S061: Right Front Position Sensor Fault
- S062: Left Rear Position Sensor Fault
- S063: Right Rear Position Sensor Fault
- S064: Left Front Position Sensor Overcurrent
- S065: Right Front Position Sensor Overcurrent
- S066: Left Rear Position Sensor Overcurrent
- S067: Right Rear Position Sensor Overcurrent
- S070: Left Front Accelerometer Fault
- S071: Right Front Accelerometer Fault
- S072: Left Rear Accelerometer Fault
- S073: Right Rear Accelerometer Fault
- S074: Left Front Accelerometer Overcurrent
- S075: Right Front Accelerometer Overcurrent
- S076: Left Rear Accelerometer Overcurrent
- S077: Right Rear Accelerometer Overcurrent
Powertrain (PCM) Codes (Engine/Transmission)
The Powertrain Control Module (PCM) is the brain of the engine and transmission management system. These OBD1 codes are crucial for diagnosing engine performance, fuel delivery, ignition, and transmission issues. Note that for 1992 models, “P” codes might be replaced with “E” codes, but the description remains the same.
- P000 / E000 (*): Cruise Servo Apply Problem
- P012 / E012 (*): No Distributor Signal
- P013 / E013 (*): Right Oxygen Sensor Not Ready
- P014 / E014 (*): Shorted Coolant Temp Sensor
- P015 / E015 (*): Open Coolant Temp Sensor Signal
- P016 / E016 (*): Voltage Out of Range [ALL SOL]
- P017 / E017 (*): Left Oxygen Sensor not ready
- P019 / E019 (*): Shorted Fuel Pump Circuit
- P020 / E020 (*): Open Fuel Pump Circuit
- P021 / E021 (*): Shorted TPS Signal [VCC]
- P022 / E022 (*): Open TPS Signal [VCC]
- P023 / E023 (*): EST Signal problem [EGR]
- P024 / E024 (*): Vehicle Speed Sensor signal to TCC
- P025 / E025 (*): (Ignition Control Module) 24x Reference Low Indicator
- P026 / E026 (*): Shorted Throttle Signal Switch
- P027 / E027 (*): Open throttle signal switch
- P029 / E029 (*): Transaxle Shift ‘B’ solenoid problem (1st, 3rd, 4th gear)
- P030 / E030 (*): ISC RPM out of range
- P031 / E031 (*): Shorted MAP Sensor
- P032 / E032 (*): Open MAP Sensor Signal
- P034 / E034 (*): MAP Sensor Signal Out of Range
- P036 / E036 (*): EGR valve pintle position out of range
- P037 / E037 (*): Shorted MAT Sensor Signal
- P038 / E038 (*): Open MAT Sensor Signal
- P039 / E039 (*): Torque Converter Clutch (VCC) Engagement Problem
- P040 / E040 (*): Power steering Pressure switch open
- P041 / E041 (*): No Cam reference signal from ignition control module / Cam Sensor Signal Problem
- P042 / E042 (*): Left Oxygen Sensor Signal Lean
- P043 / E043 (*): Left Oxygen Sensor Signal Rich
- P044 / E044 (*): Right Oxygen Sensor Signal Lean
- P045 / E045 (*): Right Oxygen Sensor Signal Rich
- P046 / E046 (*): Right to Left Bank Fueling Difference
- P047 / E047 (*): IPC – PCM Data Problem
- P048 / E048 (*): EGR system Problem
- P051 / E051 (*): MEM-CAL Error
- P052 / E052 (*): PCM Memory Reset
- P053 / E053 (*): Distributor Signal Interrupt
- P055 / E055 (*): Closed Throttle Angle Out of Range
- P056 / E056 (*): Transmission Input Speed Sensor
- P058 / E058 (*): PASSKey Control Problem
- P059 / E059 (*): Transmission Input speed sensor
- P060 / E060 (*): Cruise-Transaxle Not in Drive
- P061 / E061 (*): Cruise – Vent Solenoid Problem
- P062 / E062 (*): Cruise – Vacuum Solenoid Problem
- P063 / E063 (*): Set Vs. Vehicle Speed Difference
- P064 / E064 (*): Cruise – Vehicle Acceleration Too High
- P065 / E065 (*): Cruise – SPS Failure
- P066 / E066 (*): Cruise – RPM Out of Range
- P067 / E067 (*): Cruise Switch shorted at Enable
- P068 / E068 (*): Cruise Command Problem (servo out of range)
- P070 / E070 (*): Intermittent TPS Signal
- P071 / E071 (*): Intermittent MAP Signal
- P073 / E073 (*): Intermittent Coolant Sensor Signal
- P074 / E074 (*): Intermittent MAT Signal
- P075 / E075 (*): Intermittent VSS Signal
- P076 / E076 (*): Transmission Pressuse Solenoid
- P078 / E078 (*): (This code is missing a description in the original list)
- P080 / E080 (*): Fuel System Rich
- P083 / E083 (*): Crankshaft to Ignition Module Failure
- P085 / E085 (*): Idle Throttle Angle Too High
- P086 / E086 (*): Undefined Gear Ratio (Trans Pressure Control)
- P089 / E089 (*): Long Shift and Maximum Adapt (Trans. Pressure Control)
- P090 / E090 (*): VCC Brake Switch Input Problem / TCC Brake Switch Input Circuit Problem
- P091 / E091 (*): PRNDL Switch Problem (transaxle range switch problem)
- P092 / E092 (*): Heated Windshield Request Problem / Traction Control System PWM Link Failure
- P094 / E094 (*): Transaxle Shift “A” Solenoid Problem (Vehicle Speed Sensor)
- P095 / E095 (*): Engine Stall Detected
- P096 / E096 (*): Torque Converter Overstress
- P097 / E097 (*): High RPM P/N to D/R Shift
- P098 / E098 (*): High RPM P/N to D/R Shift Under ISC
- P099 / E099 (*): Cruise Control Servo Applied, Not in Cruise
- P103 / E103 (*): Open Brake Booster Vacuum Sensor
- P105 / E105 (*): Brake Booster Vacuum Too Low
- P109 / E109 (*): Keep Alive Memory (KAM) Reset
- P110 / E110 (*): Generator L-terminal Circuit Problem
- P117 / E117 (*): Open/Short Solenoids/Solenoid Wiring (Transmission)
- P119 / E119 (*): Open or Shorted Fuel Injector
- P132 / E132 (*): Knock Sensor Circuitry Failure
- P137 / E137 (*): Loss of ABS/TCS Data
(*) for the 1992 model year only, the “Pxxx” (Powertrain) is replaced by an “Exxx” (Engine), but the description remains unchanged.
PCM Data Displays Description
Beyond trouble codes, the OBD1 system in Cadillacs also allows access to live data parameters through the PCM. These data displays can be invaluable for diagnosing intermittent issues or monitoring sensor readings in real-time. Accessing PCM data displays typically involves using a scan tool capable of reading OBDI systems and navigating to the data display function.
Here’s a list of common PCM data parameters available for viewing:
- PD01: TPS (Throttle Position Sensor)
- PD02: Manifold Absolute Pressure Sensor in Kilo Pascals (kPa)
- PD03: Barometric Pressure in kPa
- PD04: Engine Coolant Temperature (ECT) sensor in degrees Celsius
- PD05: Intake Air Temperature (IAT) sensor in degrees Celsius
- PD07: EGR Pintle Position
- PD08: Spark Advance in degrees Before Top Dead Center (BTDC)
- PD09: Ignition Ground Voltage
- PD10: Fuel Pump Feedback Voltage
- PD11: Engine Speed in revolutions per minute (rpm)
- PD12: Vehicle Speed in miles per hour (mph)
- PD13: Pintle Position
- PD15: Ignition 1 Voltage
- PD16: PCM Output Fault Status A
- PD17: PCM Output Fault Status B
- PD30: Front Bank Injector Pulse Width in milliseconds (ms)
- PD31: Rear Bank Injector Pulse Width in milliseconds (ms)
- PD32: Front Oxygen Sensor Voltage
- PD33: Rear Oxygen Sensor Voltage
- PD34: Front Oxygen Sensor Cross Counts
- PD35: Rear Oxygen Sensor Cross Counts
- PD36: Front Short Term Fuel Trim
- PD37: Rear Short Term Fuel Trim
- PD38: Front Long Term Fuel Trim
- PD39: Rear Long Term Fuel Trim
- PD40: Knock Sensor Spark Retard in degrees
- PD41: Knock Sensor
- PD42: Octane Level of Fuel will display 0, 87, 90, or 93
- PD69: Cruise Lash
- PD70: Cruise Control Feedback
- PD71: Transaxle Pressure Switch
- PD72: Transaxle Input Speed in rpm
- PD73: Torque Converter Slip Speed in rpm
- PD74: TPC Solenoid Current
- PD75: Current ER
- PD76: Transaxle Gear Ratio
- PD77: Transaxle Oil Temperature in degrees Celsius
- PD78: Transaxle Shift Adapt in pounds per square inch (psi)
- PD80: Transaxle Garage Shift Adapt in seconds
- PD81: Torque Converter Clutch (TCC) Solenoid Duty Cycle in percent
- PD82: Transaxle Shift Time in seconds
- PD83: Non-drive Wheel Speed in kph
- PD84: Brake Booster Vacuum in kPa
- PD97: PROM Calibration-Transaxle
- PD98: Ignition Cycles
- PD99: PROM Calibration-Engine
Conclusion
This Cadillac OBD1 codes list provides a valuable starting point for diagnosing issues with your classic Cadillac. Understanding these codes can empower you to communicate more effectively with your mechanic, perform DIY repairs if you are experienced, or simply gain a better understanding of your vehicle’s systems.
Remember, while reading OBD1 codes is a helpful diagnostic step, it is not a substitute for professional diagnosis. If you are unsure about interpreting these codes or performing repairs, always consult a qualified automotive technician. They will have the expertise and equipment to accurately diagnose and repair your Cadillac, ensuring its continued performance and reliability. This list is intended for informational purposes and should be used responsibly in conjunction with professional guidance when needed.
