Lexus RX300 (MCU15). Service manual — part 195

DI–12

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DIAGNOSTICS

ENGINE

LEXUS RX300 (RM785E)

7.

ENGINE OPERATING CONDITION

NOTICE:
The values given below for ”Normal Condition” are representative values, so a vehicle may still be
normal even if its value from those listed here. So do not decide whether a part is faulty or not solely
according to the ”Normal Condition” here.

Hand–held tester display

Measurement Item

Normal Condition*

FUEL SYS #1

Fuel System Bank 1

OPEN: Air–fuel ratio feedback stopped

CLOSED: Air–fuel ratio feedback operating

Idling after warming up: CLOSED

FUEL SYS #2

Fuel System Bank 2

OPEN: Air–fuel ratio feedback stopped

CLOSED: Air–fuel ratio feedback operating

Idling after warming up: CLOSED

CALC LOAD

Calculator Load: Current intake air volume as a

proportion of max. intake air volume

Idling: 13.1 – 18.7 %

Racing without load (2,500rpm): 11.7 – 17.3 %

COOLANT TEMP

Engine Coolant Temp. Sensor Value

After warming up: 80 – 95°C (176 – 203°F)

SHORT FT #1

Short–term Fuel Trim Bank 1

0

± 20%

LONG FT #1

Long–term Fuel Trim Bank 1

0

± 20%

SHORT FT #2

Short–term Fuel Trim Bank 2

0

± 20%

LONG FT #2

Long–term Fuel Trim Bank 2

0

± 20 %

ENGINE SPD

Engine Speed

Idling: 650 –

750 rpm

VEHICLE SPD

Vehicle Speed

Vehicle stopped: 0 km/h (0 mph)

IGN ADVANCE

Ignition Advance: Ignition Timing of Cylinder No.1

Idling: BTDC 8 – 12°

INTAKE AIR

Intake Air Temp. Sensor Value

Equivalent to Ambient Temp.

MAF

Air Flow Rate Through Mass Air Flow Meter

Idling: 3.3 – 4.7 gm/sec.

Racing without load (2,500 rpm):

10.4 – 15.4 gm/sec.

THROTTLE POS

Voltage Output of Throttle Position Sensor Calcu-

lated as a percentage: 0 V → 0 %, 5 V → 100 %

Throttle valve fully closed: 7 – 11 %

Throttle valve fully open: 65 – 75 %

O2S B1 S2

Voltage Output of Oxygen Sensor Bank 1, Sen-

sor 2

Driving 50 km/h (31 mph): 0.05 – 0.95 V

A/FS B1 S1

Voltage Output of A/F Sensor Bank 1 Sensor 1

Idling: 2.8 – 3.8 V

A/FS B2 S1

Voltage Output of A/F Sensor Bank 2 Sensor 1

Idling: 2.8 – 3.8 V

A/FFT B1 S1

A/F Sensor Fuel Trim Bank 1, Sensor 1

(Same as SHORT FT #1)

0 ± 20 %

A/FFT B2 S1

A/F Sensor Fuel Trim Bank 2, Sensor 1

(Same as SHORT FT #1)

0 ± 20 %

MISFIRE RPM

Engine RPM for first misfire range

Misfire 0: 0 rpm

MISFIRE LOAD

Engine load for first misfire range

Misfire 0: 0 g/r

INJECTOR

Fuel injection time for cylinder No.1

Idling: 1.6 – 2.9 ms

MIL ON RUN DIST

Distance since activation of check engine warn-

ing light

When there is no DTC: 0 km (0 mile)

IAC DUTY RATIO

Intake Air Control Valve Duty Ratio

Opening ratio rotary solenoid type IAC valve

Idling: 27 – 47 %

STARTER SIG

Starter Signal

Cranking: ON

CTP SIG

Closed Throttle Position Signal

Throttle fully closed: ON

A/C SIG

A/C Switch Signal

A/C ON: ON

PNP SW

Park/Neutral Position Switch Signal

P or N position: ON

ELCTRCL LOAD SIG

Electrical Load Signal

Defogger switch ON: ON

STOP LIGHT SW

Stop Light Switch Signal

Stop light switch ON: ON

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DIAGNOSTICS

ENGINE

DI–13

LEXUS RX300 (RM785E)

PS OIL PRESS SW

Power Steering Oil Pressure Switch Signal

Turn steering wheel: ON

FC IDL

Fuel Cut Idle: Fuel cut when throttle valve fully

closed, during deceleration

Fuel cut operating: ON

FC TAU

Fuel Cut TAU: Fuel cut during very light load

Fuel cut operating: ON

CYL#1 – CYL#6

Abnormal revolution variation for each cylinder

0 %

IGNITION

Total number of ignition for every 1,000 revolu-

tions

0 – 3,000

INTAKE CTRL VSV

Intake Air Control Valve VSV Signal

VSV operating: ON

A/C CUT SIG

A/C Cut Signal

A/C S/W OFF: ON

FUEL PUMP

Fuel Pump Signal

Idling: ON

EVAP (PURGE) VSV

EVAP VSV Signal

VSV operating: Above 30 %

VAPOR PRESS VSV

Vapor Pressure VSV Signal

VSV operating: ON

TOTAL FT B1

Total Fuel Trim Bank 1: Average value for fuel

trim system of bank 1

Idling: 0.8 – 1.2

TOTAL FT B2

Total Fuel Trim Bank 1: Average value for fuel

trim system of bank 2

Idling: 0.8 – 1.2

*

: If no conditions are specifically stated for ”ldling”, it means the shift lever is at P position, the A/C switch

is OFF and all accessory switches are OFF.

DI12C–22

DI–14

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DIAGNOSTICS

ENGINE

LEXUS RX300 (RM785E)

DIAGNOSTIC TROUBLE CODE CHART

SAE CONTROLLED
HINT:
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 that code 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.

DTC No.

(See Page)

Detection Item

Trouble Area

CHK

ENG*

1

Memory

P0100

(DI–22)

Mass Air Flow Circuit Malfunc-

tion

S Open or short in air flow meter circuit

S Air flow meter

S Engine ECU

f

f

P0101

(DI–26)

Mass Air Flow Circuit Range/

Performance Problem

S Air flow meter

f

f

P0110

(DI–26)

Intake Air Temp. Circuit

Malfunction

S Open or short in intake air temp. sensor circuit

S Intake air temp. sensor (built into air flow meter)

S Engine ECU

f

f

P0115

(DI–31)

Engine Coolant Temp. Circuit

Malfunction

S Open or short in water temp. sensor circuit

S Water temp. sensor

S Engine ECU

f

f

P0116

(DI–35)

Engine Coolant Temp. Circuit

Range/Performance Probrem

S Engine coolant temp. sensor

S Cooling system

f

f

P0120

(DI–36)

Throttle/Pedal Position Sensor/

Switch ”A” Circuit Malfunction

S Open or short in throttle position sensor circuit

S Throttle position sensor

S Engine ECU

f

f

P0121

(DI–41)

Throttle/Pedal Position Sensor/

Switch ”A” Circuit Range/Perfor-

mance Problem

S Throttle position sensor

f

f

P0125

(DI–42)

Insufficient Coolant Temp. for

Closed Loop Fuel Control

S Air induction system

S Fuel pressure

S Injector injection

S Gas leakage on exhaust system

S Open or short in heated oxygen sensor (bank 1 sensor 1)

circuit

S Oxygen sensor (bank 1 sensor 1)

f

f

P0136

*2

(DI–48)

Oxygen Sensor Circuit Malfunc-

tion (Bank 1 Sensor 2)

S Open or short in heater circuit of oxygen sensor

S Oxygen sensor

f

f

P0141

(DI–50)

Oxygen Sensor Heater Circuit

Malfunction (Bank 1 Sensor 2)

S Same as DTC No. P0135

f

f

P0171

*2

(DI–52)

Fuel Trim System too Lean

(A/F Lean Malfunction, Bank 1)

S Air intake (hose loose)

S Fuel line pressure

S Injector blockage

S Oxygen sensor malfunction

S Air flow meter

S Water temp. sensor

f

f

P0172

*2

(DI–52)

System too Rich

(A/F Rich Malfunction Bank 1)

S Fuel line pressure

S Injector leak, blockage

S Heated oxygen sensor malfunction

S Mass air flow meter

S Engine coolant temp. sensor

S Gas leakage on exhaust system

f

f

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DIAGNOSTICS

ENGINE

DI–15

LEXUS RX300 (RM785E)

P0174

*2

(DI–52)

System too Lean

(A/F Lean Malfunction Bank 2)

Same as DTC No. P0171

f

f

P0175

*2

(DI–52)

System too Rich

(A/F Rich Malfunction Bank 2)

Same as DTC No. P0172

f

f

P0300

*2

(DI–57)

Random/Multiple Cylinder

Misfire Detected

P0301

*2

(DI–57)

Cylinder 1 Misfire Detected

S Ignition system

S Injector

P0302

*2

(DI–57)

Cylinder 2 Misfire Detected

Injector

S Fuel pressure

S Compression pressure

P0303

*2

(DI–57)

Cylinder 3 Misfire Detected

S Valve clearance

S Valve timing

S Air flow meter

f

f

P0304

*2

(DI–57)

Cylinder 4 Misfire Detected

S Air flow meter

S Water temp. sensor

S Open or short in engine wire

P0305

*2

(DI–57)

Cylinder 5 Misfire Detected

O en or short in engine wire

S Connector connection

S Engine ECU

P0306

*2

(DI–57)

Cylinder 6 Misfire Detected

P0325

(DI–63)

Knock Sensor 1 Circuit

Malfunction

S Open or short in knock sensor 1 circuit

S Knock sensor 1 (looseness)

S Engine ECU

f

f

P0330

(DI–63)

Knock Sensor 2 Circuit

Malfunction (Bank 2)

S Open or short in knock sensor 2 circuit

S Knock sensor 2 (looseness)

S Engine ECU

f

f

P0335

(DI–67)

Crankshaft Position Sensor

”A” Circuit Malfunction

S Open or short in crankshaft position sensor circuit

S Crankshaft position sensor

S Signal plate

S Engine ECU

f

f

P0340

(DI–69)

Camshaft Position Sensor

Circuit Malfunction

S Open or short in camshaft position sensor circuit

S Camshaft position sensor

S Engine ECU

f

f

P0420

*2

(DI–71)

Catalyst System Efficiency

Below Threshould (Bank 1)

S Gas leakage on exhaust system

S Oxygen sensor

S Three–way catalytic converter

f

f

P0443

(DI–74)

Evaporative Emission Control

System Purge Control Vent

Control Malfunction

S Open or short in VSV circuit for EVAP

S VSV for EVAP

S Engine ECU

f

f

P0500

(DI–77)

Vehicle Speed Sensor

Malfunction

S Combination meter

S Open or short in No.1 vehicle speed sensor circuit

S Engine ECU

S No.1 vehicle speed sensor

f

f

P0505

(DI–80)

Idle Control System

Malfunction

S Open or short in ISC valve circuit

S ISC valve is stuck or closed

S Open or short in A/C signal circuit

S Air induction system

S Engine ECU

f

f

P1130

*2

(DI–85)

A/F Sensor Circuit Range/Perfor-

mance Malfunction (Bank 1 Sen-

sor 1)

S Open or short in A/F sensor circuit

S A/F sensor

S Air induction system

S Fuel pressure

S Injector

S Engine ECM

f

f