TOYOTA SUPRA 1997 Service Repair Manual

DI-276
- DIAGNOSTICSENGINE (2JZ-GTE)
504 Author
: Date
:
1997 SUPRA (RM502U)
5 Check for open and short in harness and connector between EFI main relay
(Marking: EFI MAIN) and ECM (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN-28).
6 Check connection of vacuum hose (See page EC-2).
NG Repair or replace.
OK
7 Check operation of waste gate valve (See page TC-18).
NG Replace No.1 turbocharger.
OK
8 Check operation of exhaust bypass valve (See page TC-18).
NG Replace No.2 turbocharger.
OK
Check and replace ECM (See page IN-28).

BE6653S05421
A03144
ON
Check Harness A
VSV3 (+)
VSV4 (+)
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-277
505 Author
: Date
:
1997 SUPRA (RM502U)
OBDII scan tool (excluding TOYOTA hand-held tester)
1 Check VSV for waste gate valve (See page SF-63).
NG Replace VSV for waste gate valve.
OK
2 Check VSV for exhaust bypass valve (See page SF-67).
NG Replace VSV for exhaust bypass valve.
OK
3 Check voltage between terminal VSV3, VSV4 of ECM connector and body
ground.
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminal VSV3, VSV4 of ECM con-
nector and body ground.
OK:
Voltage: 9 - 14 V
NG Check and repair harness or connector be-
tween VSV for waste gate valve and ECM
(See page IN-28).
OK

DI-278
- DIAGNOSTICSENGINE (2JZ-GTE)
506 Author
: Date
:
1997 SUPRA (RM502U)
4 Check connection of vacuum hose (See page EC-2).
NG Repair or replace.
OK
5 Check operation of waste gate valve (See page TC-18).
NG Replace No.1 turbocharger.
OK
6 Check operation of exhaust bypass valve (See page TC-18).
NG Replace No.2 turbocharger.
OK
Check and replace ECM (See page IN-28).

S05426
From
BatteryR/B
No.2 2
2A
ALT
R/B
No.2
POWER
22W-L
J/B No.1 210
1B 1ESTOP
WStop Light
Switch
21G-W11
IJ1G-W4
A
STPECM
J/B
No.1 1
101H
1C
Light
Failure
Sensor
To Stop LightG-W
7
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-279
507 Author
: Date
:
1997 SUPRA (RM502U)
DTC P1520 Stop Light Switch Signal Malfunction
Only for A/T
CIRCUIT DESCRIPTION
This signal is used to detect when the brakes have been applied. The STP signal voltage is the same as
the voltage supplied to the stop lights.
The STP signal is used mainly to control the fuel cut-off engine speed. (The fuel cut-off engine speed is
reduced slightly when the vehicle is braking.)
DTC No.DTC Detecting ConditionTrouble Area
P1520
The stop light switch does not turn off even once the vehicle is
driven.
(2 trip detection logic)
Short in stop light switch signal circuit

Stop light switch

ECM
WIRING DIAGRAM
DI4TK-01

A00726
ON
ONBrake Pedal
DepressedBrake Pedal
Released
Check Harness A
ECM
A4
STP(+)
DI-280
- DIAGNOSTICSENGINE (2JZ-GTE)
508 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check operation of stop light.
PREPARATION:
Check if the stop lights go on and off normally when the brake
pedal is operated and released.
NG Check and repair stop light circuit.
OK
2 Check STP signal.
When using TOYOTA hand-held tester:
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn the ignition switch ON and TOYOTA hand-held tes-
ter main switch ON.
CHECK:
Read the STP signal on the TOYOTA hand-held tester.
OK:
Break pedal is depressed: STP ... ON
Break pedal is released: STP ... OFF
When not using TOYOTA hand-held tester:
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Turn ignition switch ON.
CHECK:
Check voltage between terminal STP of ECM and body ground.
OK:
Brake pedalVoltage
Depressed7.5 - 14 V
ReleasedBelow 1.5 V
OK Check for intermittent problems
(See page DI-147).
NG

- DIAGNOSTICSENGINE (2JZ-GTE)
DI-281
509 Author
: Date
:
1997 SUPRA (RM502U)
3 Check harness and connector between ECM and stop light switch
(See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace ECM.

FI6878
R/B No.2
EFI No.1 2A2 1
Battery
B
B-Y
EA14
B-Y33
AECM
BATT DI-282
- DIAGNOSTICSENGINE (2JZ-GTE)
510 Author
: Date
:
1997 SUPRA (RM502U)
DTC P1600 ECM BATT Malfunction
CIRCUIT DESCRIPTION
Battery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is OFF for
use by the DTC memory and air-fuel ratio adaptive control value memory, etc.
DTC No.DTC Detecting ConditionTrouble Area
P1600Open in back up power source circuit
Open in back up power source circuit

ECM
HINT:
If DTC P1600 appear, the ECM does not store another DTC.
WIRING DIAGRAM
DI4TL-01

A00727
LOCK
Check Harness A
ECM
A33
BATT(+)
N08419
EFI FuseR/B No.2
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-283
511 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check voltage between terminal BATT of ECM connector and body ground.
PREPARATION:
Connect Check Harness A (See page DI-164).
CHECK:
Measure voltage between terminal BATT of ECM connector
and body ground.
OK:
Voltage: 9 - 14 V
OK Check and replace ECM (See page IN-28).
NG
2 Check EFI fuse.
PREPARATION:
Remove EFI fuse from R/B No.2.
CHECK:
Check continuity of EFI fuse.
OK:
Continuity
NG Check for short in all the harness and compo-
nents connected to EFI fuse.
OK
Check and repair harness or connector be-
tween battery, EFI fuse and ECM.

DI-284
- DIAGNOSTICSENGINE (2JZ-GTE)
512 Author
: Date
:
1997 SUPRA (RM502U)
DTC P1605 Knock Control CPU Malfunction
CIRCUIT DESCRIPTION
Refer to Knock Sensor 1, 2 Circuit Malfunction on page DI-209.
DTC No.DTC Detecting ConditionTrouble Area
P1605Engine control computer malfunction
(for knock contorl)
ECM
WIRING DIAGRAM
Refer to page DI-209 for WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P1605) being output?
YES Go to relevant DTC chart.
NO
Check and replace ECM. (See page IN-28).
DI4TM-01

S03451
ECM
EFI+
EFI-
ETC+
ETC-27
26
14
13A
A
A
AB
W
Y
W-RThrottle Control ECU
EFI+
EFI-
GE11
ETC+
ETC-
GE12
T15
T15
T15
T15
T15
T15
7
20
15
8
21
14
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-285
513 Author
: Date
:
1997 SUPRA (RM502U)
DTC P1630 Traction Control System Malfunction
CIRCUIT DESCRIPTION
This circuit is used send TRAC control information from throttle control ECU to the ECM (ETC+, ETC-), and
engine control information from the ECM to the throttle control ECU (EFI+, EFI-).
DTC No.DTC Detecting ConditionTrouble Area
P1630
Condition (a) or (b) continued for 5 sec. or more
(a) No EFI ± data is received from the ECM.
(b) A signal is received from the ECM indicating trouble in
TRAC.
Open or short in ETC+ or ETC- circuit

Open or short in EFI+ or EFI- circuit

Throttle control ECU

ECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
When TRAC OFF indicator is OFF, there is a problem in the EFI ± circuit, and when the TRAC OFF indicator
is ON, there is problem in the ETC ± circuit.
1 Check TRAC system (See page DI-501).
NG Repair or replace TRAC systems.
OK
DI4TN-01