TOYOTA SUPRA 1997 Service Repair Manual

DI-166
- DIAGNOSTICSENGINE (2JZ-GTE)
394 Author
: Date
:
1997 SUPRA (RM502U)
IG switch ON9 - 14
#50 (B16) - E01 (B80)R e BRIdlingPulse generation
(See page DI-204)
IG switch ON9 - 14
#60 (B15) - E01 (B80)R-B e BRIdlingPulse generation
(See page DI-204)
IG switch ON- 0.1 - 0.5
IGT1 (B57) - E1 (B69)R-W e BRIdlingPulse generation
(See page DI-252)
IG switch ON- 0.1 - 0.5
IGT2 (B56) - E1 (B69)W-R e BRIdlingPulse generation
(See page DI-252)
IG switch ON- 0.1 - 0.5
IGT3 (B55) - E1 (B69)LG e BRIdlingPulse generation
(See page DI-252)
IG switch ON- 0.1 - 0.5
IGT4 (B54) - E1 (B69)B-R e BRIdlingPulse generation
(See page DI-252)
IG switch ON- 0.1 - 0.5
IGT5 (B53) - E1 (B69)L e BRIdlingPulse generation
(See page DI-252)
IG switch ON- 0.1 - 0.5
IGT6 (B52) - E1 (B69)R e BRIdlingPulse generation
(See page DI-252)
IG switch ON4.5 - 5.5
IGF (B58) - E1 (B69)R-Ye BRIdlingPulse generation
(See page DI-252)
G1 (B26) - G1
(B6)W e OIdlingPulse generation
(See page DI-215)
G2 (B25) - NE
(B7)B-W e BRIdlingPulse generation
(See page DI-215)
NE (B27) - NE
(B7)B-R e BRIdlingPulse generation
(See page DI-215)
M-REL (A24) - E1 (B69)GR e BRIG switch ON9 - 14
IG switch ONBelow 0.5
FPC (A22) - E1 (B69)V-W e BRIdlingPulse generation
(4.0 - 5.5)
DI (A21) - E1 (B69)G e BRIdling7.0 or more
EVAP (B74) - E01 (B80)V e BRIG switch ON9 - 14
EGR (B75) - E01 (B80)P e BRD posiiton stall rpm: 1,600 ~ 1,800 rpmPulse generation or
Below 2.0
EGR (B75) E01 (B80)P e BR
Idling9 - 14
ISC1 (B35) - E01 (B80)V-Y e BRIdling, When A/C Switch ON or OFFPulse generation
(See page DI-240)
ISC2 (B34) - E01 (B80)G-W e BRIdling, When A/C Switch ON or OFFPulse generation
(See page DI-240)
ISC3 (B33) - E01 (B80)G-O e BRIdling, When A/C Switch ON or OFFPulse generation
(See page DI-240)

- DIAGNOSTICSENGINE (2JZ-GTE)
DI-167
395 Author
: Date
:
1997 SUPRA (RM502U) ISC4 (B32) - E01 (B80)
R-G e BRIdling, When A/C Switch ON or OFFPulse generation
(See page DI-240)
OX1 (B48) - E1 (B69)W e BRMaintain engine speed at 2,500 rpm for 2 min. after warning upPulse generation
(See page DI-193)
OXS (B47) - E1 (B69)R-L e BRMaintain engine speed at 2,500 rpm for 2 min. after warning upPulse generation
(See page DI-193)
HT1 (B71) E01 (B80)BLBRIdling after warning upBelow 3.0HT1 (B71) - E01 (B80)B-L e BRIG switch ON9 - 14
HTS (B72) E01 (B80)BR WBRIdling after warning upBelow 3.0HTS (B72) - E01 (B80)BR-W e BRIG switch ON9 - 14
KNK1 (B50) - E1 (B69)W e BRIdlingPulse generation
(See page DI-212)
KNK2 (B49) - E1 (B69)W e BRIdlingPulse generation
(See page DI-212)
NSW (B76) E1 (B69)BWBR
IG switch ON
Other shift position in ºPº or ºNº position9 - 14
NSW (B76) - E1 (B69)B-W e BRIG switch ON
Shift position in ºPº or ºNº position0 - 3.0
SPD (A2) - E1 (B69)P e BRIG switch ON
Rotate driving wheel slowlyPulse generation
(See page DI-238)
TE1 (A20) - E1 (B69)L e BRIG switch ON9 - 14
W (A6) E1 (B69)LBBRIdling9 - 14W (A6) - E1 (B69)L-B e BRIG switch ON0 - 3.0
OD1 (A12) - E1 (B69)BR-B e BRIG switch ON9 - 14
AC1 (A34) E1 (B69)LRBRA/C switch ON (At idling)0 - 1.5AC1 (A34) - E1 (B69)L-R e BRA/C switch OFF7.5 - 14
ACMG (A23) E01 (B80)WGBRA/C switch ON (At idling)0 - 3.0ACMG (A23) - E01 (B80)W-G e BRA/C switch OFF9 - 14
FPU (B73) E01 (B80)WLBRIG switch ON9 - 14FPU (B73) - E01 (B80)W-L e BRRestarting at high engine coolant temp.Below 2.0
ELS (A15) E1 (B69)RYBRDefogger switch or taillight switch ON7.5 - 14ELS (A15) - E1 (B69)R-Y e BRDefogger switch and taillight switch OFF-0.1 - 1.5
SDL (A8) - E1 (B69)G e BRDuring transmissionPulse generation
VSV1 (B40) E1 (B69)GBBRImmediately after racingBelow 3.0VSV1 (B40) - E1 (B69)G-B e BRIdling9 - 14
VSV2 (B39) E1 (B69)GYBRFor 2 sec. after IG switch ON to OFFBelow 3.0VSV2 (B39) - E1 (B69)G-Y e BRIdling9 - 14
VSV3 (B38) - E1 (B69)B-Y e BRIdling9 - 14
VSV4 (B60) - E1 (B69)L-W e BR
Idling and other shift position ºPº or ºNº position (for A/T).
Idling (for M/T)Below 3.0VSV4 (B60) E1 (B69)LW e BR
Idling and shift position ºPº or ºNº position (for A/T)9 - 14
IG switch ON2.3 - 3.0
PIM1 (B62) - E2 (B65)B-Y e W-BIG switch ON and apply vacuum 26.7 kPa
(200 mm Hg, 7.9 in. Hg)1.0 - 1.5
EFI+ (A27) - E2 (B65)B e W-BIG switch ONPulse generation
(See page DI-285)
EFI- (A26) - E2 (B65)W e W-BIG switch ONPulse generation
(See page DI-285)

DI-168
- DIAGNOSTICSENGINE (2JZ-GTE)
396 Author
: Date
:
1997 SUPRA (RM502U) ETC+ (A14) - E2 (B65)
Y e W-BIG switch ONPulse generation
(See page DI-285)
ETC- (A13) - E2 (B65)BR e W-BIG switch ONPulse generation
(See page DI-285)

DI4SL-01
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-169
397 Author
: Date
:
1997 SUPRA (RM502U)
PROBLEM SYMPTOMS TABLE
When the malfunction code is not confirmed in the DTC check and the problem still can not be confirmed
in the basic inspection, then proceed to this step and perform troubleshooting according to the numbered
order given in the table below.
SymptomSuspect AreaSee page
Does not start (Engine does not crank)1. Starter and Starter relayST-14, ST-16
Does not start (No initial combustion)
1. ECM power source circuit
2. Fuel pump control circuit
3. Engine control module (ECM)DI-304
DI-248
IN-18
Does not start (No complete combustion)1. Fuel pump control circuitDI-248
Difficult to start (Engine cranks normally)
1. Starter signal circuit
2. Fuel pump control circuit
3. CompressionDI-301
DI-248
EM-3
Difficult to start (Cold engine)1. Starter signal circuit
2.Fuel pump control circuitDI-301
DI-248
Difficult to start (Hot engine)
1. Starter signal circuit
2. Fuel pressure control circuit
3. Fuel pump control circuitDI-301
DI-309
DI-248
Poor idling (High engine idle speed)1. A/C signal circuit
2. ECM power source circuitDI-722
DI-304
Poor idling (Low engine idle speed)1. A/C signal circuit
2. Fuel pump control circuitDI-722
DI-248
Poor idling (Rough idling)1. Compression
2. Fuel pump control circuitEM-3
DI-248
Poor idling (Hunting)1. ECM power source circuit
2. Fuel pump control circuitDI-304
DI-248
Poor Driveability (Hesitation/Poor acceleration)1. Fuel pump control circuit
2. A/T faultyDI-248
DI-391
Poor Driveability (Surging)1. Fuel pump control circuitDI-248
Engine stall (Soon after starting)1. Fuel pump control circuitDI-248
Engine stall (During A/C operation)1. A/C signal circuit
2. Engine control module (ECM)DI-722
IN-18

DI4SM-01
A00152
B+
Power Transistor
Thermistor
Platinum Hot Wire
Output
Voltage
B A
ThermistorPlatinum Hot
Wire
DI-170
- DIAGNOSTICSENGINE (2JZ-GTE)
398 Author
: Date
:
1997 SUPRA (RM502U)
CIRCUIT INSPECTION
DTC P0100 Mass Air Flow Circuit Malfunction
CIRCUIT DESCRIPTION
The mass air flow meter uses a platinum hot wire. The hot wire air flow meter consists of a platinum hot wire,
thermistor and a control circuit installed in a plastic housing. The hot wire air flow meter works on the principle
that the hot wire and thermistor located in the intake air bypass of the housing detect any changes in the
intake air temperature.
The hot wire is maintained at the set temperature by controlling the current flow through the hot wire. This
current flow is then measured as the output voltage of the air flow meter.
The circuit is constructed so that the platinum hot wire and thermistor provide a bridge circuit, with the power
transistor controlled so that the potential of ºAº and ºBº remains equal to maintain the set temperature.
DTC No.DTC Detecting ConditionTrouble Area
Open or short in mass air flow meter circuit with engine speed
4,000 rpm or less

Open or short in mass air flow meter circuit
P0100Open or short in mass air flow meter circuit with engine speed
4,000 rpm or more
(2 trip detection logic)

Oen or short in mass air flow meter circuit

Mass air flow meter

ECM
If the ECM detects DTC ºP0100º it operates the fail safe function, keeping the ignition timing and injection
volume constant and making it possible to drive the vehicle.
HINT:
After confirming DTC P0100 use the OBD II scan tool or TOYOTA hand-held tester to confirm the mass air
flow ration from ºCURRENT DATAº.
Mass Air Flow Value (gm / sec.)Malfunction
0.0
Mass Air flow meter power source open

VG circuit open or short
359.0 or more
VG - circuit open

FI6930
B-W
R/B No.22
2A
EFI No.1 B
BatteryEFI Main RelayB-R R/B No.2
B-Y
W-B
EBEA2
2
22
2 23
5
1
EA1
8
5
1
Mass Air Flow Meter2
5Y-R
B-RA
B
B 66
28
E2G
E1 VG GR24
M-RELB+ ECM
1
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-171
399 Author
: Date
:
1997 SUPRA (RM502U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Connect the OBD II scan tool or TOYOTA hand-held tester, and read value of
mass air flow rate.
RESULT:
(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.
(c) Start the engine.
CHECK:
Read mass air flow rate on the OBD II scan tool or TOYOTA hand-held tester.
RESULT:
Type IType II
Mass air flow rate0.0 gm / sec.359.0 gm / sec. or more
Type I Go to step 2.
Type II Go to step 5.

BE6653
P24310A00099
ON
1(+)
A00689
STARTCheck Harness A
ECM
B66 VG(+)
DI-172
- DIAGNOSTICSENGINE (2JZ-GTE)
400 Author
: Date
:
1997 SUPRA (RM502U)
2 Check voltage of mass air flow meter power source.
PREPARATION:
(a) Disconnect the mass air flow meter connector.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminal 1 of mass air flow meter con-
nector and body ground.
OK:
Voltage: 9 - 14 V
NG Check for open in harness and connector be-
tween EFI main relay (Marking: EFI MAIN) and
mass air flow meter (See page IN-28).
OK
3 Check voltage between terminal VG of ECM and body ground.
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Start the engine.
CHECK:
Measure voltage between terminal VG of ECM and body
ground while engine is idling, transmission is in park or neutral
position and A/C switch is OFF.
OK:
Voltage: 1.1 - 1.5 V
OK Check and replace ECM (See page IN-28).
NG

S00344
Check Harness A
ECM
B28 E2G
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-173
401 Author
: Date
:
1997 SUPRA (RM502U)
4 Check for open and short in harness and connector between mass air flow meter
and ECM (See page IN-28).
NG Repair or replace harness or connector.
OK
Replace mass air flow meter.
5 Check continuity between terminal E2G of ECM and body ground.
PREPARATION:
Connect Check Harness A (See page DI-164).
CHECK:
Check continuity between terminal E2G of ECM and body
ground.
OK:
Continuity (1 W or less)
NG Check and replace ECM (See page IN-28).
OK
6 Check for open in harness and connector between mass air flow meter and ECM
(See page IN-28).
NG Repair or replace harness or connector.
OK
Replace mass air flow meter.

DI-174
- DIAGNOSTICSENGINE (2JZ-GTE)
402 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0101 Mass Air Flow Circuit Range / Performance
Problem
CIRCUIT DESCRIPTION
Refer to ºMass Air Flow Circuit Malfunctionº on page DI-170.
DTC No.DTC Detecting ConditionTrouble Area
P0101
Conditions (a), (b) and (c) continue with engine speed 900
rpm or less:
(2 trip detection logic)
(a) Closed throttle position switch: ON
(b) Mass air flow meter output > 2.2 V
(c) Engien coolant temp.
70°C

Mass air flow meterP0101
Conditions (a) and (b) continue with engine speed 1,500 rpm or
more:
(2 trip detection logic)
(a) Mass air flow meter output < 1.0 V
(b) VTA
0.72 V

Mass air flow meter
WIRING DIAGRAM
Refer to page DI-170 or the WARNING DIAGRAM.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0101) being output?
YES Go to relevant DTC chart.
NO
Replace mass air flow meter.
DI4SN-01

FI4741
Acceptable
Resistance kW
-20 0
20 40 60 80 100
(-4) (32) (68)(104)(140)(176)(212)
Temperature °C (°F) 0.1 0.20.3 0.51 2 35 10 2030
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-175
403 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temperature sensor is built into the air flow meter
and senses the intake air temperature.
A thermistor built in the sensor changes the resistance value
according to the intake air temperature.
The lower the intake air temperature, the greater the thermistor
resistance value, and the higher the intake air temperature, the
lower the thermistor resistance value (See Fig. 1).
The intake air temperature sensor is connected to the ECM.
The 5 V power source voltage in the ECM is applied to the in-
take air temperature sensor from the terminal THA via a resistor
R.
That is , the resistor R and the intake air temperature sensor are
connected in series. When the resistance value of the intake air
temperature sensor changes in accordance with changes in the
intake air temperature, the potential at terminal THA also
changes. Based on this signal, the ECM increases the fuel in-
jection volume to improve driveability during cold engine opera-
tion.
If the ECM detects the DTC ºP0110º, it operates the fail safe
function in which the intake air temperature is assumed to be
20°C (68°F).
<Reference>
Intake Air Temp. °C (°F)Resistance (kW)Voltage (V)
-20 (-4)16.24.3
0 (32)5.93.4
20 (68)2.52.4
40 (104)1.11.4
60 (140)0.60.9
80 (176)0.30.5
100 (212)0.10.2
DTC No.DTC Detecting ConditionTrouble Area
P0110Open or short in intake air temp. sensor circuit

Open or short in intake air temp. sensor circuit

Intake air temp. sensor

ECM
HINT:
After confirming DTC P0110 use the OBD II scan tool or TOYOTA hand-held tester to confirm the intake
air temperature from ºCURRENT DATAº.
Temperature DisplayedMalfunction
- 40°C (- 40°F)Open circuit
140°C (284°F) or moreShort circuit
DI4SO-01