Lexus ES300 (2002 year). Service manual - part 382

05-134

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

287

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

P1130

A/F SENSOR CIRCUIT
RANGE/PERFORMANCE
MALFUNCTION(BANK1 SENSOR1)

DTC

P1150

A/F SENSOR CIRCUIT
RANGE/PERFORMANCE
MALFUNCTION(BANK2 SENSOR1)

CIRCUIT DESCRIPTION

Refer to DTC P0125 on page 

05-52

.

DTC No.

DTC Detecting Condition

Trouble Area

P1130

Voltage output* of A/F sensor remains at 3.8 V or more, or 2.8
V or less, during engine running after the engine is warmed up
(2 trip detection logic)
*: Output value changes at inside of ECM only



Open or short in A/F sensor circuit



A/F sensor
Ai i d

ti

t

P1130
P1150

Voltage output* of A/F sensor does not change from 3.30 V,
during engine running after the engine is warmed up (2 trip
detection logic)
*: Output value changes at the inside of ECM only



Air induction system



Fuel pressure



Injector



ECM

Open or short in A/F sensor circuit (2 trip detection logic)

HINT:



After confirming DTC P1130, use the OBD II scan tool 

or

 hand−held tester to confirm voltage output

of A/F sensor 

(AFS B1 S1/O2S B1 S1) 

from the CURRENT DATA.



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



The ECM controls the voltage of the AFR+, AFL+, AFR− and AFL− 

terminals of the ECM to the fixed

voltage. Therefore, it is impossible to confirm the A/F sensor output voltage without the OBDII scan
tool or hand-held tester.



OBD II scan tool (excluding hand−held tester) displays the one fifth of the A/F sensor output voltage
which is displayed on the hand−held tester.

WIRING DIAGRAM

Refer to DTC P0125 on page 

05-52

.

051MG-11

Vehicle Speed

60 - 120 km/h

(38 - 75 mph)

Idling

IG SW OFF

3 - 5 min.

Time

(

1)

(

2)

(

3)

A53001

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DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-135

288

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

CONFIRMATION DRIVING PATTERN

1.

Connect the hand-held tester to the DLC3. (

1)

2.

Switch the hand-held tester from the normal mode to the check mode 
(See page 

05-5

).(

1)

3.

Start the engine and warm it up with all the accessory switches OFF.(

2)

4.

Drive the vehicle at 60 - 120 km/h (38 -

 

75 mph) and engine speed at 1,400 - 3,200 rpm for 3

 

-

5 min.(

3)

HINT:
If a malfunction exists, the MIL will light up during step (

3)

NOTICE:
If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a hand-held tester, turn the ignition switch OFF after performing steps (

2) and

(

3), then perform steps (

2) and (

3) again.

INSPECTION PROCEDURE

HINT:



If DTC P1130 is displayed, check Bank 1 Sensor 1 circuit.



If DTC P1150 is displayed, check Bank 2 Sensor 1 circuit.



Read freeze frame data using 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 deter-
mining 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 P1130, P1150)

(a)

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

YES

GO TO RELEVANT DTC CHART

NO

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DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

289

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

2

CHECK AIR FUEL RATIO SENSOR(OUTPUT VOLTAGE)

(a)

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

(b)

Read the voltage value of the A/F sensor on the screen of OBDII 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 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 normally.



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 (0.76 V*) 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

OK

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DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-137

290

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 P1130 OR P1150 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 P1130 OR P1150 IS CAUSED BY RUNNING OUT OF FUEL