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.
1994 Geo Tracker Base, 1.6 U, StandardFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes
- Introduction
- Self-Diagnostic System
- Diagnostic Code Charts (MFI - CALIF. & New YORK)
- Notes
- On-Board Diagnostic (OBD) System Check (MFI CALIF. & New YORK)
- Chart A-1 (MFI CALIF. & New YORK) - No Malfunction Indicator Light (Mil)
- Chart A-2 (MFI CALIF. & New YORK) - Won't Flash Any Codes, Or (Mil) On Steady
- Code 13 (MFI CALIF. & New YORK) -
- Code 14 (MFI CALIF. & New YORK) - Engine Coolant Temperature Sensor, Low Temperature Indicated
- Code 15 (MFI CALIF. & New YORK) - Engine Coolant Temperature Sensor, High Temperature Indicated
- Code 21 (MFI CALIF. & New YORK) - Throttle Position (TP) Sensor, Signal Voltage High
- Code 22 (MFI CALIF. & New YORK) - Throttle Position (TP) Sensor, Signal Voltage Low
- Code 23 (MFI CALIF. & New YORK) - Intake Air Temperature Sensor, Low Temperature Indicated
- Code 24 (MFI CALIF. & New YORK) - Vehicle Speed Sensor
- Code 25 (MFI CALIF. & New YORK) - Intake Air Temperature Sensor, High Temperature Indicated
- Code 33 (MFI CALIF. & New YORK) - Mass Airflow Sensor High Current Input
- Code 34 (MFI CALIF. & New YORK) - Mass Airflow Sensor Low Current Input
- Code 41 (MFI CALIF. & New YORK) - No Ignition Signal
- Code 42 (MFI CALIF. & New YORK) - Camshaft Position Sensor Circuit, No Signal For 3 Seconds
- Code 44 (MFI CALIF. & New YORK) - Idle Switch Open Or MISADJUSTED
- Code 45 (MFI CALIF. & New YORK) - Idle Switch Grounded Or MISADJUSTED
- Code 51 (MFI CALIF. & New YORK) - Exhaust Gas RECIRCULATION (EGR) Circuit
- Code 52 (MFI CALIF. & New YORK) - Fuel System Circuit, Fuel Leakage Detected
- Code 53 (MFI CALIF. & New YORK) - ECM Failure Detected
- Diagnostic Code Charts (TBI - Federal)
- Notes
- On-Board Diagnostic (OBD) System Check - (TBI Federal)
- Chart A-1 (TBI Federal) - No Malfunction Indicator Light (Mil)
- Chart A-2 (TBI Federal) - Won't Flash Any Codes, Or (Mil) On Steady
- Code 13 (TBI Federal) - Heated Oxygen Sensor Circuit, Open Circuit
- Code 14, Engine Coolant Temperature Sensor, Low Temperature Indicated (Tracker - TBI Federal)
- Code 15 (TBI Federal) - Engine Coolant Temperature Sensor, High Temperature Indicated
- Code 21 (TBI Federal) - Throttle Position (TP) Sensor, Signal Voltage High
- Code 22 (TBI Federal) - Throttle Position (TP) Sensor, Signal Voltage Low
- Code 23 (TBI Federal) - Intake Air Temperature Sensor, Low Temperature Indicated
- Code 24 (TBI Federal) - Vehicle Speed Sensor (VSS) Circuit
- Code 25 (TBI Federal) - Intake Air Temperature Sensor, High Temperature Indicated
- Code 31 (TBI Federal) - Manifold Absolute Pressure Sensor, High Voltage - High Vacuum
- Code 32 (TBI Federal) - Manifold Absolute Pressure Sensor, Low Voltage - Low Vacuum
- Code 41 (TBI Federal) - No Ignition Signal
- Code 42 (TBI Federal) - No Camshaft Position Signal For 2 Seconds
- Code 44 (TBI Federal) - Idle Switch Open Or MISADJUSTED
- Code 45 (TBI Federal) - Idle Switch Grounded Or MISADJUSTED
- Code 51 (TBI Federal) - Exhaust Gas RECIRCULATION Circuit
- Code 53 (TBI Federal) - Open Ground Circuit
- 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.