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 Geo Storm Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Trouble Code Definitions
FAULT CODE IDENTIFICATION
| Code | Circuit Affected | Probable Cause | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 13 (1) | Non-Heated Oxygen Sensor | Open Circuit | ||||||||
| 13 (2) | Heated Oxygen Sensor | Open Circuit | ||||||||
| 14 | Coolant Temperature Sensor | High/Low Temp. Indicated | ||||||||
| 21 | Throttle Position Sensor | Signal Voltage High/Low | ||||||||
| 23 | Intake Air Temp. Sensor | High/Low Temp. Indicated | ||||||||
| 24 | Vehicle Speed Sensor | Incorrect Signal Voltage | ||||||||
| 32 (3) | EGR System | EGR Failure | ||||||||
| 33 | MAP Sensor | Signal Voltage Low/High Vacuum | ||||||||
| 42 | Ignition Control Circuit Error | Open/Short Circuit | ||||||||
| 44 (4) | Oxygen Sensor | Lean Exhaust Indicated | ||||||||
| 45 (4) | Oxygen Sensor | Rich Exhaust Indicated | ||||||||
| 51 | ECM Failure | ECM Failed Or PROM Failure | ||||||||
|
||||||||||
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.