Lexus ES300 (2002 year). Service manual — part 383

05-138

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

291

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

DTC

P1133

A/F SENSOR CIRCUIT RESPONSE
MALFUNCTION(BANK1 SENSOR1)

DTC

P1153

A/F SENSOR CIRCUIT RESPONSE
MALFUNCTION(BANK2 SENSOR1)

CIRCUIT DESCRIPTION

Refer to DTC P0125 on page

05-52

.

DTC No.

DTC Detecting Condition

Trouble Area

P1133
P1153

After engine is warmed up, and during vehicle driving at engine
speed 1,400 rpm or more and vehicle speed 60 km/h (38 mph)
or more, if the response characteristic of A/F sensor becomes
deteriorated (2 trip detection logic)

Open or short in A/F sensor circuit

A/F sensor

Air induction system

Fuel pressure

Injector

ECM

WIRING DIAGRAM

Refer to DTC P0125 on page

05-52

.

INSPECTION PROCEDURE

HINT:
Read freeze frame data using hand-held tester or OBD II scan tool. Because freeze frame records the en-
gine conditions when the malfunction is detected. When troubleshooting, it is useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich,
etc. at the time of the malfunction.

1

CHECK OTHER DTC OUTPUT(BESIDES DTC P1133, P1153)

(a)

Read the DTC using the hand-held tester or OBD II scan tool.

YES

GO TO RELEVANT DTC CHART

NO

051MH-08

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-139

292

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

2

READ VALUE OF OBD II SCAN TOOL OR HAND-HELD TESTER(AIR FUEL RATIO
SENSOR)

(a)

Warm up the A/F sensor with the engine speed at 2,500 rpm for approx. 90 sec.

(b)

Read the voltage of the A/F sensor on the screen of the OBD II scan tool or hand-held tester when
you perform all the following conditions.

HINT:
The voltage of the AFR+ or AFL+ terminal of the ECM is fixed at 3.3 V and the voltage of the AFR- or AFL-
terminal is fixed at 3.0 V. Therefore, it is impossible to check the A/F sensor output voltage at the terminals
(AFR+, AFL+/AFR-, AFL-) of the ECM.

Result:

Condition

A/F Sensor Voltage value

Engine idling

Not remains at 3 30 V (0 660 V*)

Engine racing

Not remains at 3.30 V (0.660 V*)

Not remains at 3 8 V (0 76 V*) or more

Driving at engine speed 1,500 rpm or more and vehicle
speed 40 km/h (25 mph) 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 OBD II scan tool (excluding hand-held tester)

HINT:

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

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

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

If the output voltage of the A/F sensor remains at 3.8 V (0.76V*) or more, or 2.8 V (0.56 V*) or less even
after performing all the above conditions, the A/F sensor circuit may be short.

*: When you use the OBD II scan tool (excluding hand-held tester).

OK

Go to step 8

NG

3

CHECK HARNESS AND CONNECTOR(ECM - A/F SENSOR)

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

OK

4

CHECK AIR FUEL RATIO SENSOR(RESISTANCE) (See page

12-6

)

NG

REPLACE AIR FUEL RATIO SENSOR

OK

5

CHECK AIR INDUCTION SYSTEM (See page

11-1

)

NG

REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK

05-140

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DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

293

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

6

CHECK FUEL PRESSURE (See page

11-1

)

NG

REPAIR OR REPLACE FUEL SYSTEM

OK

7

INSPECT FUEL INJECTOR ASSY (See page

11-7

)

NG

REPLACE FUEL INJECTOR ASSY

OK

REPLACE AIR FUEL RATIO SENSOR

8

PERFORM CONFIRMATION DRIVING PATTERN (See page

05-52

)

GO

9

READ OUTPUT DTC(DTC P1133 OR P1153 OUTPUT AGAIN)

YES

CHECK AND REPLACE ECM

NO

10

CONFIRM VEHICLE RUNS OUT OF FUEL IN THE PAST

NO

CHECK FOR INTERMITTENT PROBLEMS

YES

DTC P1133 OR P1153 IS CAUSED BY RUNNING OUT OF FUEL

A53763

HAFR

HAFL

E2

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-141

294

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

DTC

P1135

A/F SENSOR HEATER CIRCUIT
MALFUNCTION(BANK1 SENSOR1)

DTC

P1155

A/F SENSOR HEATER CIRCUIT
MALFUNCTION(BANK2 SENSOR1)

CIRCUIT DESCRIPTION

Refer to DTC P0125 on page

05-52

.

DTC No.

DTC Detecting Condition

Trouble Area

P1135

When the heater operates, heater current exceeds 8 A
(2 trip detection logic)

Open or short in heater circuit of A/F sensor

A/F sensor heater

P1135
P1155

Heater current of 0.25 A or less when the heater operates
(2 trip detection logic)

A/F sensor heater

A/F HTR relay

ECM

WIRING DIAGRAM

Refer to DTC P0125 on page

05-52

.

INSPECTION PROCEDURE

HINT:
Read freeze frame data using hand-held tester or OBD II scan tool. Because freeze frame records the en-
gine conditions when the malfunction is detected. When troubleshooting, it is useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich,
etc. at the time of the malfunction.

1

INSPECT ECM

(a)

Turn the ignition switch ON.

(b)

Measure the voltage between terminals HAFL, HAFR and
E2 of the ECM connector.
Voltage: 9 - 14 V

OK

CHECK AND REPLACE ECM

NG

2

CHECK AIR FUEL RATIO SENSOR(RESISTANCE) (See page

12-6

)

NG

REPLACE AIR FUEL RATIO SENSOR

OK

051MI-08