check engine LEXUS LS430 2003 Factory Owner's Manual

1.PERFORM ACTIVE TEST BY HAND-HELD TESTER (TRAC OFF INDICATOR LIGHT)
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the item "TRAC OFF LIGHT" in the ACTIVE TEST and operate the TRAC OFF indicator
light on the hand-held tester.
VEHICLE CONDITION / TEST DETAILS
d. Check that "ON" and "OFF" of the TRAC OFF indicator light are indicated on the combination
meter when using the hand-held tester.
OK: Go to next step
Turn the TRAC OFF indicator light on or off in accordance with the hand-held tester.
NG: Go to step 5
OK: Go to next step
2.INSPECT MULTIPLEX COMMUNICATION SYSTEM
a. Is the DTC output for Multiplex communication system?
Result:
DTC OUTPUT DESCRIPTION
B: REPAIR MULTIPLEX COMMUNICATION SYSTEM (SEE DIAGNOSTIC TROUBLE
CODE CHART )
A: Go to next step
3.INSPECT CAN COMMUNICATION SYSTEM
a. Is the DTC output for CAN communication system?
Result:
DTC OUTPUT DESCRIPTION
ItemVehicle Condition / Test DetailsDiagnostic Note
VSC / TRAC OFF INDTurns VSC / TRAC OFF indicator ON / OFFObserve combination meter
DTC is not outputA
DTC is outputB
DTC is not outputA
DTC is outputB

a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the item "SLIP INDI LIGHT" in the ACTIVE TEST and operate the SLIP indicator light on
the hand-held tester.
VEHICLE CONDITION / TEST DETAILS
d. Check that "ON" and "OFF" of the SLIP indicator light are indicated on the combination meter
when using the hand-held tester.
OK: Go to next step
Turn the SLIP indicator light on or off in accordance with the hand-held tester.
NG: Go to step 2
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
2.INSPECT MULTIPLEX COMMUNICATION SYSTEM
a. Is the DTC output for Multiplex communication system?
Result:
DTC OUTPUT DESCRIPTION
B: REPAIR MULTIPLEX COMMUNICATION SYSTEM (SEE DIAGNOSTIC TROUBLE
CODE CHART )
A: Go to next step
3.INSPECT CAN COMMUNICATION SYSTEM
a. Is the DTC output for CAN communication system?
Result:
DTC OUTPUT DESCRIPTION
ItemVehicle Condition / Test DetailsDiagnostic Note
SLIP INDI LIGHTTurns SLIP indicator light ON / OFFObserve combination meter
DTC is not outputA
DTC is outputB
DTC is not outputA

Fig. 76: Pressure Switch Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK REFRIGERANT VOLUME
a. Check the sight glass on the liquid tube.
Test conditions:
Engine is running at 1,500 rpm
Single A/C:
Blower speed control switch at "HI" position
Dual A/C:
Front blower switch at "HI" position
Rear blower switch at "HI" position

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT AIR CONDITIONING AMPLIFIER (SOL+ - SOL-)
a. Remove the A/C amplifier with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (SOL+ - SOL-) VOLTAGE
HINT:
As the temperature increases, the voltage decreases.
Result:
AIR CONDITIONING AMPLIFIER (SOL+ - SOL-) TEST RESULT
Tester connectionConditionSpecified condition
A11-6 (SOL+) - A11-7 (SOL-)Start the engine Auto switch: ONBelow 1.0 V
ANG
BOK (Checking from the PROBLEM SYMPTOMS TABLE)
COK (Checking from the DTC)

1.PERFORM ACTUATOR CHECK
a. Warm up the engine.
b. Set the actuator check mode (SEE ACTUATOR CHECK
).
c. Press the driver temperature up switch, and change to STEP operation.
d. Press the driver temperature up switch, and check the air flow by hand.
DISPLAY CODE - AIR FLOW POSITION
OK:
Cool air bypass damper changes in accordance with each display code.
NG: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
OK: Go to next step
2.INSPECT COOL AIR BYPASS SERVOMOTOR
a. Remove the cool air bypass servomotor.
b. Connect the positive (+) lead from the battery to terminal 4 and negative (-) lead to terminal 5, then
check that the lever turns to the "OPEN" position smoothly.
c. Connect the positive (+) lead from the battery to terminal 5 and negative (-) lead to terminal 4, then
check that the lever turns to the "SHUT" position smoothl
y.
Display codeAir flow position
0OPEN
1OPEN
2OPEN
3SHUT
4SHUT
5SHUT
6SHUT
7SHUT
8SHUT
9SHUT

Fig. 129: Cool Air Bypass Damper Control Servomotor Circuit (Passenger Side)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.PERFORM ACTUATOR CHECK

a. Warm up the engine.
b. Set the actuator check mode (SEE ACTUATOR CHECK
).
c. Press the driver temperature up switch, and change to STEP operation.
d. Press the driver temperature up switch, and check the air flow by hand.
Display code Air flow position
DISPLAY CODE AIR FLOW POSITION
OK:
Cool air bypass damper changes in accordance with each display code.
NG: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
OK: Go to next step
2.INSPECT COOL AIR BYPASS SERVOMOTOR
a. Remove the cool air bypass servomotor.
b. Connect the positive (+) lead from the battery to terminal 4 and negative (-) lead to terminal 5, then
check that the lever turns to the "OPEN" position smoothly.
c. Connect the positive (+) lead from the battery to terminal 5 and negative (-) lead to terminal 4, then
check that the lever turns to the "SHUT" position smoothly.
Display codeAir flow lever position
0OPEN
1OPEN
2OPEN
3SHUT
4SHUT
5SHUT
6SHUT
7SHUT
8SHUT
9SHUT

INSPECTION PROCEDURE
1.PERFORM ACTUATOR CHECK

a. Warm up the engine.
b. Set the actuator check mode (SEE ACTUATOR CHECK
).
c. Press the driver temperature up switch, and change to STEP operation.
d. Press the driver temperature up switch, and check the operation of water valve.
Fig. 133: Checking Actuator

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
DISPLAY CODE - AIR FLOW LEVER POSITION
Display codeAir flow lever position
0SHUT
1SHUT
2SHUT
3OPEN
4OPEN
5OPEN
6OPEN

Fig. 136: Air Vent Mode Damper Control Servomotor Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.PERFORM ACTUATOR CHECK

a. Warm up the engine.
b. Set the actuator check mode (see ACTUATOR CHECK).

Fig. 149: IG Power Source Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.
1.INSPECT FUSE (P-IG)
a. Remove the P-IG fuse from the passenger side J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:

Fig. 168: Rear IG Power Source Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.
1.INSPECT FUSE (RR A/C)
a. Remove the RR A/C fuse from the luggage room J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard: