1986 TOYOTA LAND CRUISER catalytic converter

- DIAGNOSTICSAUTOMATIC TRANSMISSION
DI-367
560 Author
: Date
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6. DEFINITION OF TERMS
TermDefinition
Monitor descriptionDescription of what the ECM monitors and how it detects malfunctions (monitoring purpose and its details).
Related DTCsDiagnostic code
Typical enabling condition
Preconditions that allow the ECM to detect malfunctions.
With all preconditions satisfied, the ECM sets the DTC when the monitored value(s) exceeds the malfunction
threshold(s).
Sequence of operation
The priority order that is applied to monitoring, if multiple sensors and components are used to detect the malfunc-
tion.
While another sensor is being monitored, the next sensor or component will not be monitored until the previous
monitoring has concluded.
Required sensor/compo-
nentsThe sensors and components that are used by the ECM to detect malfunctions.
Frequency of operation
The number of times that the ECM checks for malfunctions per driving cycle.
ºOnce per driving cycleº means that the ECM detects malfunction only one time during a single driving cycle.
ºContinuousº means that the ECM detects malfunction every time when enabling condition is met.
DurationThe minimum time that the ECM must sense a continuous deviation in the monitored value(s) before setting a
DTC. This timing begins after the ºtypical enabling conditionsº are met.
Malfunction thresholdsBeyond this value, the ECM will conclude that there is a malfunction and set a DTC.
MIL operation
MIL illumination timing after a defect is detected.
ºImmediatelyº means that the ECM illuminates MIL the instant the ECM determines that there is a malfunction.
º2 driving cycleº means that the ECM illuminates MIL if the same malfunction is detected again in the 2nd driving
cycle.
7. TOYOTA/LEXUS PART AND SYSTEM NAME LIST
This reference list indicates the part names used in this manual along with their definitions.
TOYOTA/LEXUS nameDefinition
Toyota HCAC system, Hydrocarbon adsorptive Catalyst
(HCAC) system, HC adsorptive three-way catalystHC adsorptive three-way catalytic converter
Variable Valve Timing sensor, VVT sensorCamshaft position sensor
Variable valve timing system, VVT systemCamshaft timing control system
Camshaft timing oil control valve, Oil control valve OCV,
VVT, VSVCamshaft timing oil control valve
Variable timing and lift, VVTLCamshaft timing and lift control
Crankshaft position sensor ºAºCrankshaft position sensor
Engine speed sensorCrankshaft position sensor
THAIntake air temperature
Knock control moduleEngine knock control module
Knock sensorEngine knock sensor
Mass or volume air flow circuitMass air flow sensor circuit
Vacuum sensorManifold air pressure sensor
Internal control module, Control module, Engine control
ECU, PCMPower train control module
FC idleDeceleration fuel cut
Idle air control valveIdle speed control
VSV for CCV, Canister close valve VSV for canister controlEvaporative emissions canister vent valve
VSV for EVAP, Vacuum switching valve assembly No. 1,
EVAP VAV, Purge VSVEvaporative emissions canister purge valve
VSV for pressure switching valve, Bypass VSVEvaporative emission pressure switching valve
Vapor pressure sensor, EVAP pressure sensor, Evaporative
emission control system pressure sensorFuel tank pressure sensor
Charcoal canisterEvaporative emissions canister
ORVR systemOn-boad refueling vapor recovery system
Intake manifold runner controlIntake manifold tuning system
Intake manifold runner valve, IMRV, IACV (runner valve)Intake manifold tuning valve
Intake control VSVIntake manifold tuning solenoid valve

P20302
FI7210
A00798
Atmosphere
Housing
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Platinum Electrode
Heater
Coating (Ceramic)
Exhaust Gas CoverIdeal Air-Fuel Mixture
Output Voltage
Richer - Air Fuel Ratio - Leaner
A21040
Reference(Bank 1 Sensor 1 System Drawing) :
ECM
EFI or ECD Relay
EFI or ECD
Fuse No. 1 From
Battery
GroundOX1A
MREL HT1A
Duty
Control Heater
Sensor Heated Oxygen Sensor
EFI or ECD
Fuse No. 2
E2 DI-50
- DIAGNOSTICSENGINE
243 Author
: Date
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CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three-way cata-
lytic converter is used, but for the most efficient use of the three-way catalytic converter, the air-fuel ratio
must be precisely controlled so that it is always close to the stoichiometric air-fuel ratio.
The heated oxygen sensor has the characteristic which its output voltage changes suddenly in the vicinity
of the stoichiometric air-fuel ratio. This characteristic is used to detect the oxygen concentration in the ex-
haust gas and provide the ECM with feedback to control the air-fuel ratio.
When the air-fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the heated
oxygen sensor informs the ECM of the LEAN condition (low voltage, i.e. less than 0.45 V).
When the air-fuel ratio is RICHER than the stoichiometric air-fuel ratio, the oxygen concentration in the ex-
haust gas is reduced and the heated oxygen sensor informs the ECM of the RICH condition (high voltage,
i.e. more than 0.45 V). The ECM judges by the voltage output from the heated oxygen sensor whether the
air-fuel ratio is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the
heated oxygen sensor causes output of abnormal voltage, this disables the ECM for performing an accurate
air-fuel ratio control. The heated oxygen sensors include a heater which heats the zirconia element. The
heater is controlled by the ECM. 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 oxygen concentration detection.
HINT:
The ECM provides a pulse width modulated control circuit to adjust current through the heater. The heated
oxygen sensor heater circuit uses a relay on the B+ side of the circuit.

A20806
Rich
Lean 0.55
0.45
0.40
Oxygen sensor output voltage (V)
PASS
FAILFAIL
FAIL
Pass / Fail definition of voltage malfunction
Time
- DIAGNOSTICSENGINE
DI-107
300 Author
: Date
:
2004 LAND CRUISER (RM1071U)
MONITOR DESCRIPTION
The ECM uses the heated oxygen sensor information to regulate the air-fuel ratio close to a stoichiometric
ratio. This maximizes the catalytic converter's ability to purify the exhaust gas. The sensor detects oxygen
levels in the exhaust gas and sends this signal to the ECM.
The inner surface of the sensor element is exposed to outside air. The outer surface of the sensor element
is exposed to exhaust gas. The sensor element is made of platinum coated zirconia and includes an inte-
grated heating element. The heated oxygen sensor has the characteristic whereby its output voltage
changes suddenly in the vicinity of the stoichiometric air-fuel ratio. The heated oxygen sensor generates
output voltage between 0 V and 1.0 V in response to the oxygen concentration in exhaust gas. When the
output voltage of the heated oxygen sensor is 0.55 V or more, the ECM judges that the air-fuel ratio is RICH.
When it is 0.4 V or less, the ECM judges that the air-fuel ratio is LEAN.
Under normal condition, the output voltage from the heated oxygen sensor alternates RICH and LEAN sides
periodically. If the heated oxygen sensor outputs RICH signal (or LEAN signal) constantly, or if the heated
oxygen sensor cannot output enough voltage to reach the minimum specification, the ECM interprets this
as a malfunction in the heated oxygen sensor and sets a DTC.
MONITOR STRATEGY
P0130Front heated oxygen sensor voltage is constant
at lean side or rich side (Bank 1)
P0150Front heated oxygen sensor voltage is constant
at lean side or rich side (Bank 2)
P2195Front heated oxygen sensor voltage is constant
at lean side (Bank 1)
Related DTCs
P2196Front heated oxygen sensor voltage is constant
at rich side (Bank 1)
P2197Front heated oxygen sensor voltage is constant
at lean side (Bank 2)
P2198Front heated oxygen sensor voltage is constant
at rich side (Bank 2)
Rid / tMain sensors/componentsFront heated oxygen senorRequired sensors/componentsRelated sensors/componentsCrank position sensor, Vehicle speed sensor
Frequency of operationOnce per drive cycle
Duration20 to 36 sec. x (3 times)
MIL operation2 driving cycles
Sequence of operationNone

A20599
0.55
0.40
Oxygen sensor output voltage (V)
Lean to Rich / Rich to Lean time definition
Time Lean to Rich time Rich to Lean time
Rich
Lean Slow slope condition
A20600
Frequency Condition
One Cycle
Rich side frequency
Lean side frequency O2 Sensor Voltage
0.45 V DI-1 18
- DIAGNOSTICSENGINE
311 Author
: Date
:
2004 LAND CRUISER (RM1071U)
MONITOR DESCRIPTION
The ECM uses the heated oxygen sensor information to regulate the air-fuel ratio close to a stoichiometric
ratio. This maximizes the catalytic converter's ability to purify the exhaust gases. The sensor detects oxygen
levels in the exhaust gas and sends this signal to the ECM.
The inner surface of the sensor element is exposed to outside air. The outer surface of the sensor element
is exposed to exhaust gas. The sensor element is made of platinum coated zirconia and includes an inte-
grated heating element. The heated oxygen sensor has the characteristic whereby its output voltage
changes suddenly in the vicinity of the stoichiometric air-fuel ratio. The heated oxygen sensor generates
waveforms of a voltage between 0 V and 1 V in response to the oxygen concentration in exhaust gas. When
the output voltage of the heated oxygen sensor is 0.55 V or more, the ECM judges that the air-fuel ratio is
RICH. When it is 0.40 V or less, the ECM judges that the air-fuel ratio is LEAN.
The ECM monitors the response feature of the heated oxygen sensor. If the response time of the heated
oxygen sensor output status change from RICH to LEAN or vice versa becomes longer, the ECM interprets
this as a malfunction in the heated oxygen sensor and sets a DTC.

A20596
Normal Catalyst
Abnormal Catalyst Waveform of
Heated Oxygen Sensor
(before Catalyst) Waveform of
Heated Oxygen Sensor
(before Catalyst)
Waveform of
Heated Oxygen Sensor
(after Catalyst) Waveform of
Heated Oxygen Sensor
(after Catalyst)
- DIAGNOSTICSENGINE
DI-215
408 Author
: Date
:
DTC P0420 Catalyst System Efficiency Below Threshold
(Bank 1)
DTC P0430 Catalyst System Efficiency Below Threshold
(Bank 2)
MONITOR DESCRIPTION
The vehicle is equipped with two heated oxygen sensors. One is mounted upstream from the TWC (Three-
Way Catalytic) converter (Front Oxygen Sensor, ºsensor 1º), the second is mounted downstream (Rear Oxy-
gen Sensor ºsensor 2º). The catalyst efficiency monitor compares the sensor 1 and sensor 2 signals in order
to calculate TWC ability to store the oxygen.
During normal operation, the TWC stores and releases oxygen as needed. This results in low oxygen varia-
tions in the post TWC exhaust stream as shown below.
DIC2G-01

A20598
Signal Length
Heated Oxygen Sensor Signal Length
Sensor Output
Voltage
Time DI-216
- DIAGNOSTICSENGINE
409 Author
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DTC No.DTC Detecting ConditionTrouble Area
P0420
P0430
After engine and catalyst are warmed up, and while vehicle is
driven within set vehicle and engine speed range, waveform of
heated oxygen sensors have same amplitude
(2 trip detection logic)
Gas leakage on exhaust system

Heated oxygen sensor (bank 1, 2 sensor 1, 2)

Three-way catalytic converter
HINT:

Bank 1 refers to the bank that includes cylinder No.1.

Bank 2 refers to the bank that does not include cylinder No.1.

Sensor 1 refers to the sensor closest to the engine assembly.

Sensor 2 refers to the sensor farthest away from the engine assembly.
MONITOR STRATEGY
RltdDTCP0420Bank 1 catalyst is deterioratedRelated DTCsP0430Bank 2 catalyst is deteriorated
Main sensors/componentsFront and rear heated oxygen sensor
Required sensors/componentsRelated sensors/components
Mass air flow meter, Engine coolant temperature
sensor, Engine speed sensor, Intake air tempera-
ture sensor
Frequency of operationOnce per driving cycle
Duration90 sec.
MIL operation2 driving cycles
Sequence of operationNone

- DIAGNOSTICSENGINE
DI-41
234 Author
: Date
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2004 LAND CRUISER (RM1071U)P0353
(DI-202)
Ignition Coil ºCº Primary/Second-
ary Circuit

Open or short in IGF 2 and IGT 3 circuit from No. 3 ignition
coil with igniter to ECM

No. 3 ignition coil with igniter

Ignition system

ECM

P0354
(DI-202)Ignition Coil ºDº Primary/Second-
ary Circuit

Open or short in IGF 1 and IGT 4 circuit from No. 4 ignition coil
with igniter to ECM

No. 4 ignition coil with igniter

Ignition system

ECM

P0355
(DI-202)Ignition Coil ºEº Primary/Second-
ary Circuit

Open or short in IGF 2 and IGT 5 circuit from No. 5 ignition coil
with igniter to ECM

No. 5 ignition coil with igniter

Ignition system

ECM

P0356
(DI-202)Ignition Coil ºFº Primary/Second-
ary Circuit

Open or short in IGF 1 and IGT 6 circuit from No. 6 ignition coil
with igniter to ECM

No. 6 ignition coil with igniter

Ignition system

ECM

P0357
(DI-202)Ignition Coil ºGº Primary/Second-
ary Circuit

Open or short in IGF 1 and IGT 7 circuit from No. 7 ignition coil
with igniter to ECM

No. 7 ignition coil with igniter

Ignition system

ECM

P0358
(DI-202)Ignition Coil ºHº Primary/Second-
ary Circuit

Open or short in IGF 2 and IGT 8 circuit from No. 8 ignition coil
with igniter to ECM

No. 8 ignition coil with igniter

Ignition system

ECM

P0420
(DI-215)Catalyst System Efficiency Be-
low Threshold (Bank 1)
Gas leakage on exhaust system

Heated oxygen sensor (bank 1 sensor 1, 2)

Three-way catalytic converter

P0430
(DI-215)Catalyst System Efficiency Be-
low Threshold (Bank 2)
Gas leakage on exhaust system

Heated oxygen sensor (bank 2 sensor 1, 2)

Three-way catalytic converter

P0441
(DI-222)Evaporative Emission Control
System Incorrect Purge Flow

Vacuum hose cracks, holed, blocked, damaged or discon-
nected ((1), (2), (3), (4), (5), (6), (7), (8) and (9) in Fig. 1)

Fuel tank cap incorrectly installed

Fuel tank cap cracked or damaged

Open or short in vapor pressure sensor circuit

Vapor pressure sensor

Open or short in VSV circuit for EVAP

EVAP VSV

Open or short in VSV circuit for CCV

CCV

Open or short in VSV circuit for pressure switching valve

Pressure switching valve

Fuel tank cracked, holed or damaged

Charcoal canister cracked, holed or damaged

ECM


DI-18
- DIAGNOSTICSENGINE
211 Author
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TC/TE1
[Test Details]
Connect the TC and TE1.
ON or OFFSwitch to the same state as
the connection between
terminal TC and TE1.
FC IDL PROHBT
[Test Details]
Control the idle fuel cut prohibit.
ON or OFF
-
9. DEFINITION OF TERMS
TermDefinition
Monitor descriptionDescription of what the ECM monitors and how it detects malfunctions (monitoring purpose and its details).
Related DTCsDiagnostic code
Typical enabling condition
Preconditions that allow the ECM to detect malfunctions.
With all preconditions satisfied, the ECM sets the DTC when the monitored value(s) exceeds the malfunction
threshold(s).
Sequence of operation
The priority order that is applied to monitoring, if multiple sensors and components are used to detect the malfunc-
tion.
When a sensor is being monitored, the next sensor or component will not be monitored until the sensor monitoring
is finished.
Required sensor/compo-
nentsThe sensors and components that are used by the ECM to detect malfunctions.
Frequency of operation
The number of times that the ECM checks for malfunctions per driving cycle.
ºOnce per driving cycleº means that the ECM detects the malfunction only one time during a single driving cycle.
ºContinuousº means that the ECM detects malfunction every time an enabling condition is met.
DurationThe minimum time that the ECM must sense a continuous deviation in the monitored value(s) before setting a
DTC. This timing begins after the ºtypical enabling conditionsº are met.
Malfunction thresholdsBeyond this value, the ECM will conclude that there is a malfunction and set a DTC.
MIL operation
MIL illumination timing after a defect is detected.
ºImmediatelyº means that the ECM illuminates MIL the instant the ECM determines that there is a malfunction.
º2 driving cycleº means that the ECM illuminates MIL if the same malfunction is detected again in the 2nd driving
cycle.
10. TOYOTA/LEXUS PART AND SYSTEM NAME LIST
This reference list indicates the part names used in this manual along with their definitions.
TOYOTA/LEXUS nameDefinition
Toyota HCAC system, Hydro-carbon Adsorptive Catalyst
(HCAC) system, HC adsorptive three-way catalystHC adsorptive three-way catalytic converter
Variable Valve Timing sensor, VVT sensorCamshaft position sensor
Variable valve timing system, VVT systemCamshaft timing control system
Camshaft timing oil control valve, Oil control valve, OCV,
VVT, VSVCamshaft timing oil control valve
Variable timing and lift, VVTLCamshaft timing and lift control
Crankshaft position sensor ºAºCrankshaft position sensor
Engine speed sensorCrankshaft position sensor
THAIntake air temperature
Knock control moduleEngine knock control module
Knock sensorEngine knock sensor
Mass or volume air flow circuitMass air flow sensor circuit
Vacuum sensorManifold air pressure sensor
Internal control module, Control module, Engine control
ECU, PCMPower train control module
FC idleDeceleration fuel cut