Lexus ES300 (2002 year). Manual - part 357

A61997

VC VTA1 VTA2 E2

A54406

E10

A53763

E2

VC

05-48

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

201

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

5

CHECK HARNESS AND CONNECTOR(ECM - THROTTLE BODY)

(a)

Disconnect the throttle position sensor connector and
ECM E10 connector. Read throttle opening angle on the
hand-held  tester.
Throttle opening percentage:
Accelerator pedal released: 0 %
Accelerator pedal depressed: 64 - 96 %

HINT:
If the throttle position is 100 % when releasing throttle pedal, E2
circuit is open.
If the throttle position is 0 % when depressing accelerator ped-
al, VC or VTA1 circuit is open.
If  the throttle position is not  0 % when releasing accelerator
pedal or throttle position is not 100 % when depressing throttle
pedal, VTA2 circuit is open or short.

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

OK

CHECK AND REPLACE ECM

OBD II scan tool (excluding Hand-held Tester):

1

INSPECT ECM(VC - E2)

(a)

Measure the voltage between terminals VC and E2 of the
ECM connector.
Voltage: 4.5 - 5.5 V

NG

CHECK AND REPLACE ECM

OK

A53763

VTA1

VTA2

E2

A54410

E2

VC

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-49

202

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

2

INSPECT ECM(VTA1 - E2, VTA2 - E2)

(a)

Measure the voltage between terminals VTA1 and E2,
and VTA2 and E2 of the ECM connector.

A

l

t

d l

Voltage

Accelerator pedal

VTA1 - E

VTA2 - E2

Released

0.4 - 1.0 V

2.0 - 2.9 V

Depressed

3.2 - 4.8 V

4.6 - 5.0 V

OK

CHECK AND REPLACE ECM

NG

3

INSPECT E.F.I. THROTTLE POSITION SENSOR

(a)

Disconnect the throttle position sensor connector.

(b)

Using an ohmmeter, measure the resistance between ter-
minals VC and E2.
Resistance: 1.2 - 3.2 k

Ω

 at 20

°

C (68

°

F)

NG

REPLACE E.F.I. THROTTLE POSITION SENSOR

OK

A61997

VC VTA1 VTA2 E2

A54406

E10

05-50

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

203

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

4

CHECK HARNESS AND CONNECTOR(ECM - THROTTLE BODY)

(a)

Disconnect the throttle position sensor connector and
E10 connector. Read throttle opening angle on the OBD
ll scan tool.
Throttle opening percentage:
Accelerator pedal released: 0 %
Accelerator pedal depressed: 64 - 96 %

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

OK

CHECK AND REPLACE ECM

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-51

204

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

P0121

THROTTLE/PEDAL POSITION
SENSOR/SWITCH”A”CIRCUIT
RANGE/PERFFORMANCE PROBLEM

CIRCUIT DESCRIPTION

Refer to DTC P0120 on page 

05-45

.

DTC No.

DTC Detecting Condition

Trouble Area

P0121

Condition (a) continues for 2.0 seconds: (IDL ON: 10 seconds)
(a) Difference between VTA1 and VTA2 is out of thresshold 
(b) IDL is OFF

Throttle position sensor

ECM

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.

REPLACE E.F.I. THROTTLE POSITION SENSOR

051M0-07