exhaust TOYOTA CAMRY 1999 Service Owner's Guide

A00479
Engine Speed
3,000 rpm
Idling
IG SW OFF
Warmed up
3 min. or so
CheckTime (a)(c) (d)
(b) 2,000 rpm
2 sec. 2 sec.
DI±120
± DIAGNOSTICSENGINE (5S±FE)
355 Author: Date:
CONFIRMATION ENGINE RACING PATTERN
(a) Connect the OBD II scan tool or TOYOTA hand±held tester to the DLC3.
(b) Start the engine and warm it up with all accessories switched OFF until water temp. is stable.
(c) Race the engine at 2,500 ~ 3,000 rpm for about 3 min.
(d) When racing the engine at 3,000 rpm for 2 sec. and 2,000 rpm for 2 sec. alternately, check the wave-
form of the heated oxygen sensor (bank 1 sensor 2).
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
1 Are there any other codes (besides DTC P0420) being output?
YES Go to relevant DTC chart.
NO
2 Check gas leakage on exhaust system.
NG Repair or replace.
OK

DI07B±07
± DIAGNOSTICSENGINE (1MZ±FE)
DI±211
446 Author: Date:
DIAGNOSTIC TROUBLE CODE CHART
1. SAE CONTROLLED
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument
or other factors.
If a malfunction code is displayed during the DTC check in check mode, check the circuit for that code listed
in the table below. For details of each code, turn to the page referred to under the ''See page '' for the respec-
tive ''DTC No.'' in the DTC chart.
DTC No.
(See Page)Detection ItemTrouble AreaMIL*1Memory
P0100
(DI±222)Mass Air Flow Circuit
MalfunctionOpen or short in mass air flow meter circuit
Mass air flow meter
ECM

P0101
(DI±227)Mass Air Flow Circuit
Range/Performance
Problem
Mass air flow meter
P0110
(DI±228)Intake Air Temp. Circuit
MalfunctionOpen or short in intake air temp. sensor circuit
Intake air temp. sensor (built into mass air flow meter)
ECM

P0115
(DI±233)Engine Coolant Temp. Circuit
MalfunctionOpen or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM

P0116
(DI±237)Engine Coolant Temp. Circuit
Range/Performance ProblemEngine coolant temp. sensor
Cooling system
P0120
(DI±239)Throttle/Pedal Position
Sensor/Switch ºAº Circuit
MalfunctionOpen or short in throttle position sensor circuit
Throttle position sensor
ECM

P0121
(DI±243)Throttle/Pedal Position
Sensor/Switch ºAº Circuit
Range/Performance Problem
Throttle position sensor
*2
P0125
(DI±244)
Insufficient Coolant Temp. for
Closed Loop Fuel Control
(Except California Spec.)
Fuel system
Injector
Ignition system
Gas leakage on exhaust system
Open or short in heated oxygen sensor circuit
(bank 1, 2 sensor 1)
Heated oxygen sensor (bank 1, 2 sensor 1)
ECM

*3
P0125
(DI±249)
Insufficient Coolant Temp. for
Closed Loop Fuel Control
(Only for California Spec.)
Fuel system
Injector
Ignition system
Gas leakage on exhaust system
Open or short in A/F sensor circuit (bank 1, 2 sensor 1)
A/F sensor (bank 1, 2 sensor 1)
ECM

*2
P0130
(DI±255)Heated Oxygen Sensor Circuit
Malfunction (Bank 1 Sensor 1)Heated oxygen sensor
Fuel trim malfunction
*1: 


MIL lights up
*
2: Except California specification vehicles
*
3: Only for California specification vehicle

DI±212
± DIAGNOSTICSENGINE (1MZ±FE)
447 Author: Date:
DTC No.
(See Page)Detection ItemTrouble AreaMILMemory
*2
P0133
(DI±259)
Heated Oxygen Sensor Circuit
Slow Response
(Bank 1 Sensor 1)Heated oxygen sensor
Fuel trim malfunction
*2
P0135
(DI±263)
Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 1)Open or short in heater circuit of heated oxygen sensor
Heated oxygen sensor heater
ECM

P0136
(DI±265)Heated Oxygen Sensor Circuit
Malfunction
(Bank 1 Sensor 2)
Heated oxygen sensor
P0141
(DI±263)Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 2)
Same as DTC No. P0135*1
*3
P0150
(DI±255)
Heated Oxygen Sensor
Circuit Malfunction
(Bank 2 Sensor 1)
Same as DTC No. P0130*1
*3
P0153
(DI±259)
Heated Oxygen Sensor
Circuit Slow Response
(Bank 2 Sensor 1)Same as DTC No. P0133
Fuel trim malfunction*1
*3
P0155
(DI±263)Heated Oxygen Sensor
Circuit Malfunction
(Bank 2 Sensor 1)
Same as DTC No. P0135*1
*3
P0171
(DI±272)System too Lean
(Fuel Trim)
(Except California Spec.)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Heated oxygen sensor (bank 1, 2 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
Gas leakage on exhaust system
*1
*3
P0172
(DI±272)System too Rich
(Fuel Trim)
(Except California Spec.)
Fuel line pressure
Injector leak, blockage
Heated oxygen sensor (bank 1, 2 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
Gas leakage on exhaust system
*1
*4
P0171
(DI±267)System too Lean
(Fuel Trim)
(Only for California Spec.)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
A/F sensor (bank 1, 2 sensor 1)
Gas leakage on exhaust system
*1
*4
P0172
(DI±267)System too rich
(Fuel Trim)
(Only for California Spec.)
Fuel line pressure
Injector leak, blockage
Heated oxygen sensor malfunction
Mass air flow meter
Engine coolant temp. sensor
A/F sensor (bank 1, 2 sensor 1)
Gas leakage on exhaust system
*1
*1: MIL lights up
*2: MIL light up or blinking
*3: Except California specification vehicles
*4: Only for California specification vehicle

± DIAGNOSTICSENGINE (1MZ±FE)
DI±213
448 Author: Date:
DTC No.
(See Page)Detection ItemTrouble AreaMILMemory
P0300
(DI±276)Random/Multiple Cylinder
Misfire DetectedIgnition system
Injector
Fuel line pressure
EGR
P0301
P0302
P0303
P0304
P0305
P0306
(DI±276)Misfire Detected
± Cylinder 1
± Cylinder 2
± Cylinder 3
± Cylinder 4
± Cylinder 5
± Cylinder 6
EGR
Compression pressure
Valve clearance not to specification
Valve timing
Mass air flow meter
Engine coolant temp. sensor
Open or short engine wire
Connector connection
ECM
*2
P0325
(DI±283)Knock Sensor 1 Circuit
MalfunctionOpen or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM
*1
P0330
(DI±283)Knock Sensor 2 Circuit
MalfunctionOpen or short in knock sensor 2 circuit
Knock sensor 2 (looseness)
ECM
*1
P0335
(DI±287)Crankshaft Position Sensor
ºAº Circuit Malfunction
Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Starter
ECM
*1
P0340
(DI±290)Camshaft Position Sensor
Circuit Malfunction
Open or short in camshaft position sensor circuit
Camshaft position sensor
Starter
ECM
*1
P0401
(DI±292)Exhaust Gas Recirculation
Flow Insufficient Detected
EGR valve (stuck closed)
Open or short in EGR gas temp. sensor circuit
EGR gas temp. sensor
Open in VSV circuit for EGR
VSV for EGR
Vacuum control valve
Vacuum hose disconnected or blocked
ECM
*1
P0402
(DI±302)Exhaust Gas Recirculation
Flow Excessive Detected
EGR valve stuck open
VSV for EGR open malfunction
Short in VSV circuit for EGR
Open or short in EGR valve position sensor circuit
EGR valve position sensor
ECM
*1
*3
P0420
(DI±305)Catalyst System Efficiency
Below Threshold
(Except California Spec.)Three±way catalytic converter
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
*2
*4
P0420
(DI±308)Catalyst System Efficiency
Below Threshold
(Only for California Spec.)
Three±way catalytic converter
Open or short in heated oxygen sensor (bank 1, sensor 2)
circuit
Heated oxygen sensor (bank 1, sensor 2)
Open or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
*2
*1: MIL lights up
*2: MIL lights up on U.S.A and Canadian specification vehicles
*3: Except California specification vehicles
*4: Only for California specification vehicle

P21242 FI7210
A00027
Atmosphere
CoverIdeal Air±Fuel Mixture
Air Fuel Ratio
RicherLeaner
Exhaust GasFlange
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Platium Electrode
Heater
Coating(Ceramic)
Output Voltage
DI±244
± DIAGNOSTICSENGINE (1MZ±FE)
479 Author: Date:
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control (Except California Spec.)
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three±way
catalytic 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 oxygen sensor has the characteristic whereby 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 exhaust
gas and provide feedback to the computer for control of the air±fuel ratio.
When the air±fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the oxygen
sensor informs the ECM of the LEAN condition (small electromotive force: < 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 oxygen sensor informs the ECM of the RICH condition (large electromotive
force: > 0.45 V). The ECM judges by the electromotive force from the oxygen sensor whether the air±fuel
ratio is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sen-
sor causes output of abnormal electromotive force, the ECM is unable to perform accurate air±fuel ratio con-
trol.
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.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After engine is warmed up, heated oxygen sensor (bank 1, 2
sensor 1) output does not indicate RICH ( 0.45 V ) even
once when conditions (a), (b), (c) and (d) continue for at least
2 min.:
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40
SPD and 100 km/h (25
SPD and
62 mph)
(c) Throttle valve does not fully closed
(d) 140 sec. or more after starting engine
Fuel system

Injector

Ignition system

Gas leakage on exhaust system

Open or short in heated oxygen sensors (bank 1, 2 sensor 1)
circuit

Heated oxygen sensors (bank 1, 2 sensor 1)

ECM
DI07M±08

DI±248
± DIAGNOSTICSENGINE (1MZ±FE)
483 Author: Date:
9 Check gas leakage on exhaust system.
NG Repair or replace.
OK
Replace heated oxygen sensors
(bank 1, 2 sensor 1).
10 Perform confirmation driving pattern (See page DI±255).
Go
11 Is there DTC P0125 being output again ?
YES Check and replace ECM
(See page IN±31).
NO
12 Did vehicle runs out of fuel in the past ?
NO Check for intermittent problems
(See page DI±197).
NO
DTC P0125 is caused by running out of fuel.

A00477
CoverAtmosphere
Platinum
Electrode
Solid Electrolyte
(Zirconia Element)
Platinum
Electrode
Heater
Coating (Ceramic)
Exhaust Gas
(V)
4.0
3.8
3.6
3.4
3.2
3.0
2.8
2.6
17
Air±Fuel Ratio
2.4
16 15 12 1413 1918ECM Monitored
A/F Sensor Voltage
± DIAGNOSTICSENGINE (1MZ±FE)
DI±249
484 Author: Date:
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control (Only for California Spec.)
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three±way
catalytic 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 A/F sensor has the characteristic that provides output voltage
* approximately proportional to the existing
air±fuel ratio. The A/F sensor output voltage
* is used to provide feedback for the ECM to control the air±fuel
ratio.
By the A/F sensor output, the ECM can determine the deviation amount from the stoichiometric air±fuel ratio
and control the proper injection time immediately. If the A/F sensor is malfunctioning, ECM is unable to per-
form accurate air±fuel ratio control.
The A/F sensor is equipped with a heater which heats the zirconia element. The heater is controlled by the
ECM. When the intake air volume is low (the temp. of the exhaust gas is low), current flows to the heater
to heat the sensor for accurate oxygen concentration detection.
*: The voltage value changes at the inside of the ECM only.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After engine is warmed up, A/F sensor output* does not
change when conditions (a), (b) and (c) continue for at least
1.5 min.
*: Output value changes at inside of ECM only.
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40 ~ 100 km/h (25 ~ 62 mph)
(c) Throttle valve does not fully closed
(d) After starting engine
140 sec
Fuel system

Injector

Ignition system

Gas leakage on exhaust system

Open or short in A/F sensor circuit (bank 1, 2 sensor 1)

A/F sensors (bank 1, 2 sensor 1)

ECM
DI07M±09

DI±254
± DIAGNOSTICSENGINE (1MZ±FE)
489 Author: Date:
9 Check gas leakage on exhaust system.
NG Repair or replace
OK
Replace A/F sensors (bank1, 2 sensor1).
10 Perform confirmation driving pattern (See page DI±340).
Go
11 Is there DTC P0125 being output again ?
YES Check and replace ECM
(See page IN±31).
NO
12 Did vehicle runs out of fuel in the past ?
NO Check for intermittent problems
(See page DI±197).
YES
DTC P0125 is caused by running out of fuel.

± DIAGNOSTICSENGINE (1MZ±FE)
DI±267
502 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
(Only for California Spec.)
DTC P0172 System too Rich (Fuel Trim)
(Only for California Spec.)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short±term fuel trim and long±term fuel trim.
Short±term fuel trim is the short±term fuel compensation used to maintain the air±fuel ratio at its ideal
theoretical value.
The signal from the A/F sensor is approximately proportional to the existing air±fuel ratio, and ECM compar-
ing it with the ideal theoretical value, the ECM reduces fuel volume immediately if the air±fuel ratio is rich
and increases fuel volume if it is lean.
Long±term fuel trim compensates the deviation from the central value of the short±term fuel trim stored up
by each engine tolerance, and the deviation from the central value due to the passage of time and changes
of using environment.
If both the short±term fuel trim and long±term fuel trim exceed a certain value, it is detected as a malfunction
and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on RICH side
(2 trip detection logic)

Gas leakage on exhaust system

Air intake (hose loose)

Fuel line pressure

Injector blockage

Mass air flow meter

Engine coolant temp. sensor

A/F sensors (bank 1, 2 sensor 1)
P0172
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on LEAN side
(2 trip detection logic)

Gas leakage on exhaust system

Fuel line pressure

Injector leak, blockage

Mass air flow meter

Engine coolant temp. sensor

A/F sensors (bank 1, 2 sensor 1)
DI07R±05

± DIAGNOSTICSENGINE (1MZ±FE)
DI±269
504 Author: Date:
4 Check for spark and ignition (See page IG±1).
NG Repair or replace.
OK
5 Check fuel pressure (See page SF±21).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page SF±1).
OK
6 Check gas leakage on exhaust system.
NG Repair or replace.
OK