05−145
DIAGNOSTICS − SFI SYSTEM (1GR−FE) 05BSI−01
DTC P0504 BRAKE SWITCH ”A”/”B” CORRELATION
CIRCUIT DESCRIPTION
In this system, the signal of the stop lamp switch is used to judge whether the acceleration system is abnor-
mal or not.
The stop lamp switch has a duplex system (signals STP and ST1−) to memorize the abnormality when the
signals of depressing and releasing the brake pedal are detected simultaneously.
HINT:
Normal condition is as shown in the table.
Signal Brake pedal released In transition Brake pedal depressed
STP OFF ON ON
ST1− ON ON OFF
DTC No. DTC Detection Condition Trouble Area
Condition (a), (b) and (c) continue for 0.5 sec. or more:
S Short in stop lamp switch signal circuit
(a) Ignition switch ON
P0504 S Stop lamp switch
(b) Brake pedal released
S ECM
(c) STP signal is OFF when the ST1− signal is OFF
LAND CRUISER PRADO Supplement (RM1017E)
05−146
DIAGNOSTICS − SFI SYSTEM (1GR−FE)
WIRING DIAGRAM
G−R (*1)
R−L ECM
G−R G−R (*1) 5 12
(*2) R−L R−L
4 2 IM1 E9 ST1−
S18 G−Y (*1) G−Y
Stop G (*1) Driver
ECU−IG
Lamp
Side
24 IE 12 IJ (LHD) J23 D
From
Fuse
Switch
J/B
(RHD) J16 C
B−O 3 G−Y 1
B A
J5 J9 J/C
J/C J/C B−R 16 IF G−Y (LHD) J23 D
B A G−Y (RHD) (RHD) J16 C
G−R (LHD)
(*1) B−O G−Y G−Y G−Y
G−Y
G−R 2 2 2 ID2 (RHD)
(RHD) (LHD)
(*2) B A1
DAC 1
From IGN 5
2 Relay
Fuse
Light
Mount Stop
To High
4 B J29 B
2
STOP Engine J/C
1 3 2
Room
2 R/B
ALT G−Y G−Y
1
Rear Combination Light RH
R15
Rear Combination Light LH
2 2 R13
2 G−Y Engine
Room
G−Y (*1) LG 6 6
W R/B
(*1)
Stop
Stop
20
D J8
2 STPO
Engine J/C 5 5
Room
F J7 F J7 S14
R/B
2 Skid
Control ECU
J17 W−B W−B
G−Y G−Y
B 18 J/C
G−Y D G−Y 19
D
IM1 E9 STP
A A
J31
Battery J/C
*1: w/ VSC BR
*2: w/o VSC
A80358
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand−held tester, as freeze frame data records the engine conditions
when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was
running or stopped, the engine was warmed up or not, the air−fuel ratio was lean or rich, etc. at the time of
the malfunction.
LAND CRUISER PRADO Supplement (RM1017E)
05−147
DIAGNOSTICS − SFI SYSTEM (1GR−FE)
1 CHECK OPERATION OF STOP LIGHT
(a) Check if the stop lights go on and off normally when the brake pedal is depressed and released.
NG REPAIR OR REPLACE STOP LAMP SWITCH
CIRCUIT
OK
2 INSPECT STOP LAMP SWITCH ASSY
(a) Check for continuity between each pair of terminals.
Free Pushed in Standard:
2 1
Switch position Terminal No. Specified condition
1−2 Continuity
Switch pin free
3−4 No continuity
1−2 No continuity
Switch pin pushed in
3−4 Continuity
4 3
A72924 NG REPLACE STOP LAMP SWITCH ASSY
OK
3 READ VALUE OF HAND−HELD TESTER(STP SIGNAL AND ST1− VOLTAGE)
(a) Turn the ignition switch ON.
Brake Pedal Brake Pedal
(b) Select the item ”DIAGNOSIS / OBD/MOBD / DATA LIST
Depressed Released / ALL / STOP LIGHT SW” and read its value displayed on
the hand−held tester.
Standard:
Brake Pedal Specified condition
Depressed STP Signal ON
Released STP Signal OFF
(c) Measure the voltage between the terminals of the E9 and
E13 ECM connectors.
E1 (−) ST1− (+) Standard:
Symbols (Terminal No.) Brake pedal Specified condition
ST1− (E9−1
ST1 (E9 12)
2) Depressed Below 1.5 V
− E1 (E13−1) Released 7.5 to 14 V
E13 E9
ECM Connector
A72880 OK CHECK FOR INTERMITTENT PROBLEMS
(See page 05−7)
NG
LAND CRUISER PRADO Supplement (RM1017E)
05−148
DIAGNOSTICS − SFI SYSTEM (1GR−FE)
4 CHECK HARNESS AND CONNECTOR(STOP LAMP SWITCH − ECM)
Wire Harness Side (a) Disconnect the stop lamp switch connector.
S18 (b) Disconnect the E9 ECM connector.
(c) Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.) Specified condition
Stop lamp switch (S18−1) − STP (E9−19)
Continuity
Stop Lamp Switch Connector Stop lamp switch (S18−4) − ST1− (E9−12)
A56986 Standard (Check for short):
Symbols (Terminal No.) Specified condition
Stop lamp switch (S18−1) or STP (E9−19) − Body ground
No continuity
Stop lamp switch (S18−4) or ST1− (E9−12) − Body ground
E9
ST1− STP
ECM Connector
A67404 NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
CHECK AND REPLACE ECM (See page 01−35)
LAND CRUISER PRADO Supplement (RM1017E)
