Page 673 of 1807
FI6571
Sub Throttle Position
SensorECM
5V
B+ VCC
VTA2
IDL2
E2
DI-258
- DIAGNOSTICSENGINE (2JZ-GTE)
486 Author: Date:
1997 SUPRA (RM502U)
DTC P1400 Sub Throttle Position Sensor Malfunction
CIRCUIT DESCRIPTION
The sub throttle position sensor is built and operates in the
same way as the main throttle position sensor. This sensor is
used for traction control. The sub throttle valve is opened and
closed by the sub throttle actuator according to signals from the
throttle control ECU to control the engine output.
DTC No.DTC Detecting ConditionTrouble Area
P1400
Condition (a) or (b) continues:
(a) VTA 2 < 0.25 V, and closed sub throttle position switch is
OFF
(b) VTA 2 > 4.9 VOpen or short in sub throttle position sensor circuit
Sub throttle position sensor
ECM
WIRING DIAGRAM
Refer to page DI-184 for the WIRING DIAGRAM.
DI4TE-01
Page 674 of 1807
BE6653P23933A07640A06729
ON
Check Harness A
ECM
B65, 63, 42
VTA2 (+)
IDL2 (+) E2 (-)
Sub Throttle Valve
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-259
487 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check voltage between terminals VTA2, IDL2 and E2 of ECM.
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Turn ignition switch ON.
(c) Remove intake air connector pipe and disconnect sub
throttle valve actuator connector.
CHECK:
Measure voltage between terminals VTA2, IDL2 and E2 of ECM
when the sub throttle valve is opened gradually from the closed
condition.
OK:
Throttle ValveTerminal VTA2Terminal IDL2
Fully Closed0.3 - 0.8 V0 - 3.0 V
Fully Open3.2 - 4.9 V9 - 14 V
HINT:
The voltage should increase steadily in proportion to the throttle
valve opening angle.
OK Check for intermittent problems
(See page DI-147).
NG
Page 675 of 1807
S03246S02441A03142
Sub Throttle Position Sensor
1
2
3
DI-260
- DIAGNOSTICSENGINE (2JZ-GTE)
488 Author: Date:
1997 SUPRA (RM502U)
2 Check sub throttle position sensor.
PREPARATION:
Disconnect sub throttle position sensor connector.
CHECK:
Measure resistance between terminals 3, 2 and 1 of sub throttle
position sensor connector when the sub throttle valve is opened
gradually from the closed condition.
OK:
Throttle ValveTerminal 3 - 1Terminal 2 - 1
Fully Closed0.34 - 6.3 kWLess than 0.5 kW
Fully Open2.0 - 10.8 kW1 MW or higher
HINT:
Resistance between terminals 3 and 1 should increase gradu-
ally in accordance witch the sub throttle valve opening angle.
NG Adjust or replace sub throttle position sensor
(See page SF-44).
OK
3 Check for open and short in harness and connector between ECM and sub
throttle position sensor (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace ECM.
Page 676 of 1807
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-261
489 Author: Date:
1997 SUPRA (RM502U)
DTC P1401 Sub Throttle Position Sensor Range/
Performance Problem
CIRCUIT DESCRIPTION
Refer to ºSub Throttle Position Sensor Malfunctionº on page DI-258.
DTC No.DTC Detecting ConditionTrouble Area
P1401
Condition (a) and (b) continue for 10 sec. or more
(2 trip detection logic)
(a) During driving the road that difficult to slip with ºAUTO
modeº
(b) The difference of the throttle valve open angle and the
sub throttle valve opening angle is greater than 35°
Sub throttle position sensor
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P1401) being output?
YES Go to relevant DTC chart.
NO
Replace sub throttle position sensor.
DI4TF-01
Page 677 of 1807

S03258
Turbo Pressure Sensor
3
2
1L-R
B-Y
W-B41
62
65B
B
BECM
5V
VCC
5V
PM1
E2
E1 DI-262
- DIAGNOSTICSENGINE (2JZ-GTE)
490 Author: Date:
1997 SUPRA (RM502U)
DTC P1405 Turbo Pressure Sensor Circuit Malfunction
CIRCUIT DESCRIPTION
The sensor detects the air intake chamber pressure and converts the pressure reading into a voltage which
is used to control the turbo pressure by the ECM.
If the ECM detects the below diagnosis conditions, it operates the fail safe function to open the waste gate
valve fully.
DTC No.DTC Detecting ConditionTrouble Area
P1405Open or short in turbo pressure sensor circuit
Open or short in turbo pressure sensor circuit
Turbo pressure sensor
ECM
If the ECM detects DTC ºP1405º it operates the fail safe function, keeping the ignition timing and infection
volume constant and making it possible to drive the vehicle.
HINT:
After confirming DTC P1405 use the OBD II scan tool or TOYOTA hand-held tester to confirm the turbo ab-
solute pressure from ºCURRENT DATAº.
Turbo Absolute PressureMalfunction
0 kPaPIM circuit short
130 kPa or more
VC circuit open or short
PIM circuit open
E2 circuit open
WIRING DIAGRAM
DI4TG-01
Page 678 of 1807
BE6653S02442A06730
SST
E1 (-)
B69, 41
VCC (+)
ECM
ON
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-263
491 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Connect the OBD II scan tool or TOYOTA hand-held tester, and read value of
manifold absolute pressure.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Turn ignition switch ON and push the OBD II scan tool or TOYOTA hand-held tester main switch ON.
CHECK:
Read value of turbo absolute pressure on the OBD II scan tool or TOYOTA hand-held tester.
OK:
Same as atmospheric pressure.
OK Check for intermittent problems
(See page DI-147).
NG
2 Check voltage between terminals VCC and E2 of ECM connector.
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals VCC and E2 of ECM con-
nector.
OK:
Voltage: 4.5 - 5.5 V
NG Check and replace ECM (See page IN-28).
OK
Page 679 of 1807
BE6653S02443A03143
ON
SST
ECM
B65, 62
PM1(+)
E2(-)
DI-264
- DIAGNOSTICSENGINE (2JZ-GTE)
492 Author: Date:
1997 SUPRA (RM502U)
3 Check voltage between terminals PM1 and E2 of ECM connector.
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals PM1 and E2 of ECM con-
nector.
OK:
Voltage: 2.3 - 3.0 V
OK Check and replace ECM (See page IN-28).
NG
4 Check for open and short in harness and connector between turbo pressure
sensor and ECM.
NG Repair or replace harness or connector.
OK
Replace turbo pressure sensor.
Page 680 of 1807
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-265
493 Author: Date:
1997 SUPRA (RM502U)
DTC P1406 Turbo Pressure Sensor Circuit Range/
Performance Problem
CIRCUIT DESCRIPTION
Refer to ºTurbo Pressure Sensor Malfunctionº on page DI-262.
DTC No.DTC Detecting ConditionTrouble Area
P1406
Conditions (a) and (b) continue for 5 sec. or more
(2 trip detection logic)
(a) Turbo pressure sensor output < 1.2 V
(b) Mass air flow > 1.3 g/rev
TbP1406Conditions (a) and (b) continue for 5 sec. or more
(2 trip detection logic)
(a) Turbo pressure sensor output > 4.2 V
(b) Mass air flow < 0.45 g/revTurbo pressure sensor
WIRING DIAGRAM
Refer to page DI-262 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P1406) being output?
YES Go to relevant DTC chart.
NO
Replace turbo pressure sensor.
DI4TH-01