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.
1993 Pontiac LeMans VLFACTORY OEM SERVICE PROCEDURE
Trouble Code Definition
FAULT CODES
| Code | Component | Circuit Fault |
|---|---|---|
| 12 | Self-Diagnostic Operation | KOEO (Normal Condition) |
| 13 | O2 Sensor | Open Circuit |
| 14 | Coolant Temp. Sensor | High Temperature Signal |
| 15 | Coolant Temp. Sensor | Low Temperature Signal |
| 21 | Throttle Position Sensor | Signal Voltage High |
| 22 | Throttle Position Sensor | Signal Voltage Low |
| 24 | Vehicle Speed Sensor | Signal Fault |
| 32 | EGR System | System Failure |
| 33 | MAP Sensor | Signal Voltage High (Low Vacuum) |
| 34 | MAP Sensor | Signal Voltage Low (High Vacuum) |
| 42 | Ignition Control (IC) Circuit | Signal Fault |
| 44 | O2 Sensor Circuit | Lean Exhaust Signal |
| 45 | O2 Sensor Circuit | Rich Exhaust Signal |
| 51 | Faulty MEM-CAL | Circuit Fault |
| 53 | System Voltage | Overvoltage Signal |
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.