2000 TOYOTA CAMRY check engine

± DIAGNOSTICSENGINE (1MZ±FE)
DI±265
500 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) on page DI±244.
DTC No.DTC Detecting ConditionTrouble Area
P0136
Voltage output of heated oxygen sensor (bank 1 sensor 2)
remains at 0.4 V or more or 0.6*1 0.5*2 V or less when vehicle
is driven at 50 km/h (31 mph) or more after engine is warmed
up
*
1: for California Spec.
*2: except California Spec.
(2 trip detection logic)

Heated oxygen sensor
HINT:
Bank 1 refers to the bank that includes cylinder No.1. 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) on page DI±244.
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
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
DI07Q±06

DI±266
± DIAGNOSTICSENGINE (1MZ±FE)
501 Author: Date:
3 Check output voltage of heated oxygen sensor (bank 1 sensor 2).
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 heated oxygen sensor (bank 1 sensor 2) when engine suddenly raced.
HINT:
Perform quick racing to 4,000 rpm 3 min. using accelerator pedal.
OK:
Heated oxygen sensor output voltage: Alternates from 0.4 V or less to 0.6*1/0.5*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
(bank 1 sensor 2).

DI±268
± DIAGNOSTICSENGINE (1MZ±FE)
503 Author: Date:
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 + 35 % (80°C (176°F)
or more), the system is functioning normally.

The A/F sensors (bank 1, 2 sensor 1) 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 AFR
, AFL
, AFR and AFL terminals of ECM to the fixed volt-
age. Therefore, it is impossible to confirm the A/F sensor output voltage without OBD II scan tool or
TOYOTA hand±held tester.

OBD II scan tool (excluding TOYOTA hand±held tester) displays the one fifth of the A/F sensors (bank
1, 2 sensor 1) output voltage which is displayed on the TOYOTA hand±held tester.
INSPECTION PROCEDURE
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 Check air induction system (See page SF±1).
NG Repair or replace.
OK
2 Check injector injection (See page SF±25).
NG Replace injector.
OK
3 Check mass air flow meter and engine coolant temp. sensor
(See pages SF±35 and SF±63).
NG Repair or replace.
OK

± 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

DI±270
± DIAGNOSTICSENGINE (1MZ±FE)
505 Author: Date:
7 Check the output voltage A/F sensors (bank1, 2 sensor1).
PREPARATION:
(a) Connect the OBDII scan tool or TOYOTA hand±held tester to the DLC3.
(b) Warm up the A/F sensors (bank1, 2 sensor1) with the engine at 2,500 rpm for approx. 90 sec.
CHECK:
Read voltage value of A/F sensors (bank1, 2 sensor1) on the screen of OBDII scan tool or TOYOTA hand±
held tester when you perform all the following conditions.
HINT:
The voltage of AFR
, AFL
terminal of ECM is 3.3 fixed AFR, AFL terminal is 3.0 V fixed. Therefore,
it is impossible to check the A/F sensors (bank1, 2 sensor1) output voltage at the terminals (AFR
, AFL
/
AFR, AFL) of ECM.
OK:
ConditionA/F Sensor Voltage value
Engine idling
Engine racing
Not remains at 3.30 V (*0.660 V)

Notremainsat38V(*076V)ormoreDriving at engine speed 1,500 rpm or more and vehicle
speed 40 km/h (25mph) or more, and operate throttle valve
open and close
Not remains at 3.8 V (*0.76 V) or more

Not remains at 2.8 V (*0.56 V) or less
*: When you use the OBDII scan tool (excluding TOYOTA hand±held tester)
HINT:

During fuel enrichment, there is a case that the output voltage of A/F sensors (bank1, 2 sensor1) is
below 2.8 V (*0.56 V), it is normal.

During fuel cut, there is case that the output voltage of A/F sensors (bank1, 2 sensor1) is above 3.8
V (*0.76 V), it is normal.

If output voltage of A/F sensors (bank1, 2 sensor1) remains at 3.30 V (*0.660 V) even after performing
all the above conditions, A/F sensors (bank1, 2 sensor1) circuit may be open.

If output voltage of A/F sensors (bank1, 2 sensor1) remains at 3.8 V (*0.76 V) or more, or 2.8 V (*0.56
V) or less even after performing all the above conditions, A/F sensors (bank1, 2 sensor1) circuit may
be short.
*: When you use the OBDII scan tool (excluding TOYOTA hand±held tester).
OK Go to step 9.
NG

± DIAGNOSTICSENGINE (1MZ±FE)
DI±271
506 Author: Date:
8 Check for open and short in harness and connector between ECM and A/F sen-
sors (bank1, 2 sensor1) (See page IN±31).
NG Repair or replace harness or connector.
OK
Replace A/F sensors (bank1, 2 sensor1).
9 perform confirmation driving pattern (See page DI±340).
Go
10 Is there DTC P0171 or P0172 being output again ?
YES Check and replace ECM
(See page IN±31).
NO
11 Did vehicle runs out of fuel in the past ?
NO Check for intermittent problems
(See page DI±197).
YES
DTC P0171 or P0172 is caused by running out of fuel.

± DIAGNOSTICSENGINE (1MZ±FE)
DI±273
508 Author: Date:
1 Check air induction system (See page SF±1).
NG Repair or replace.
OK
2 Check injector injection (See page SF±21).
NG Replace injector.
OK
3 Check mass air flow meter and engine coolant temp. sensor
(See pages SF±35 and SF±63).
NG Repair or replace.
OK
4 Check for spark and ignition (See page IG±1).
NG Repair or replace.
OK
5 Check fuel pressure (See page SF±6).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter.
OK

P18349
DI±274
± DIAGNOSTICSENGINE (1MZ±FE)
509 Author: Date:
6 Check gas leakage on exhaust system.
NG Repair or replace.
OK
7 Check the output voltage of heated oxygen sensors (bank1, 2 sensor1) during
idling.
PREPARATION:
Warm up the heated oxygen sensors (bank1, 2 sensor1) the engine at 2,500 rpm for approx. 90 sec.
CHECK:
Use the OBDII scan tool or TOYOTA hand±held tester to read the output voltage of the heated oxygen sen-
sors (bank1, 2 sensor1) during idling.
OK:
Heated oxygen sensors (bank1, 2 sensor1) output voltage:
Alternates repeatedly between less than 0.4 V and more than 0.55 V (See the Following table).
OK Go to step 9.
NG