Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1995 Buick Century CustomFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes - 3.1L
- Introduction
- Self-Diagnostic System
- ECM/Pcm Code Charts
- Notes
- DTC 13: Open Oxygen Sensor Circuit
- DTC 14: Coolant Temp Sensor Signal Voltage Low (Hi Temp Indicated)
- DTC 15: Coolant Temp Sensor Signal Voltage Low
- DTC 21: Throttle Position Sensor Signal Voltage High
- DTC 22: Throttle Position Sensor Signal Voltage Low
- DTC 23: IAT Sensor Signal Voltage High (Low Temp Indicated)
- DTC 24: Vehicle Speed Sensor
- DTC 25: IAT Sensor Signal Voltage Low (High Temp Indicated)
- DTC 33: Map Sensor Signal Voltage High
- DTC 34: Map Sensor Signal Voltage Low
- DTC 35: IAC Idle Speed Error
- DTC 44: Lean Exhaust Indication
- DTC 45: Rich Exhaust Indication
- DTC 55: Pcm Error
- DTC P0101: Mass Air Flow (MAF) Sensor Circuit
- DTC P0112: IAT Sensor Circuit Low Temperature Indicated
- DTC P0113: IAT Sensor Circuit High Temperature
- DTC P0117: Coolant Temp Sensor Low Temp Indicated
- DTC P0118: Coolant Temp Sensor High Temp Indicated
- DTC P0122: Throttle Position Sens Signal Voltage Low
- DTC P0123: Throttle Position Sens Signal Voltage High
- DTC P0131: Heated O2 Sensor Low Signal Voltage (Lean)
- DTC P0132: Heated O2 Sensor High Signal Voltage (Rich)
- DTC P0134: Heated Oxygen Sensor Open Circuit
- DTC P0321: Ignition Control 24X Signal CKT Error
- DTC P0325: Knock Sensor Error (Single Sensor)
- DTC P0341: Camshaft Position Sensor Extra Cam Pulses
- DTC P0342: Camshaft Position Sensor CKT (Loss Of Cam Pulses)
- DTC: P0501/P0502 VSS Circuit
- DTC P0703: TCC Brake Switch Input
- DTC P0705: Transaxle Range SW
- DTC P0712: Transaxle Temp Sensor Low Temp Indicated
- DTC P0713: Transaxle Temp Sensor High Temp Indicated
- DTC P0740: Torque Converter Clutch
- DTC P0755: Trans. Shift Solenoid "B"
- DTC P1350: Ic Circuit Open
- DTC P1361: Ic By-Pass Circuit
- DTC: P1403/P1404/P1405 EGR Error
- DTC P1530: A/C Refrigerant Pressure
- DTC P1550: Cruise Stepper Motor
- DTC P1623: Prom Error
- DTC P1630: System Voltage High/Low
- DTC P1640: QDM "A" Circuit
- DTC P1650: QDM "B" Circuit
- Summary
- Wiring Diagrams
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.