1992 Lexus SC 300 AutomaticFACTORY OEM SERVICE PROCEDURE

Trouble Code Definition

CODE IDENTIFICATION (1)

Code (2) Fault Circuit
12  No Distributor Signal After 2 Seconds Cranking RPM Signal
13  No Distributor Signal At More Than 1000 RPM RPM Signal
14  No IGF Signal For 6 IGT Signals Ignition
16  No Link Between CPU & ECT CPU (3) ECT Control
21  Fixed Oxygen Sensor Voltage Main Oxygen Sensor (Left Bank ES300, Front Side SC300)
22  Open Or Short In Circuit For More Than .5 Second Water Temperature Sensor
24  Open Or Short In Circuit For More Than .5 Second Intake Air Temperature Sensor
25  Sensor Voltage Low For More Than 90 Seconds Air/Fuel Ratio Lean Malfunction
26  Difference In Air/Fuel Ratio Of Oxygen Sensors Air/Fuel Ratio Rich Malfunction
27 (4) Low Sensor Voltage Under Rich Condition Sub-Oxygen Sensor
28  Fixed Oxygen Sensor Voltage Main Oxygen Sensor (Right Bank ES300, Rear Side SC300)
31  Low Airflow Meter Voltage For More Than .5 Second Airflow Meter
32  High Airflow Meter Voltage For More Than .5 Second Airflow Meter (ES300 Only)
35  Open Or Short In Circuit For More Than .5 Second High Altitude Compensator (HAC) Sensor
41  Open Or Short In Circuit For More Than .5 Second Throttle Position Sensor
42  No Vehicle Speed Signal For 8 Seconds With 3000 RPM Vehicle Speed Sensor
43 (5) No Starter Signal Starter
47 (6) Open Or Short In Circuit For More Than .5 Second Sub-Throttle Position Sensor
51  Idle Switch Off After 3 Seconds Running, Neutral Switch Off In "D, R, 2, 1" Or A/C Switch On Switch Condition
52  No Knock Sensor Signal For 4 Crankshaft Revolutions At More Than 1600 RPM Knock Sensor (Left Bank ES300, Front Side SC300)
53  No ECU Knock Signal Knock Control
55  No Knock Sensor Signal For 4 Crankshaft Revolutions At More Than 1600 RPM Knock Sensor (Right Bank ES300, Rear Side SC300)
71 (4) Low EGR Temperature EGR System Malfunction
78  Open Or Short In Circuit At Less Than 1000 RPM Fuel Pump Control (SC300)
(1) If diagnostic code displayed is not shown in this table, ECU is faulty.
(2) All diagnostic codes except Codes 16, 43, 51 and 53 will remain in ECU memory until erased.
(3) Electronically Controlled Transaxle (ECT).
(4) ES300 California models and SC300 Federal models only.
(5) Code 43 sets if vehicle is push-started (normal).
(6) Code 47 for SC300 vehicles with traction control only.
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  • • 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.

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