Lexus RX300 (MCU15). Service manual - part 370

DI–710

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

LEXUS RX300   (RM785E)

DTC

B1231 / 31

Jam protection limit switch circuit on
driver door

DTC

B1233 / 33

Jam protection limit switch circuit on
passenger door

DTC

B1235 / 35

Jam protection limit switch circuit on
rear right door

DTC

B1237 / 37

Jam protection limit switch circuit on
rear left door

CIRCUIT DESCRIPTION

These DTCs are output when a malfunction of limit switch within power wIndow motor is detected.

DTC No.

DTC Detection Condition

Trouble Area

B1231/31

B1233/33

No change in limit switch more than 2.0 seconds even if oper-

ti

l

d

h

li it

it h i OFF

S Jam protection limit switch

B1235/35

ating glass down when limit switch is OFF 

(window glass is fully closed)

Jam  rotection limit switch

S Wireharness

B1237/37

(window glass is fully closed)

HINT:
Please refer to power window control system of BE section for switch inspection, and to each door system
of DI section for wireharness inspection.

DI1SQ–02

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

DI–711

LEXUS RX300   (RM785E)

DTC

B1232 / 32

Jam protection pulse switch circuit on
driver door

DTC

B1234 / 34

Jam protection pulse switch circuit on
passenger door

DTC

B1236 / 36

Jam protection pulse switch circuit on
rear right door

DTC

B1238 / 38

Jam protection pulse switch circuit on
rear left door

CIRCUIT DESCRIPTION

These DTCs are output when a malfunction of pulse switch within power window motor is detected.

DTC No.

DTC Detecting Condition

Trouble Area

B1232/32

B1234/34

No change in pulse switch more than 2.0 seconds even if

i

l

d

h

li it

it h i OFF

S Jam protection pulse switch

B1236/36

opening glass down when limit switch is OFF 

(window glass is fully closed)

Jam  rotection  ulse switch

S Wireharness

B1238/38

(window glass is fully closed).

HINT:
Please refer to power window control system of BE section for switch inspection, and to each door system
of DI section for wireharness inspection.

DI1SR–02

I12721

Body ECU

Wireless Door Lock Tuner

2

PRG

RDA

16

17

LG

LG

L

L

18

IA2

IA2

17

3

B6

B6

PRG

RDA

DI–712

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

LEXUS RX300   (RM785E)

DTC

B1242 / 42

Wireless door lock tuner circuit mal-
function

CIRCUIT DESCRIPTION

This DTC is output when GND short of RDA terminal is detected.

DTC No.

DTC Detecting Condition

Trouble Area

B1242/42

GND short of RDA terminal

S Wireharness

S Wireless door lock tuner

S Body ECU

WIRING DIAGRAM

DI2B7–09

I03347

Tuner

Body No.1
ECU

RDA

I03348

Tuner

Body No.1
ECU

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

DI–713

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

1

Check wireharness.

PREPARATION:
Disconnect the connector of tuner and body ECU.
CHECK:
Check the continuity between wireharness and body ground.
OK:
No continuity.

NG

Repair or replace the wireharness.

OK

2

Check body ECU.

PREPARATION:
Connect the connector of body ECU.
CHECK:
Check the DTC.
OK:
B1242/42 is not output.

NG

Replace the body ECU.

OK

Replace the tuner.