Lexus ES300 (2002 year). Manual - part 385

A53763

IGF

E2

A54406

E10

IGT1

E2

+B

IGF IGT GND

A50294

05-146

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

299

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

3

INSPECT ECM

(a)

Disconnect the ignition coil connector.

(b)

Turn the ignition switch ON

(c)

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

OK

CHECK AND REPLACE ECM

NG

CHECK AND REPLACE ECM

4

CHECK HARNESS AND CONNECTOR(ECM - IGNITION COIL)

HINT:
The procedure below is for No.1 cylinder. If a malfunction is
found on the other cylinders, check the circuit for the cylinder
with referring to this procedure.
(a)

Disconnect the ignition coil connector.

(b)

Disconnect the ECM E10 connector.

(c)

Check for open between the terminals IGT1 of the ECM
connector and IGT of the ignition coil connector.
Resistance: 1 

Ω

 or less

(d)

Check for short between the terminals IGT1 and E2 of the
ECM connector.
Resistance: 1 M

Ω

 or less

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

OK

A53763

IGT1

E2

IGT2

IGT3

IGT4

IGT5

IGT6

A31764

A53763

IGT1

E2

IGT2

IGT3

IGT4

IGT5

IGT6

+B

IGF IGT GND

A50294

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-147

300

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

5

INSPECT ECM

(a)

Turn the ignition switch ON.

(b)

Measure the voltage between terminals IGT1 - IGT6 and
E2 of the ECM connector when the engine is cranked.
Voltage: More than 0.1 V and less than 4.5 V

HINT:
During cranking or idling, check the waveform between termi-
nals IGT1 - IGT6 and E2 of the ECM connector.

Item

Contents

Terminal

CH1: IGT1, IGT2, IGT3, IGT4, IGT5, IGT6 - E2
CH2: IGF - E2

Equipment Set

2V/DIV, 20ms/DIV

Condition

While the engine is cranking or idling

HINT:
Correct waveform appears as shown, with rectangle waves.

NG

CHECK AND REPLACE ECM

OK

6

INSPECT ECM

(a)

Disconnect the ignition coil with the igniter connector.

(b)

Turn the ignition switch ON.

(c)

Measure the voltage between terminals IGT1 - IGT6 and
E2 of the ECM connector when the engine is cranked.
Voltage: More than 0.1 V and less than 4.5 V

NG

CHECK AND REPLACE ECM

OK

7

CHECK IGNITION COIL ASSY(POWER SOUSE CIRCUIT)

(a)

Disconnect the ignition coil with the igniter connector.

(b)

Turn the ignition switch ON.

(c)

Measure voltage between terminals+B and GND of the
ignition coil with the igniter connector.
Voltage: 9 - 14 V

+B

IGF IGT GND

A50294

1

5

6

2

3

7

8

4

A56879

IG2

05-148

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

301

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

NG

REPAIR OR REPLACE POWER SOURCE

OK

8

CHECK HARNESS AND CONNECTOR(IGUNITION SWITCH - IGNITION COIL)

(a)

Disconnect the ignition coil with the igniter connector.

(b)

Disconnect the ignition switch connector.

(c)

Check open between the terminals +B of the ignitioncoil
with igniter connector and IG2 of the ignition switch.
Resistance: 1 

Ω

 or less

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

OK

REPLACE IGNITION COIL ASSY

051MZ-08

05-18

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

171

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DIAGNOSTIC TROUBLE CODE CHART

Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument
or other factors.
If a malfunction code is displayed during the DTC check in check mode, check the circuit for the codes listed
in the table below. For details of each code, turn to the page referred to under the ’’See page ’’ for the respec-
tive ’’DTC No.’’ in the DTC chart.
SAE CONTROLLED

DTC No.

(See Page)

Detection Item

Trouble Area

MIL

*1

Memory

P0100

(

05-31

)

Mass Air Flow Circuit Malfunc-
tion

Open or short in intake air flow meter circuit

Intake air flow meter

ECM





P0101

(

05-37

)

Mass Air Flow Circuit Range/
Performance Problem

Intake air flow meter





P0110

(

05-38

)

Intake Air Temp. Circuit Malfunc-
tion

Open or short in intake air temp. sensor circuit

Intake air temp. sensor (inside intake air flow meter)

ECM





P0115

(

05-41

)

Engine Coolant Temp. Circuit
Malfunction

Open or short in E.F.I. engine coolant temp. sensor circuit

E.F.I. engine coolant temp. sensor

ECM





P0116

(

05-44

)

Engine Coolant Temp. Circuit
Range/Performance Problem

Cooling system

E.F.I. engine coolant temp. sensor





P0120

(

05-45

)

Throttle/Pedal Position Sensor/
Switch ”A” Circuit Malfunction

Open or short in throttle position sensor circuit

Throttle position sensor

ECM





P0121

(

05-51

)

Throttle/Pedal Position Sensor/
Switch ”A” Circuit Range/Perfor-
mance Problem

Throttle body assy (Throttle position sensor)

ECM





P0125

(

05-52

)

Insufficient Coolant Temp. for
Closed Loop Fuel Control

Open or short in A/F sensor (bank 1, 2 sensor 1) circuit

A/F sensor (bank 1, 2 sensor 1)

Air induction system

Fuel pressure

Injector

Gas leakage on exhaust system

PCV hose connection

ECM





P0128

(

05-58

)

Thermostat Malfunction

Thermostat

Cooling system

E.F.I. engine coolant temp. sensor

ECM





P0136

(

05-59

)

Heated Oxygen Sensor Circuit
Malfunction (Bank 1 Sensor 2)

Open or short in heated oxygen sensor circuit

Oxygen sensor





P0141

(

05-63

)

Heated Oxygen Sensor Circuit
Malfunction (Bank 1 Sensor 2)

Open or short in heater circuit of heated oxygen sensor

Oxygen sensor heater

ECM





P0156

(

05-59

)

Heated Oxygen Sensor Circuit
Malfunction (Bank 2 Sensor 2)

Same as DTC No. P0136





P0161

(

05-63

)

Heated Oxygen Sensor Circuit
Malfunction (Bank 2 Sensor 2)

Same as DTC No. P0141