1986 TOYOTA LAND CRUISER ignition

A19548
Engine Coolant
Temp. Sensor
ECM
E2 THW
E2 THW
E2
E5
ECM Connector
A19550
Engine Coolant
Temp. Sensor
ECM
2
1
E2 THW E2
DI-80
- DIAGNOSTICSENGINE
273 Author
: Date
:
2004 LAND CRUISER (RM1071U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the E2 engine coolant temperature sensor
connector.
(b) Connect terminals THW and E2 of the E5 ECM connector.
HINT:
Before checking, do a visual and contact pressure checks for
the ECM connector.
(c) Turn the ignition switch ON.
(d) 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:
Temperature value: 1405C (2845F) or more
OK Repair or replace harness or connector.
NG
Confirm good connection at ECM. If OK,
check and replace ECM (See page SF-60).
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the E2 engine coolant temperature sensor
connector.
(b) Turn the ignition 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:
Temperature value: -405C (-405F)
OK Replace engine coolant temperature sensor.
NG

A19551A19635
ECM Engine Coolant
Temp. Sensor
E2 THW
E5
ECM Connector
- DIAGNOSTICSENGINE
DI-81
274 Author
: Date
:
2004 LAND CRUISER (RM1071U)
5 Check for short in harness or ECM.
PREPARATION:
(a) Disconnect the E5 ECM connector.
(b) Turn the ignition 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:
Temperature value: -405C (-405F)
OK Repair or replace harness or connector.
NG
Replace ECM (See page SF-60).

- DIAGNOSTICSENGINE
DI-87
280 Author
: Date
:
2004 LAND CRUISER (RM1071U)
MONITOR DESCRIPTION
The ECM uses throttle position sensor to monitor the throttle valve opening angle.
(a) There is a specific voltage difference expected between VTA1 and VTA2 for each throttle opening
angle.

If the difference between VTA1 and VTA2 is incorrect the ECM interprets this as a fault and will set a
DTC.
(b) VTA1 and VTA2 each have a specific voltage operating range.

If VTA1 or VTA2 is out of the normal operating range the ECM interprets this as a fault and will set a
DTC.
(c) VTA1 and VTA2 should never be close to the same voltage levels.

If VTA1 is within 0.02 V of VTA2 the ECM interprets this as a short circuit in the throttle position sensor
system and will set a DTC.
FAIL SAFE
If the ETCS (Electronic Throttle Control System) has a malfunction, the ECM cuts off current to the throttle
control motor. The throttle control valve returns to a predetermined opening angle (approximately 16°) by
the force of the return spring. The ECM then adjusts the engine output by controlling the fuel infection (inter-
mittent fuel-cut) and ignition timing in accordance with the accelerator pedal opening angle to enable the
vehicle to continue at a minimum speed.
If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven slowly.
If a ºpassº condition is detected and then the ignition switch is turned OFF, the fail-safe operation will stop
and the system will return to normal condition.
MONITOR STRATEGY
P0120Throttle position sensor (sensor 1) range check
(Fluttering)
P0122Throttle position sensor (sensor 1) range check
(Low voltage)
P0123Throttle position sensor (sensor 1) range check
(High voltage)
Related DTCsP0220Throttle position sensor (sensor 2) range check
(Fluttering)
P0222Throttle position sensor (sensor 2) range check
(Low voltage)
P0223Throttle position sensor (sensor 2) range check
(High voltage)
P2135Throttle position sensor range check (Correla-
tion)
Required sensors/componentsThrottle position sensor
Frequency of operationContinuous
Duration2 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever the follow-
ing DTCs are not presentSee ºList of disable a monitorº (on page DI-3).
Throttle control motor powerON

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

A21022
Throttle Body Connector
VC VTA2VTA
E2
T16
Front View Wire Harness Side:
A21038
E2 (-) VC (+)E5ECM Connector
DI-92
- DIAGNOSTICSENGINE
285 Author
: Date
:
2004 LAND CRUISER (RM1071U)
3 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Disconnect the T16 throttle control motor and sensor con-
nector.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between the specified terminals of the E5
ECM connector.
OK:
Tester ConnectionSpecified Condition
VC (E5-18) - E2 (E5-28)4.5 to 5.5 V
NG Replace ECM (See page SF-60).
OK
4 Replace throttle body (See page SF-36).
Go

A21022
Throttle Body Connector
VC VTA2VTA
E2
T16
Front View Wire Harness Side:
A21038
E2 (-) VC (+)E5ECM Connector
- DIAGNOSTICSENGINE
DI-95
288 Author
: Date
:
2004 LAND CRUISER (RM1071U)
2 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Disconnect the T16 throttle control motor and sensor con-
nector.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between the specified terminals of the E5
ECM connector.
OK:
Tester ConnectionSpecified Condition
VC (E5-18) - E2 (E5-28)4.5 to 5.5 V
NG Replace ECM (See page SF-60).
OK
3 Replace throttle body (See page SF-36).
Go

- DIAGNOSTICSENGINE
DI-97
290 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P0121 Throttle/Pedal Position Sensor/Switch ºAº
Circuit Range/Performance Problem
HINT:
This is the purpose of the ºthrottle position sensorº.
CIRCUIT DESCRIPTION
Refer to DTC P0120 on page DI-84.
DTC No.DTC Detecting ConditionTrouble Area
P0121
Condition (a) continues for 2.0 sec.:
(a) Difference between VTA1 and VTA2 deviates from the
threshold
Throttle control motor and sensor
MONITOR DESCRIPTION
The ECM uses throttle position sensor to monitor the throttle valve opening angle.
This sensor including two signals, VTA1 and VTA2. VTA1 is used to detect the throttle opening angle and
VTA2 is used to detect malfunctions in VTA1. There are several checks that the ECM performs confirm prop-
er operation of the throttle position sensor and VTA1.
There is a specific voltage difference expected between VTA1 and VTA2 for each throttle opening angle.
If the voltage output difference of the VTA1 and VTA2 deviates from the normal operating range, the ECM
interprets this as a malfunction of the throttle position sensor. The ECM will turn on the MIL and a DTC is
set.
FAIL SAFE
If the ETCS (Electronic Throttle Control System) has a malfunction, the ECM cuts off current to the throttle
control motor. The throttle control valve returns to a predetermined opening angle (approximately 16°) by
the force of the return spring. The ECM then adjusts the engine output by controlling the fuel infection (inter-
mittent fuel-cut) and ignition timing in accordance with the accelerator pedal opening angle to enable the
vehicle to continue at a minimum speed.
If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven slowly.
If a ºpassº condition is detected and then the ignition switch is turned OFF, the fail-safe operation will stop
and the system will return to normal condition.
MONITOR STRATEGY
Related DTCsP0121Throttle position sensor rationality
Required sensors/componentsThrottle position sensor
Frequency of operationContinuous
Duration2 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever the follow-
ing DTCs are not presentSee ºList of disable a monitorº (on page DI-3).
VTA2 voltage-4.6 V
DI1LI-19

DI-100
- DIAGNOSTICSENGINE
293 Author
: Date
:
2004 LAND CRUISER (RM1071U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever the follow-
ing DTCs are not presentSee ºList of Disable a Monitorº table (on page DI-3)
Fuel cutOFF
EngineRunning
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Time until ºengine coolant temperatureº detection temperature reaches feedback start temperature
When the temperature at the time of engine starting is
10°C (50°F) or moreEngine coolant temperature is less than ºclosed-loop enable temperatureº
when 2 min. or more after engine start
When the temperature at the time of engine starting is
º-6.6°C (20°F)º to º10°C (50°F)ºEngine coolant temperature is less than ºclosed-loop enable temperatureº
when 5 min. or more after engine start
When the temperature at the time of engine starting is
-6.6°C (20°F) or lessEngine coolant temperature is less than ºclosed-loop enable temperatureº
when 20 min. or more after engine start
INSPECTION PROCEDURE
HINT:

If DTC P0115, P0116, P0117, P0118 and P0125 are output simultaneously, engine coolant tempera-
ture sensor circuit may be open or short. Perform the troubleshooting of DTC P0115, P0117 or P0118
first.

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 determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel
ratio was lean or rich, as well as other data from the time when a malfunction occurred.
1 Are there any other codes (besides DTC P0125) being output?
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) When using hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / CURRENT CODES.
CHECK:
Read the DTCs using the hand-held tester or the OBD II scan tool.
RESULT:
Display (DTC output)Proceed to
P0125A
ºP0125º and other DTCsB
HINT:
If any other codes besides ºP0125º are output, perform the troubleshooting for those DTCs first.
B Go to relevant DTC chart (See page DI-36).
A