1992 Lexus LS 400FACTORY OEM SERVICE PROCEDURE

Trouble Code Definition

CODE IDENTIFICATION

Code (1) Fault Circuit
12  No Distributor Signal After 2 Seconds Cranking RPM Signal
13  No Distributor Signal More Than 1000 RPM RPM Signal
14
LS400  No IGF1 Signal From Ignitor No. 1 For 8 IGT Signals Ignition
SC400  No IGF1 Signal From Ignitor No. 1 For 8 IGT Signals Ignition
15
LS400  No IGF2 Signal From Ignitor No. 2 For 8 IGT Signals Ignition
SC400  No IGF2 Signal From Ignitor No. 2 For 8 IGT Signals Ignition
16  Normal signal is not output from ECT CPU ECT (2)
17 (3) Open Or Short In No. 1 Cam Sensor Circuit No. 1 Cam Sensor Circuit
18 (3) Open Or Short In No. 2 Cam Sensor Circuit No. 2 Cam Sensor Circuit
21  Fixed Oxygen Sensor Voltage Or Main Oxygen Sensor (Left Bank) Open Or Short In Heater Circuit
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
LS400  Low Sensor Voltage Under Rich Condition Sub-Oxygen Sensor (Left Bank)
SC400  Low Sensor Voltage Under Rich Condition Sub-Oxygen Sensor (Left Bank)
28  Fixed Oxygen Sensor Voltage Or Main Oxygen Sensor (Right Bank) Open Or Short In Heater Circuit
29
LS400  Low Sensor Voltage Under Rich Condition Sub-Oxygen Sensor (Right Bank)
SC400  Low Sensor Voltage Under Rich Condition Sub-Oxygen Sensor (Right Bank)
31  No Airflow Meter Signal To ECU For 2 Seconds Airflow Meter
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 (4) No Vehicle Speed Signal For 8 Seconds With 3000 RPM Vehicle Speed Sensor
43 (5) No Starter Signal Starter
47  Open Or Short In Circuit For More Than .5 Second Sub-Throttle Position Sensor
51
LS400  Idle Switch Off After 3 Seconds Running, Neutral Switch Off In "D, R, 2, 1" Or A/C Switch On Switch Condition
SC400  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 3 Crankshaft Revolutions At More Than 1600 RPM Knock Sensor No. 1
53  No ECU Knock Signal Knock Control
55  No Knock Sensor Signal For 3 Crankshaft Revolutions At More Than 1600 RPM Knock Sensor No. 2
71
LS400  Low EGR Temperature EGR System Malfunction
SC400 (6) Low EGR Temperature EGR System Malfunction
78 (4) Open Or Short In Circuit At Less Than 1000 RPM Fuel Pump Control
(1) All diagnostic codes except Codes 16, 17, 18, 43, 51 and 53 will remain in ECU memory until erased.
(2) Electronically Controlled Transaxle (ECT).
(3) LS400 models only.
(4) SC400 models only.
(5) Code 43 sets if vehicle is push-started (normal).
(6) SC400 Federal models only.
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