Lexus RX300 (MCU15). Service manual — part 118

I04485

–

BODY ELECTRICAL

POWER SOURCE

BE–19

LEXUS RX300 (RM785E)

RR DEF

37 – Ground

39 – Ground

40 – Ground

41 – Ground

IG switch ON

Constant

Constant

Constant

Battery voltage

Continuity

Continuity

Battery voltage

MG CLT

42 – Ground

45 – Ground

IG switch ON

IG switch ON

Battery voltage

Battery voltage

HORN

46 – Ground

47 – Ground

49 – Ground

Constant

Horn switch ON

Constant

Battery voltage

Continuity

Battery voltage

EFI

51 – Ground

53 – Ground

Constant

Constant

Continuity

Battery voltage

If the circuit is as specified, inspect the circuits connected to other parts.
2.

INSPECT FUSIBLE LINK BLOCK CIRCUIT

Remove the fuse from the fusible link and inspect the connector on the fusible link side.

Fuse

Tester connection

Condition

Specified condition

ABS

2 – Ground

Constant

Battery voltage

ALT

4 – Ground

Constant

Battery voltage

RDI

5 – Ground

Constant

Battery voltage

CDS

7 – Ground

Constant

Battery voltage

RR DEF

9 – Ground

Constant

Battery voltage

HEATER

11 – Ground

Constant

Battery voltage

If the circuit is as specified, inspect the circuits connected to other parts.

I04486

BE–20

–

BODY ELECTRICAL

POWER SOURCE

LEXUS RX300 (RM785E)

3.

INSPECT RELAY BLOCK NO. 2 (Inside Engine Room Junction Block) CIRCUIT

(a)

Remove the fuse from the relay block No. 2 and inspect the connector on the relay block side.

Fuse

Tester connection

Condition

Specified condition

H–LP R UPR

2 – Ground

H–LP L UPR

Light control switch HEAD and headlight dimmer

switch HIGH beam

Battery voltage

A/F HTR

5 – Ground

Constant

Battery voltage

If the circuit is as specified, inspect the circuit connected to other parts.
(b)

Remove the relay from the relay block No. 2 and inspect the connector on the relay block side.

Relay

Tester connection

Condition

Specified condition

ABS SOL

6 – Ground

7 – Ground

Constant

Constant

Battery voltage

Continuity

FAN No.3

12 – Ground

15 – Ground

Constant

IG switch ON

Battery voltage

Battery voltage

FAN No.1

16 – Ground

19 – Ground

Constant

IG switch ON

Battery voltage

Battery voltage

ABS MOTOR

20 – Ground

Constant

Battery voltage

FAN No.2

24 – Ground

28 – Ground

Constant

IG switch START

Continuity

Battery voltage

A/F HEATER

30 – Ground

32 – Ground

Constant

Constant

Continuity

Battery voltage

If the circuit is as specified, inspect the circuit connected to other parts.

I04487

–

BODY ELECTRICAL

POWER SOURCE

BE–21

LEXUS RX300 (RM785E)

4.

INSPECT ENGINE ROOM RELAY BLOCK NO. 3 CIRCUIT (LHD)

Remove the relay from the engine room relay block No. 3 and inspect the connector on the relay block side.

Relay

Tester connection

Condition

Specified condition

DRL No. 2

3 – Ground

5 – Ground

Constant

Constant

Battery voltage

Battery voltage

If the circuit is as specified, inspect the circuit connected to other parts.

I04488

BE–22

–

BODY ELECTRICAL

POWER SOURCE

LEXUS RX300 (RM785E)

5.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK CIRCUIT

(a)

Remove the fuse from the instrument panel junction block and inspect the connector on the junction
block side.

Fuse

Tester connection

Condition

Specified condition

AM1

1 – Ground

Constant

Battery voltage

POWER

3 – Ground

Constant

Battery voltage

IGN

5 – Ground

IG switch ON

Battery voltage

RADIO No. 2

8 – Ground

IG switch ON

Battery voltage

CIG

10 – Ground

IG switch ACC

Battery voltage

PWR OUTLET

14 – Ground

Constant

Battery voltage

FR FOG

15 – Ground

Constant

Battery voltage

SRS–ACC

17 – Ground

IG switch ACC

Battery voltage

ECU–IG

20 – Ground

IG switch ON

Battery voltage

WIPER

21 – Ground

IG switch ON

Battery voltage

P RR DOOR

24 – Ground

Constant

Battery voltage

P FR DOOR

25 – Ground

Constant

Battery voltage

S/ROOF

27 – Ground

Constant

Battery voltage

HEATER

29 – Ground

IG switch ON

Battery voltage