LEMON Manuals
: Even more car manuals for everyone: 1960-2025
Home
>>
Lexus
>>
1992
>>
LS 400
>>
Repair and Diagnosis
>>
Engine Performance
>>
System
>>
Engine Controls - System/Component Tests
April 5, 2026:
LEMON Manuals is launched!
Read the announcement.
Engine Controls - System/Component Tests
Expand All (for easy ctrl-f)
Collapse All
Introduction
Computerized Engine Controls
Notes
Control Unit
Ground Circuits (LS400)
Engine Sensors & Switches
Airflow Meter
Airflow Meter Air Temperature Sensor Resistance
Neutral Start Switch
Throttle Position Sensor (TPS)
Relays
Circuit Opening Relay
EFI Main Relay
Starter Relay
Fuel System
Fuel Delivery
Fuel Control
Notes
Fuel Cut System
Fuel Injectors
Fuel Pressure Control System
Cold Start System
Idle Control System
Idle Speed Control (ISC) Valve
Ignition System
Notes
Ignition Coils
Emission Systems & Sub-Systems
Exhaust Gas RECIRCULATION (EGR)
EGR System
EGR Vacuum Modulator Check
Vacuum Switching Valve
Fuel Evaporation
EVAP Canister
Bimetallic Vacuum Switching Valve
EVAP Vacuum Control Valve
Positive Crankcase Ventilation (PCV)
PCV Valve
Throttle Controls
Dashpot
Miscellaneous Controls
Notes
Cooling Fan
Electronic Cooling Fan System
A/C Pressure Switch
Coolant Temperature Sensor
Coolant Temperature Switch
Engine Main Relay & Cooling Fan Relay No. 3
Cooling Fan Relay No. 1 & No. 2
Cooling Fan Motors No. 1 & No. 2
Circuit Diagnostic Charts
Notes
EFI Ecu Terminal Identification
Neutral Start Switch Circuit
Ecu Power Source Circuit
Back-Up Power Source Circuit
Injector Circuit
Cold Start Injector Circuit
Fuel System Circuit
Fuel Pressure Control Vacuum Switch Valve Circuit
Terminal Te1 & Te2 Circuit Diagnosis
A/C Compressor Circuit