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.
1996 Geo Prizm Base, StandardFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes
- Introduction
- Self-Diagnostic System
- Circuit Tests
- Notes
- Circuit Test B2-1 - Inoperative Malfunction Indicator Light
- Circuit Test B2-2 - Malfunction Indicator Light On Steady
- Circuit Test B2-4 - No Communication From Data Link Connector
- DTC P0105 - Manifold Absolute Pressure Sensor Circuit
- DTC P0106 - Map Sensor System Performance
- DTC P0110 - Intake Air Temperature Sensor Circuit
- DTC P0115 - Engine Coolant Temperature Sensor Circuit
- DTC P0116 - ECT Sensor Circuit Performance
- DTC P0120 - Throttle Position (TP) Sensor Circuit
- DTC P0121 - Throttle Position (TP) Sensor Circuit Performance
- DTC P0125 - Excessive Time To Enter Closed Loop
- DTC P0130 - Oxygen Sensor 1 (O2S1) Circuit
- DTC P0133 - Oxygen Sensor 1 (O2S1) Slow Response
- DTC P0136 - Heated Oxygen Sensor 2 (Ho2S2) Circuit
- DTC P0141 - Heated Oxygen Sensor 2 (Ho2S2) Heater Circuit
- DTC P0171 - Fuel Trim System Lean
- DTC P0172 - Fuel Trim System Rich
- DTC P0300 - Engine Misfire Detected
- DTCS P0301, P0302, P0303, & P0304 - Cylinders No. 1-4 Misfire Detected
- DTC P0325 - Knock Sensor (KS) Circuit
- DTC P0335 - Crankshaft Position (CKP) Sensor Circuit
- DTC P0340 - Camshaft Position (CMP) Sensor Circuit
- DTC P0401 - EGR Flow Insufficient
- DTC P0402 - Exhaust Gas RECIRCULATION (EGR) Flow Excessive
- DTC P0420 - Three-Way Catalyst (TWC) System Efficiency Low
- DTC P0500 - Vehicle Speed Sensor (VSS) Circuit
- DTC P0505 - Idle Control System
- DTC P1300 - Ignition Control Module (IGNITOR) Circuit
- DTC P1335 - Crankshaft Position (CKP) Sensor Circuit
- DTC P1500 - Starter Signal Circuit
- DTC P1600 - Pcm Battery
- Summary
Factory Service Tools
Use the Manual With the Right Hardware
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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.