1998 TOYOTA LAND CRUISER display

- DIAGNOSTICSENGINE
DI-67
260 Author
: Date
:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help deter-
mine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean
or rich, and other data from the time the malfunction occurred.
1 Are there any other codes (besides DTC P0101) being output?
PREPARATION:
(a) Connect the hand-held tester or the OBD II scan tool to DLC3.
(b) Turn the ignition switch ON and push the hand-held tester or OBD II scan tool main switch ON.
(c) When using hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / CURRENT CODES.
CHECK:
Read the DTC using the hand-held tester or the OBD ll scan tool.
RESULT:
Display (DTC output)Proceed to
ºP0101º and other DTCsA
Only P0101B
HINT:
If any other codes besides P0101 are output, perform the troubleshooting for those codes first.
B Replace mass air flow meter.
A
Go to relevant DTC chart (See page DI-36).

- 20 0 20 40 60 80 100
(- 4) 32 68 104 140 176 212 30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
A21047
Acceptable (Fig.1)
Resistance KW
Temp. C (F)
DI-68
- DIAGNOSTICSENGINE
261 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P0110 Intake Air Temperature Circuit
DTC P0112 Intake Air Temperature Circuit Low Input
DTC P0113 Intake Air Temperature Circuit High Input
CIRCUIT DESCRIPTION
The intake air temperature (IAT) sensor, mounted on the mass
air flow (MAF) meter, monitors the intake air temperature. The
IAT sensor has a thermistor that varies its resistance depending
on the temperature of the intake air. When the air temperature
is low, the resistance in the thermistor increases. When the tem-
perature is high, the resistance drops. The variations in resis-
tance are reflected as voltage changes to the ECM terminal.
(See Fig. 1).
The intake air temperature sensor is connected to the ECM
(See below ). The 5 V power source voltage in the ECM is ap-
plied to the intake air temperature sensor from terminal THA
(THAR) via 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 voltage at terminal THA (THAR) also
changes. Based on this signal, the ECM increases the fuel in-
jection volume to improve the driveability during cold engine op-
eration.
DTC No.Proceed toDTC Detection ConditionTrouble Area
P0110Step 1
Open or short in intake air
temperature sensor circuit for
0.5 sec.

Open or short in intake air temperature sensor circuit
P0112Step 4Short in intake air tempera-
ture sensor circuit for 0.5 sec.

Open or short in intake air temperature sensor circuit

Intake air temperature sensor (built in mass air flow meter)

ECM
P0113Step 2Open in intake air tempera-
ture sensor circuit for 0.5 sec.
ECM
HINT:
After confirming DTC ºP0110, P0112 or P0113º, use the hand-held tester or the OBD II scan tool to confirm
the intake air temperature in the ºDIAGNOSIS / ENHANCED OBD II / DATA LIST / ALLº.
Temperature DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
DI1LE-13

- DIAGNOSTICSENGINE
DI-71
264 Author
: Date
:
2004 LAND CRUISER (RM1071U)
1 Connect OBD II scan tool or hand-held tester, and read value of intake air tem-
perature.
PREPARATION:
(a) Connect the OBD II scan tool or the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or the hand-held tester main switch ON.
(c) When using hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / INTAKE AIR.
CHECK:
Read the temperature value on the OBD II scan tool or the hand-held tester.
OK:
Same as actual intake air temperature.
RESULT:
Temperature DisplayedProceed to
-40°C (-40°F)A
140°C (284°F) or moreB
OK (Same as present temperature)C
HINT:

If there is an open circuit, the OBD II scan tool or the hand-held tester indicates -40°C (-40°F).

If there is a short circuit, the OBD II scan tool or the hand-held tester indicates 140°C (284°F) or more.
B Go to step 4.
C Check for intermittent problems
(See page DI-3).
A

- DIAGNOSTICSENGINE
DI-75
268 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P0115 Engine Coolant Temperature Circuit
DTC P0117 Engine Coolant Temperature Circuit Low
Input
DTC P0118 Engine Coolant Temperature Circuit High
Input
CIRCUIT DESCRIPTION
A thermistor is built in the Engine Coolant Temperature (ECT) sensor and changes the resistance value ac-
cording to the engine coolant temperature.
The structure of the sensor and connection to the ECM is the same the Intake Air Temperature (IAT) sensor.
HINT:
If the ECM detects the DTC ºP0115, P0117 or P0118º, it operates the fail-safe function in which the ECT
is assumed to be 80 C (176 F).
DTC No.Proceed toDTC Detection ConditionTrouble Area
P0115Step 1
Open or short in engine cool-
ant temperature sensor circuit
for 0.5 sec.
P0117Step 4
Short in engine coolant tem-
perature sensor circuit for 0.5
sec.
Open or short in engine coolant temperature sensor circuit

Engine coolant temperature sensor

ECM
P0118Step 2
Open in engine coolant tem-
perature sensor circuit for 0.5
sec.
HINT:
After confirming DTC ºP0115, P0117 or P0118,º use the OBD II scan tool or the hand-held tester to confirm
the engine coolant temperature from the DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL.
Temperature DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
MONITOR DESCRIPTION
The ECT (Engine Coolant Temperature) sensor is used to monitor the engine coolant temperature. The ECT
sensor has a thermistor that varies its resistance depending on the temperature of the engine coolant. When
the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the
resistance drops. The variations in resistance are reflected in the voltage output from the sensor.
The ECM monitors the sensor voltage and uses this value to calculate the engine coolant temperature.
When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault
in the ECT sensor and sets a DTC.
Example:
When the ECM calculates that the ECT is less than -40C (-40F), or more than 140C (284F), and if either
the condition continues for 0.5 sec. or more, the ECM will set a DTC.
DI1LF-13

DI-78
- DIAGNOSTICSENGINE
271 Author
: Date
:
2004 LAND CRUISER (RM1071U)
1 Connect OBD II scan tool or hand-held tester, and read value of engine coolant
temperature.
PREPARATION:
(a) Connect the OBD II scan tool or the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or hand-held tester main switch ON.
(c) When using hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / COOLANT TEMP.
CHECK:
Read the temperature value on the OBD II scan tool or the hand-held tester.
OK:
Same value as actual engine coolant temperature.
RESULT:
Temperature DisplayedProceed to
-40°C (-40°F)A
140°C (284°F) or moreB
OK (Same as present temperature)C
HINT:

If there is an open circuit, OBD II scan tool or hand-held tester indicates -40°C (-40°F).

If there is a short circuit, OBD II scan tool or hand-held tester indicates 140°C (284°F) or more.
B Go to step 4.
C Check for intermittent problems
(See page DI-3).
A

DI-86
- DIAGNOSTICSENGINE
279 Author
: Date
:
2004 LAND CRUISER (RM1071U)DTC No.
DTC Detection Condition
Condition (a) of DTC P0120, P0122, P0123, P0220, P0222 or P0223 continues
for 2 sec.
(Open or short in the throttle control motor and sensor circuit)Trouble Area
P0120
Detection conditions for DTCs P0122 and P0123 are not satis-
fied but condition (a) is satisfied
(a) VTA1 is º0.2 V or lessº or VTA1 is º4.8 V or moreº
Throttle control motor and sensor

ECM
P0122(a) VTA1 is 0.2 V or less

Throttle control motor and sensor

Short in VTA1 circuit

Open in VC circuit

ECM
P0123(a) VTA1 is 4.8 V or more

Throttle control motor and sensor

Open in VTA1 circuit

Open in E2 circuit

VC and VTA1 circuit are short-circuited

ECM
P0220
Detection conditions for DTCs P0222 and P0223 are not satis-
fied but condition (a) is satisfied
(a) VTA2 is º0.5 V or lessº or VTA2 is º4.8 V or moreº and
VTA1 is º0.2 V or moreº and VTA1 is º1.8 V or lessº

Throttle control motor and sensor

ECM
P0222(a) VTA2 is 0.5 V or less

Throttle control motor and sensor

Short in VTA2 circuit

Open in VC circuit

ECM
P0223(a) VTA2 is º4.8 V or moreº and
VTA1 is º0.2 V or moreº and VTA1 is º1.8 V or lessº

Throttle control motor and sensor

Open in VTA2 circuit

Open in E2 circuit

VC and VTA2 circuit are short-circuited

ECM
P2135
Condition (a) continues for 0.5 sec. or more, or
condition (b) continues for 0.4 sec. or more:
(a) Difference between VTA1 and VTA2 is 0.02 V or less
(b) VTA1 is º0.2 V or lessº and VTA2 is º0.5 V or lessº
VTA1 and VTA2 circuit are short-circuited

Throttle control motor and sensor

ECM
HINT:

After confirming DTCs, use the hand-held tester or the OBD II scan tool to confirm the throttle valve
opening percentage and closed throttle position switch condition.

THROTTLE POS means VTA1 signal as well as the THROTTLE POS #2 for the VTA2 signal.
Reference (Normal condition):
Tester displayAccelerator pedal fully releasedAccelerator pedal fully depressed
THROTTLE POS10 to 24 %66 to 98%
THROTTLE POS #22.1 to 3.1 V4.5 to 5.5 V

DI-90
- DIAGNOSTICSENGINE
283 Author
: Date
:
2004 LAND CRUISER (RM1071U)
Hand-held tester:
1 Connect hand-held tester, and read the voltage for throttle position sensor data.
PREPARATION:
(a) Connect the hand-held tester or the OBD II scan tool to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester or OBD II scan tool main switch ON.
(c) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / THROTTLE POS
and THROTTLE POS #2.
CHECK:
Read voltage value displayed on the hand-held tester.
OK:
RESULT:
Throttle position expressed as percentage and voltage
Accelerator pedal releasedAccelerator pedal depressedTrouble areaProceed toTHROTTLE POS
(VTA1)THROTTLE POS #2
(VTA2)THROTTLE POS
(VTA1)THROTTLE POS #2
(VTA2)Trouble areaProceed to
0 %0 to 0.2 V0 %0 to 0.2 VVC circuit open
100 %4.5 to 5.5 V100 %4.5 to 5.5 VE2 circuit open
0 % or 100 %2.1 to 3.1 V
(Fail safe)0 % or 100 %2.1 to 3.1 V
(Fail safe)VTA1 circuit open or
ground shortA
about 16 %
(Fail safe)0 to 0.2 or 4.5 to 5.5 Vabout 16 %
(Fail safe)0 to 0.2 or 4.5 to 5.5 VVTA2 circuit open or
ground short
10 to 24 %2.15 to 3.05 V64 to 96 %
(Does not fail safe)4.5 to 5.5 V
(Does not fail safe)Throttle position sen-
sor circuit is normalB
B Go to step 5.
A

- DIAGNOSTICSENGINE
DI-93
286 Author
: Date
:
2004 LAND CRUISER (RM1071U)
5 Check if DTC output recur.
PREPARATION:
(a) Clear the DTC (See page DI-3).
(b) Start the engine.
(c) Run the engine at idle for 15 seconds or more.
CHECK:
Read the DTC (See page DI-3).
RESULT:
Display (DTC Output)Proceed to
ºP0120, P0122, P0123, P0220, P0222, P0223 and/or P2135º are output
againA
No DTC outputB
B System is OK.
A
Replace ECM (See page SF-60).