Page 611 of 1807
DI-196
- DIAGNOSTICSENGINE (2JZ-GTE)
424 Author: Date:
1997 SUPRA (RM502U)
DTC P0133 Heated Oxygen Sensor Circuit Slow
Response (Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to ºInsufficient Coolant Temp. for Closed Loop Fuel Controlº on page DI-190.
DTC No.DTC Detecting ConditionTrouble Area
P0133
Response time for the heated oxygen sensor voltage output to
change from rich to lean, or from lean to rich, is 1 sec. or more
during idling after the engine is warmed up
(2trip detection logic)
Heated oxygen sensor
HINT:
Bank 1 refers to the bank that includes cylinder No.1.
Sensor 1 refers to the sensor closer to the engine body.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0133) being output?
YES Go to relevant DTC chart.
NO
Replace heated oxygen sensor.
DI4SV-01
Page 612 of 1807
BE6653S02437A03033
ON
Check Harness A
B72, 71
HT1(+) HTS(+)
ECM
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-197
425 Author: Date:
1997 SUPRA (RM502U)
DTC P0135 Heated Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 1)
DTC P0141 Heated Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to ºInsufficient Coolant Temp. for Closed Loop Fuel Controlº on page DI-190.
DTC No.DTC Detecting ConditionTrouble Area
P0135
When the heater operates, heater current exceeds 2 A
(2 trip detection logic)Open or short in heater circuit of heated oxygen sensor
Htd htP0135
P0141Heater current of 0.25 A or less when the heater operates
(2 trip detection logic)Heated oxygen sensor heater
ECM
HINT:
Bank 1 refers to the bank that includes cylinder No.1.
Sensor 1 refers to the sensor closer to the engine body.
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to page DI-190 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Check voltage between terminals HT1, HTS 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 terminals HT1, HTS of ECM connec-
tor and body ground.
HINT:
Connect terminal HT1 to bank 1 sensor 1.
Connect terminal HTS to bank 1 sensor 2.
OK:
Voltage: 9 - 14 V
OK Check and replace ECM (See page IN-28).
NG
DI4SW-01
Page 613 of 1807
DI-198
- DIAGNOSTICSENGINE (2JZ-GTE)
426 Author: Date:
1997 SUPRA (RM502U)
2 Check resistance of heated oxygen sensor heater (See page SF-82).
NG Replace heated oxygen sensor.
OK
Check and repair harness or connector be-
tween EFI main relay (Making: EFI MAIN) and
heated oxygen sensor and ECM.
Page 614 of 1807
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-199
427 Author: Date:
1997 SUPRA (RM502U)
DTC P0136 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to ºInsufficient Coolant Temp. for Closed Loop Fuel Controlº on page DI-190.
DTC No.DTC Detecting ConditionTrouble Area
P0136
Voltage output of the heated oxygen sensor (bank 1 sensor 2)
remains at 0.4 V or more or 0.5 V or less when the vehicle is
driven at 40 km/h (25 mph) or more after the engine is warmed
up
(2 trip detection logic)
Heated oxygen sensor
HINT:
Bank 1 refers to the bank that includes cylinder No.1.
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to page DI-190 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0136) being output?
YES Go to relevant DTC chart.
NO
2 Check for open and short in harness and connector between ECM and heated
oxygen sensor (See page IN-28).
NG Repair or replace harness or connector.
OK
DI4SX-01
Page 615 of 1807
DI-200
- DIAGNOSTICSENGINE (2JZ-GTE)
428 Author: Date:
1997 SUPRA (RM502U)
3 Check the output voltage of heated oxygen sensor (bank 1 sensor 2).
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC 3.
(b) Warm up engine to normal operating temperature.
CHECK:
Read the output voltage of heated oxygen sensor (bank 1 sensor 2) when engine is suddenly raced.
HINT:
Perform quick racing to 4,000 rpm for 3 min. using accelerator pedal.
OK:
Heated oxygen sensor output voltage: Alternates from 0.4 V or less to 0.5 V or more.
OK Check that each connector is properly con-
nected.
NG
Replace heated oxygen sensor
(bank 1 sensor 2).
Page 616 of 1807
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-201
429 Author: Date:
1997 SUPRA (RM502U)
DTC P0171 System too Lean (Fuel Trim)
DTC P0172 System too Rich (Fuel Trim)
CIRCUIT DESCRIPTION
ºFuel trimº refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short-term fuel trim and long-term fuel trim.
ºShort-term fuel trimº is the short-term fuel compensation used to maintain the air-fuel ratio at its ideal
theoretical value. The signal from the heated oxygen sensor indicates whether the air-fuel ratio is RICH or
LEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air-fuel ratio is rich,
and an increase in fuel volume if it is lean.
ºLong-term fuel trimº is overall fuel compensation carried out long-term to compensate for continual devi-
ation of the short-term fuel trim from the central value due to individual engine differences, wear over time
and changes in the usage environment.
If both the short-term fuel trim and long-term fuel trim are LEAN or RICH beyond a certain value, it is de-
tected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When the air fuel ratio feedback is stable after engine warning
up, the fuel trim is considerably in error on the RICH side
(2 trip detection logic)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Heated oxygen sensor malfunction
Mass air flow meter
Engine coolant temp. sensor
P0172
When the air fuel ratio feedback is stable after engine warning
up, the fuel trim is considerably in error on the LEAN side
(2 trip detection logic)
Fuel line pressure
Injector blockage, leak
Heated oxygen sensor malfunction
Mass air flow meter
Engine coolant temp. sensor
HINT:
When DTC P0171 is recorded, the actual air-fuel ratio is on the LEAN side. When DTC P0172 is re-
corded, the actual air-fuel ratio is on the RICH side.
If the vehicle runs out of fuel, the air-fuel ratio is LEAN and DTC P0171 is recorded. The MIL then
comes on.
If the total of the short-term fuel trim value and long-term fuel trim value is within ± 35 %, the system
is functioning normally.
INSPECTION PROCEDURE
1 Check air induction system (See page SF-1).
NG Repair or replace.
OK
DI4SY-01
Page 617 of 1807
DI-202
- DIAGNOSTICSENGINE (2JZ-GTE)
430 Author: Date:
1997 SUPRA (RM502U)
2 Check for heated oxygen sensor data.
PREPARATION:
(a) Connect the OBDII scan tool or TOYOTA hand-held tester to the DLC3.
(b) Warm up engine to normal operating temperature.
CHECK:
Read the heated oxygen sensor output voltage and short-term fuel trim.
HINT:
Read the values for the same bank.
RESULT:
PatternHeated oxygen sensor output voltageShort-term fuel trim
1Lean condition (Changes at 0.55 V or less)Changes at about + 20 %
2Rich condition (Changes at 0.4 V or more)Changes at about - 20 %
3Except 1 and 2
3 Check for heated oxygen sensor
(See page DI-193).
1,2
3 Check fuel pressure (See page SF-5).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page SF-1).
OK
4 Check injector injection (See page SF-25).
NG Replace injector.
OK
Page 618 of 1807
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-203
431 Author: Date:
1997 SUPRA (RM502U)
5 Check mass air flow meter and engine coolant temp. sensor
(See page DI-170, DI-179).
NG Repair or replace.
OK
6 Check for spark and ignition (See page IG-1).
NG Repair or replace.
OK
Check and replace ECU (See page IN-28).
