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 Lexus SC 300 AutomaticFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes
- Introduction
- Notes
- 1993 Terminology
- Self-Diagnostic System
- Retrieving Codes
- Diagnostic Trouble Codes
- Notes
- MIL Flashes 2 Times Every Second
- Code 12
- Code 13
- Code 14
- Code 16
- Code 21 (Except GS300 Calif.)
- Code 21 (GS300 Calif.)
- Code 22
- Code 24
- Code 25
- Code 26 (Calif.)
- Code 27 (Calif.)
- Code 28 (Except GS300 Calif.)
- Code 28 (GS300 Calif.)
- Code 31 (ES300)
- Code 31 (GS300 & SC300)
- Code 32 (ES300)
- Code 35 (GS300 & SC300)
- Code 41 (GS300 & SC300)
- Code 41 (ES300)
- Code 42
- Code 43
- Code 47 (GS300 & SC300 With Traction Control)
- Code 51
- Code 52
- Code 53
- Code 55
- Code 71 (Calif.)
- Code 78 (GS300 & SC300)
- Malfunction Indicator Light (Mil) Does Not Flash
- Test Preparation
- Clearing Codes
- ECM Location
- Trouble Code Identification
- Diagnostic Code Charts
- Code 12 - Rpm Signal Circuit
- Code 13 - Rpm Signal Circuit
- Code 14 - Ignition Signal Circuit
- Code 16 - ECT Control Signal Malfunction
- Codes 21 & 28 - Main Oxygen Sensor Circuit (Es300 & SC300)
- Codes 21 & 28 - Main Oxygen Sensor Circuit (GS300 Ca)
- Code 22 - Coolant Temperature Sensor Signal Circuit
- Code 24 - Intake Air Temperature Sensor Signal Circuit
- Codes 25 & 26 - Air/Fuel Ratio Malfunction (Es300)
- Codes 25 & 26 - Air/Fuel Ratio Malfunction (GS300 & SC300)
- Code 27 - Sub-Oxygen Sensor Circuit (Es300 Ca)
- Code 27 - Sub-Oxygen Sensor Circuit (GS300 & SC300 Ca)
- Code 31 - Low Airflow Meter Voltage (Es300)
- Code 31 - Low Airflow Meter Voltage (GS300 & SC300)
- Code 32 - High Airflow Meter Voltage (Es300)
- Code 35 - Barometric Pressure Sensor Circuit (GS300 & SC300)
- Code 41 - Throttle Position Sensor (TPS) Circuit (Es300)
- Codes 41 & 47 - Throttle Position Sensor (TPS) Signal (GS300 & SC300)
- Code 42 - Vehicle Speed Sensor (VSS) Signal Circuit
- Code 43 - Starter Signal
- Code 51 - Switch Condition Signal (Es300)
- Code 51 - Switch Condition Signal (GS300 & SC300)
- Codes 52, 53 & 55 - Knock Sensor Signal
- Code 71 - EGR System Malfunction (Es300 Ca)
- Code 71 - EGR System Malfunction (GS300 & SC300 Ca)
- Code 78 - Fuel Pump Control Circuit (GS300 & SC300)
- Summary
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.