1995 TOYOTA SUPRA sensor

DTC 51 Switch Condition Signal Circuit
CIRCUIT DESCRIPTION
Park/Neutral Position Switch
The ECM uses the signals from the park/neutral position switch to determine whether the transmission is in park
or neutral, or in some other position.
Air Conditioning Switch Signal
The ECM uses the output from the air conditioning switch to determine whether or not the air conditioning is
operating so that it can increase the idling speed of the engine if necessary.
Throttle Position Sensor IDL Signal
The IDL contacts are mounted in the throttle position sensor, and detects the idle condition.
 DTC No. Diagnostic Trouble Code Detecting Condition Trouble Area
 
 
 
 
 
 
51
 
 
 
 
 
 
(1) 3 sec. or more after engine starts with
closed throttle position switch OFF
(IDL1)
(2) Park/neutral position switch: OFF
(Shift position in ºRº, ºDº, º2º or º1º
position.)
(3) A/C switch ON 
 
 
 
 
 

Throttle position sensor IDL circuit

Accelerator pedal and cable

Park/neutral position switch

A/C switch circuit

ECM
HINT: In this circuit, diagnosis can only be made in the test mode.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±571

INSPECTION PROCEDURE
PNP...Go to page EG±574.
(See page EG±514).
Setting the test mode.
(1) Turn ignition switch OFF.
(2) Connect terminals TE2 and E1 of DLC2.
(3) Turn ignition switch ON.
(For checking terminal IDL, disconnect the
vacuum hose from the throttle body, then ap-
ply vacuum to the throttle opener (See page
EG±292)).
((For checking terminal A/C, start the engine.)
(4) connect terminals TE1 and E1 of DLC2.
Check if code ª51º is output by the malfunction indi-
cator lamp.
*: Before the STA signal is input (ST is not ON), diag±
nostic trouble code 43 is also output.
Diagnostic trouble code 42 is output with vehicle speed
5 km/h (3 mph) or below.
Check output condition of diagnostic trouble code 51.
IDL1...Go to step [2].
PNP....Go to page Eg±574.
A/C....Go to step [3].
Proceed to next circuit inspection shown on matrix
chart (See page Eg±514).
Check output condition of diagnostic trouble code 51.
Throttle Position
Sensor (IDL1)
Condition
Park/Neutral Posi-
tion Switch (PNP)
Code
Accelerator pedal
released
Accelerator pedal
depressed
A/C SW ON
A/C SW OFFA/C Switch (A/C)
P or N position
R, D, 2 or L position
EG±572± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

(See page EG±292)
(See page EG±510)
(See page AC±62)
(1) Remove throttle body.
(See page EG 291)
(2) Apply vacuum to throttle opener.
(See page EG±292)
Measure resistance between terminals 3 (IDL1)
and 4 (E2) of throttle position sensor connector.
Check throttle position sensor.
Check voltage between terminal A/C of engine control module connector and
body ground.
Adjust or replace throttle position sensor.
(See page EG±292)
Check and repair harness or connector between en-
gine control module and throttle position sensor.
(1) Connect SST (check harness ªAº).
(See page EG±510)
SST 09990±01000
(2) Start the engine.
Measure voltage between terminal A/C of engine
control module and body ground.
Check A/C compressor circuit.
(See page EG±62)
Check and replace engine control module.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±573

TURBOCHARGER
On±Vehicle Inspection
1. INSPECT INTAKE AIR SYSTEM
Check for leakage or clogging between the air cleaner and
turbocharger inlet and between the turbocharger outlet and
cylinder head.
wClogged air cleaner .... Clean or replace air filter
wHoses collapsed or deformed .... Repair or replace
wLeakage from connections .... Check each
connection and repair
wCracks in components Check and replace
2. INSPECT EXHAUST SYSTEM
Check for leakage or clogging between the cylinder head and
turbocharger inlet and between the turbocharger outlet and
exhaust pipe.
wDeformed components Repair or replace
wForeign material in passages Remove
wLeakage from components Repair or replace
wCracks in components Check and replace
3. INSPECT EXHAUST EXHAUST GAS CONTROL VALVE
OPERATION
(a) Disconnect the air hose from the actuator.
(b) Using SST, apply approx. 49 kPa (0.50 kgf/cm
2, 7.1 psi) of
pressure to the actuator.
SST 09992±00241
(c) Check that the actuator push rod moves.
(d) Reconnect the air hose to the actuator.
If operation is not as specified, replace the control valve as-
sembly.
4. INSPECT TURBOCHARGING PRESSURE
(a) Using a 3±way connector, connect SST (turbocharger
pressure gauge) to the hose between the gas filter and turbo
pressure sensor.
SST 09992±00241
(b) While driving with the engine running at 5,600 rpm or more
with the throttle valve fully open in the 1st gear/ L range,
check the turbocharging pressure.
Standard pressure:
61±75 kPa (0.62±0.76 kgf/cm
2, 8.8±10.8 psi)
If the pressure is less than that specified, check the intake
and exhaust systems for leakage. If there is no leakage, re-
place the turbocharger assembly.
If the pressure is above specification, check if the actuator
hose is disconnected or cracked. If not, replace the turbo-
charger assembly. EG±144
± ENGINETURBOCHARGER SYSTEM (2JZ±GTE)

VSV for Intake Air Control Valve
(See SFI System)
VSV for Waste Gate Valve
(See SFI System)
VSV for Exhaust Gas Control Valve
(See SFI System)
VSV for Exhaust Bypass Valve
(See SFI System)
Turbo Pressure Sensor
(See SFI System)
± ENGINETURBOCHARGER SYSTEM (2JZ±GTE)EG±145

17. REMOVE VSV ASSEMBLY
(a) Disconnect these hoses:
(1) Air hose from actuator for waste gate valve
(2) Air hose from actuator for exhaust gas control valve
(3) Air hose from hose clamp
(4) Engine wire from wire clamp
(b) Remove the 2 bolts.
(c) Disconnect the 2 VSV connectors, and remove the VSV
assembly.
18. REMOVE AIR TUBES AND INTAKE AIR CONNECTOR
(a) Disconnect the connector and hoses:
(1) Crankshaft position sensor connector from clamp
(2) Water bypass hose (from water pump) from No.1 turbo
water pipe
(3) Water bypass hose (from water outlet) from No.1 turbo
water pipe
(4) Water bypass hose (from water outlet) from No.2 turbo
water pipe
(b) Remove the bolt, and disconnect the No.2 turbo water pipe
from the No.4 air tube.
(c) Remove the 2 bolts, and disconnect the No.1 air tube from
the No.1 turbocharger. Remove the gasket.
INSTALLATION HINT: Use a new gasket.
Torque: 21 NVm (210 kgfVcm, 15 ftVlbf)
(d) Remove the 2 bolts holding the No.4 air tube to the No.1
turbocharger. Remove the gasket.
INSTALLATION HINT: Use a new gasket.
Torque: 21 NVm (210 kgfVcm, 15 ftVlbf)
(e) Disconnect these hoses, and remove the No.4 air tube and
air bypass valve assembly.
(1) Air hose from No.4 air tube
(2) Air hose from intake air connector
± ENGINETURBOCHARGER SYSTEM (2JZ±GTE)EG±153

23. REMOVE MAIN HEATED OXYGEN SENSOR
(a) Disconnect the oxygen sensor connector.
(b) Remove the 2 nuts, oxygen sensor and gasket.
INSTALLATION HINT: Use a new gasket and 2 new nuts.
Torque: 20 NVm (200 kgfVcm, 14 ftVlbf)
24. REMOVE EXHAUST GAS CONTROL VALVE
Remove the 3 nuts, control valve and 2 gaskets.
NOTICE: The control valve is ceramic. Do not drop or knock
the control valve.
INSTALLATION HINT: Use 2 new gaskets and 3 new nuts.
Torque: 69 NVm (700 kgfVcm, 51 ftVlbf)
25. REMOVE NO.1 TURBOCHARGER STAY
Remove the bolt, nut and turbocharger stay.
Torque: 43 NVm (440 kgfVcm, 32 ftVlbf)
26. REMOVE NO.2 TURBOCHARGER STAY
Remove the bolt, nut and turbocharger stay.
INSTALLATION HINT: Install the turbocharger stay and No.1
turbo oil pipe clamp with the bolt and nut.
Torque: 43 NVm (440 kgfVcm, 32 ftVlbf)
27. REMOVE NO.1 TURBO OIL PIPE
(a) Remove the union bolt holding the turbo oil pipe to the
cylinder block. Remove the 2 gaskets.
INSTALLATION HINT: Use 2 new gaskets.
Torque: 39 NVm (400 kgfVcm, 29 ftVlbf)
(b) Remove the 2 nuts, and disconnect the turbo oil pipe from
turbocharger. Remove the gasket.
INSTALLATION HINT:
wUse a new gasket.
wAlign the oil holes of the gasket and turbocharger
housing.
Torque: 21 NVm (210 kgfVcm, 15 ftVlbf)
(c) Disconnect the turbo oil hose from the turbo oil outlet on the
No.1 oil pan, and remove the turbo oil pipe.
28. REMOVE NO.2 TURBO OIL PIPE
(a) Remove the union bolt holding the turbo oil pipe to the
cylinder block. Remove the 2 gaskets.
INSTALLATION HINT: Use 2 new gaskets.
Torque: 39 NVm (400 kgfVcm, 29 ftVlbf)
± ENGINETURBOCHARGER SYSTEM (2JZ±GTE)EG±155

SERVICE SPECIFICATIONS
SERVICE DATA
 
 
 
Turbocharger 
 
 
Turbocharging pressure
Impeller wheel axial play Limit
Impeller wheel radial play Limit 
 
 
61±75 kPa (0.62±0.76 kgf/cm2, 8.8±10.8 psi)
0.162 mm (0.0064 in.)
0.110 mm (0.0045 in.)
TORQUE SPECIFICATIONS
 
 Part tightened 
 NVm 
 kgfVcm 
 ftVlbf
 Turbocharger x Turbine outlet elbow 25 250 18
 Turbo water pipe x Turbocharger 8.8 90 78 in.Vlbf
 Side bearing housing plate x Turbocharger 8.8 90 78 in.Vlbf
 No.2 air tube x No.2 turbocharger 21 210 15 
 Turbocharger x Exhaust manifold
 
 54
 
 550
 
 40
 Turbo oil pipe x Turbocharger 21 210 15
 Turbo oil pipe x Cylinder block 39 400 29
 Turbocharger stay x Turbocharger 43 440 32 
 Turbocharger stay x Cylinder block
 
 43
 
 440
 
 32
 Exhaust gas control valve x Turbine outlet elbow 69 700 51
 Main heated oxygen sensor x Exhaust gas control valve 20 200 14
 Exhaust gas control valve stay x Exhaust gas control valve 43 440 32 
 Exhaust gas control valve stay x Cylinder block
 
 43
 
 440
 
 32
 Exhaust bypass pipe x Turbine outlet elbow 25 250 18
 Exhaust bypass pipe x Exhaust gas control valve 25 250 18
 Intake air control valve x No.2 turbocharger 21 210 15 
No.4 air tube x No.1 turbocharger 
21 
210 
15 
 No.1 air tube x No.1 turbocharger
 
 21
 
 210
 
 15
 No.2 front exhaust pipe x Exhaust gas control valve 62 630 46
 Front exhaust pipe x No.2 front exhaust pipe 58 590 43
 Pipe support bracket x Transmission 43 440 32 
 
 
Upper front crossmember extension x Front suspension Bolt
Nut
 
 
 
29
33
 
 
 
300
340
 
 
 
22
25
 
 
Front lower arm bracket stay x Front suspension Bolt
Nut 
 
44
59 
 
450
600 
 
33
43
 CAC duct x CAC 4.9 50 43 in.Vlbf
 CAC x Body 13 135 10
EG±162± ENGINETURBOCHARGER SYSTEM (2JZ±GTE)