TOYOTA CAMRY 2000 Service Repair Manual

± DIAGNOSTICSENGINE (5S±FE)
DI±71
306 Author: Date:
DTC P0133 Heated Oxygen Sensor Circuit Slow Re-
sponse (Bank 1 Sensor 1) (Ex. CA Spec.)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Except California Spec.)) on
page DI±55.
DTC No.DTC Detecting ConditionTrouble Area
P0133
Response time for heated oxygen sensor's voltage output to
change from rich to lean, or from lean to rich, is 1 sec. or more
during idling after engine is warmed up
(2 trip detection logic)

Heated oxygen sensor

Fuel trim malfunction
HINT:
Sensor 1 refers to the sensor closer to the engine body.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scantool. 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 P0133) being output?
YES Go to relevant DTC chart.
NO
DI4NF±01

P18349
DI±72
± DIAGNOSTICSENGINE (5S±FE)
307 Author: Date:
2 Check output voltage of heated oxygen sensor during idling.
PREPARATION:
Warm up the heated oxygen sensor the engine at 2,500 rpm for approx. 90 sec.
CHECK:
Use the OBD II scan tool or TOYOTA hand±held tester to read the output voltage of the heated oxygen sen-
sor during idling.
OK:
Heated oxygen sensor output voltage:
Alternates repeatedly between less than 0.4 V and more than 0.55 V (See the following table).
OK Go to step 8.
NG
3 Check for open and short in harness and connector between ECM and oxygen
sensor (See page IN±31).
NG Repair or replace harness or connector.
OK

± DIAGNOSTICSENGINE (5S±FE)
DI±73
308 Author: Date:
4 Check air induction system (See page SF±1).
NG Repair or replace.
OK
5 Check EGR system (See page EC±12).
NG Replace EGR system.
OK
6 Check fuel pressure (See page SF±6).
NG Check and repair fuel pump, fuel pipe line and
filter (See page SF±1).
OK
7 Check injector injection (See page SF±23).
NG Replace injector.
OK
Replace oxygen sensor
(bank 1 sensor 1).

DI±74
± DIAGNOSTICSENGINE (5S±FE)
309 Author: Date:
8 Perform confirmation driving pattern (See page DI±152).
Go
9 Is there DTC P0133 being output again?
NG Check for intermittent problems
(See page DI±3).
YES
Check and replace ECM (See page IN±31).

± DIAGNOSTICSENGINE (5S±FE)
DI±75
310 Author: Date:
DTC P0135 Heated Oxygen Sensor Heater Circuit Mal-
function (Bank 1 Sensor 1) (Ex. CA Spec.)
DTC P0141 Heated Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Except California Spec.)) on
page DI±55.
DTC No.DTC Detecting ConditionTrouble Area
P0135
P0141When heater operates, heater current exceeds 2 A
(2 trip detection logic)
Open or short in heater circuit of heated oxygen sensor
Htd htP0135
P0141Heater current of 0.2 A or less when heater operates
(2 trip detection logic)
Heated oxygen sensor heater

ECM
HINT:

Sensor 1 refers to the sensor closer to the engine body.

Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Except California Spec.)) on
page DI±55.
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.
DI00X±04

A03014A03415
ON
HT1
HT2
w/o Immobiliser
w/ Immobiliser
HT1
HT2
DI±76
± DIAGNOSTICSENGINE (5S±FE)
311 Author: Date:
1 Check voltage between terminals HT1, HT2 of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals HT1, HT2 of the ECM con-
nector and body ground.
HINT:

Connect terminal HT1 to bank 1 sensor 1.

Connect terminal HT2 to bank 1 sensor 2.
OK:
Voltage: 9 ~ 14 V
OK Check and replace ECM (See page IN±31).

NG
2 Check resistance of heated oxygen sensor heaters
(See pages SF±61, SF±63).
NG Replace heated oxygen sensor.
OK
Check and repair harness or connector between EFI main relay (Marking: EFI) and heated oxygen
sensor, and heated oxygen sensor and ECM. (See page IN±31).

± DIAGNOSTICSENGINE (5S±FE)
DI±77
312 Author: Date:
DTC P0136 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Except California Spec.)) on
page DI±55.
DTC No.DTC Detecting ConditionTrouble Area
P0136
Voltage output of heated oxygen sensor remains at
0.45*
1/0.40*2 V or more, or 0.60*1/0.50*2 V or less when ve-
hicle is driven at 40 km/h (25 mph) or more after engine is
warmed up
*
1: for California Spec.
*
2: except California Spec.
(2 trip detection logic).

Heated oxygen sensor
HINT:
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Except California Spec.)) on
page DI±55.
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 P0136) being output?
YES Go to relevant DTC chart.
NO
DI00Y±08

DI±78
± DIAGNOSTICSENGINE (5S±FE)
313 Author: Date:
2 Check for open and short in harness and connector between ECM and heated
oxygen sensor (See page IN±31).
NG Repair or replace harness or connector.
OK
3 Check output voltage of heated oxygen sensor.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand±held tester to the DLC3.
(b) Warm up the engine to normal operating temp.
CHECK:
Read voltage output of the heated oxygen sensor when the engine suddenly raced.
HINT:
Perform quick racing to 4,000 rpm 3 min. using the accelerator pedal.
OK:
Heated oxygen sensor output voltage:
Alternates from 0.45*
1/0.40*2 V or less to 0.60*1/0.50*2 V or more.
*1: for California Spec.
*
2: except California Spec.
OK Check that each connector is properly
connected.
NG
Replace heated oxygen sensor.

± DIAGNOSTICSENGINE (5S±FE)
DI±79
314 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 (loose hoses)

Fuel line pressure

Injector blockage

Manifold absolute pressure sensor

Engine coolant temp. sensor

A/F sensor
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

Manifold absolute pressure sensor

Engine coolant temp. sensor

A/F sensor
HINT:

When the DTC P0171 is recorded, the actual air±fuel ratio is on the lean side. When DTC P0172 is
recorded, the actual air±fuel ratio is on the rich side.

If the vehicle runs out of fuel, the air±fuel ratio is lean and DTC P0171 is recorded. The MIL then comes
on.

If the total of the short±term fuel trim value and long±term fuel trim value is within + 38 %, the system
is functioning normally.

The A/F sensor output voltage and the short±term fuel trim value can be read using the OBD II scan
tool or TOYOTA hand±held tester.

The ECM controls the voltage of AF
and AF terminals of ECM to the fixed voltage. Therefore, it
is impossible to confirm the A/F sensor output voltage without OBD II scan tool or TOYOTA hand±held
tester.
DI1JW±03

DI±80
± DIAGNOSTICSENGINE (5S±FE)
315 Author: Date:

OBD II scan tool (excluding TOYOTA hand±held tester) displays the one fifth of the A/F sensor output
voltage which is displayed on the TOYOTA hand±held tester.
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 airÅfuel ratio lean or rich, etc.
at the time of the malfunction.
1 Check air induction system (See page SF±1).
NG Repair or replace.
OK
2 Check injector injection (See page SF±23).
NG Replace injector.
OK
3 Check manifold absolute pressure sensor and engine coolant temp. sensor
(See pages SF±53 and SF±49).
NG Repair or replace.
OK
4 Check for spark and ignition (See page IG±1).
NG Repair or replace.
OK