Lexus RX300 (MCU15). Service manual - part 302

AB0117 AB0119

H05060

H16269

LOCK

ON

AB0119

H10688

H10654

ON

CG

Tc

(+)

(–)

DI–440

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE
If the DTC is not displayed, do the following troubleshooting.

1

Does SRS warning light light up for approx. 6 seconds?

PREPARATION:
Check operation of the SRS warning light after ignition switch
is turned from LOCK position to ON position.

NO

Check SRS warning light system (See page 
DI–434).

YES

2

Check voltage between terminals Tc and CG of DLC3.

PREPARATION:
Turn the ignition switch to ON.
CHECK:
Measure the voltage between terminals Tc and CG of DLC3.
OK:

Voltage: 10 – 14 V

OK

Go to step 4.

NG

AB0119

H10689

H10656

ON

Tc

(+)

(–)

AB0117 AB0119
H01302

H12918

LOCK

ON

Airbag Sensor Assembly

Tc

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–441

LEXUS RX300   (RM785E)

3

Check voltage between terminal Tc of DLC3 and body ground.

CHECK:
Measure the voltage between terminal Tc of DLC3 and body
ground.
OK:

Voltage: 10 – 14 V

OK

Check harness between terminal E1 of DLC3
and body ground.

NG

4

Check airbag sensor assembly.

PREPARATION:
(a)

Turn the ignition switch to LOCK.

(b)

Disconnect negative (–) terminal cable from the battery,
and wait at least for 90 seconds.

(c)

Disconnect the airbag sensor assembly connector.

(d)

Insert service wire into terminal Tc from back side as
shown in the illustration.

(e)

Connect the airbag sensor assembly connector with ser-
vice wire.

(f)

Connect negative (–) terminal cable to the battery.

(g)

Turn the ignition switch to ON and wait at least for 20 se-
conds.

(h)

Connect service wire of terminal Tc to body ground.

CHECK:
Check operation of the SRS warning light.
OK:

SRS waning light comes on.

NOTICE:
Pay due attention to the terminal connecting position to
avoid a malfunction.

OK

Check harness between the airbag sensor as-
sembly and DLC3.

NG

Replace airbag sensor assembly.

AB0119
H01304

H01305

LOCK

Airbag Sensor Assembly

Tc

(+)

(–)

DI–442

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

LEXUS RX300   (RM785E)

If the DTC is displayed without a DTC check procedure, perform the following
troubleshooting.

1

Check resistance between terminal Tc of airbag sensor assembly and body
ground.

PREPARATION:
(a)

Turn the ignition switch to LOCK.

(b)

Disconnect negative (–) terminal cable from the battery,
and wait at least for 90 seconds.

(c)

Disconnect the airbag sensor assembly connector.

CHECK:
Check resistance between terminal Tc of the airbag sensor as-
sembly connector and body ground.
OK:

Resistance: 1 MΩ or Higher

NG

Repair or replace harness or connector.

OK

Replace airbag sensor assembly.

DI611–05

Customer Problem Analysis

Vehicle Brought to Workshop

Problem Symptom Confirmation

Symptom Simulation

Symptom does not occur

Problem Symptom Table

Circuit Inspection

Identification of Problem

Repair

Confirmation Test

End

Titles inside

are titles of pages in this

manual with the page number indicated in the
bottom portion.      See the indicated pages
for detailed explanations.

1

2

3

4

5

7

Step 5, 7 : Diagnostic steps permitting the use of the

hand–held tester and break–out–box.

P. DI–444

P. DI–444

P. IN–22

P. DI–453 – DI–470

Symptom occur

6

–

DIAGNOSTICS

THEFT DETERRENT SYSTEM

DI–443

LEXUS RX300   (RM785E)

THEFT DETERRENT SYSTEM

HOW TO PROCEED WITH TROUBLESHOOTING

HINT:
Troubleshooting  of the theft deterrent system is based on the premise that the door lock control system is
operating normally. Accordingly, before troubleshooting the theft deterrent system, first make certain that
the door lock control system is operating normally.
For troubleshooting use a volt/ohm meter.
Be sure to use troubleshooting procedure appropriate to the diagnostic tool being used.
Perform troubleshooting in accordance with the procedure on the following page.