Diag. Code
21
Main Oxygen Sensor and Heater Signal
CIRCUIT DESCRIPTION
The main oxygen sensor is located in the exhaust manifold. It indirectly determines whether the fuel
mixture is rich or lean by detecting the concentration of oxygen present in the exhaust gas.
The main oxygen sensor is provided with a heater. The heater is controlled by the ECU. When the
intake air volume is low (the temperature of the exhaust gas is low) current flows to the heater to heat
the sensor for accurate detection.
Code No.
Diagnosis
Trouble Area
(1) Open or short in heater circuit of main oxygen
sensor for 0.5 sec. or more (HT).
•
Open or short in heater circuit of
main oxygen sensor
•
Main oxygen sensor heater
•
ECU
21
(2) At normal driving speed (below 60 mph and
engine speed is above 1,500 rpm), amplitude
of oxygen sensor signal (OX1) is reduced to
between 0.35–0.70 V continuously for 60
sec. or more
(2 trip detection logic)*
•
Open or short in main oxygen sen-
sor circuit
•
Main oxygen sensor
•
ECU
*: See page
TR–36
–
ENGINE TROUBLESHOOTING
Circuiit Inspection
Содержание 2VZ-FE
Страница 1: ...ENGINE MECHANICAL EM 1 ENGINE MECHANICAL Description Operation ...
Страница 31: ...CYLINDER HEADS COMPONENTS EM 29 ENGINE MECHANICAL Cylinder Heads ...
Страница 63: ...CYLINDER BLOCK REMOVAL OF ENGINE EM 61 ENGINE MECHANICAL Cylinder Block ...
Страница 64: ...EM 62 ENGINE MECHANICAL Cylinder Block ...
Страница 71: ...COMPONENTS EM 69 ENGINE MECHANICAL Cylinder Block ...
Страница 106: ...EFI SYSTEM FI 1 ...
Страница 107: ...DESCRIPTION FI 2 EFI SYSTEM Description ...
Страница 111: ...OPERATION System Circuit FI 4 EFI SYSTEM Operation System Circuit ...
Страница 121: ...FUEL SYSTEM Fuel Pump EFI SYSTEM Fuel System Fuel Pump FI 15 ...
Страница 141: ...Fuel Tank and Lines COMPONENTS EFI SYSTEM Fuel System Fuel Tank and Lines FI 35 ...
Страница 172: ...EXHAUST SYSTEM EXHAUST SYSTEM REPAIR INSTRUCTIONS EX 1 ...
Страница 173: ...EXHAUST PIPES AND HEAT INSULATORS COMPONENTS EX 2 EXHAUST SYSTEM Exhaust Pipes and Heat Insulators ...
Страница 174: ...EMISSION CONTROL SYSTEMS EC 1 ...
Страница 176: ...COMPONENT LAYOUT AND SCHEMATIC DRAWING EMISSION CONTROL SYSTEMS Component Layout and Schematic Drawing EC 3 ...
Страница 186: ...COOLING SYSTEM CO 1 ...
Страница 205: ...LUBRICATION SYSTEM LUBRICATION SYSTEM Description Operation LU 1 ...
Страница 223: ...SERVICE SPECIFICATIONS SPECIFICATIONS TORQUE SPECIFICATIONS LU 18 LUBRICATION SYSTEM ServiceSpecifications ...
Страница 224: ...IGNITION SYSTEM IG 1 ...
Страница 237: ...SERVICE SPECIFICATIONS IG 14 IGNITION SYSTEM ServiceSpecifications ...
Страница 238: ...ENGINE TROUBLESHOOTING TR 1 ...
Страница 268: ...DIAGNOSTIC CHART WIRING DIAGRAM AND ECU CONNECTORS ENGINE TROUBLESHOOTING CircuitInspection TR 31 ...
Страница 285: ...DIAGNOSTIC CHART WIRING DIAGRAM AND ECU CONNECTORS TR 48 ENGINE TROUBLESHOOTING CircuitInspection ...
Страница 292: ...DIAGNOSTIC CHART WIRING DIAGRAM AND ECU CONNECTORS ENGINE TROUBLESHOOTING CircuitInspection TR 55 ...
Страница 301: ...DIAGNOSTIC CHART WIRING DIAGRAM AND ECU CONNECTORS TR 64 ENGINE TROUBLESHOOTING CircuitInspection ...
Страница 315: ...DIAGNOSTIC CHART WIRING DIAGRAM AND ECU CONNECTORS TR 78 ENGINE TROUBLESHOOTING CircuitInspection ...
Страница 320: ...DIAGNOSTIC CHART WIRING DIAGRAM AND ECU CONNECTORS ENGINE TROUBLESHOOTING CircuitInspection TR 83 ...