1998 TOYOTA LAND CRUISER ECO mode

- DIAGNOSTICSENGINE
DI-331
524 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P2121 Throttle/Pedal Position Sensor/Switch ºDº
Circuit Range/Performance
HINT:
This is repair procedure for the ºaccelerator pedal position sensorº.
CIRCUIT DESCRIPTION
Refer to DTC P2120 on page DI-318.
DTC No.DTC Detecting ConditionTrouble Area
P2121
Conditions (a) and (b) continue for 0.5 seconds:
(a) Difference between VPA and VPA2 exceeds the threshold
(b) IDL is OFF
Accelerator pedal position sensor circuit

Accelerator pedal position sensor

ECM
MONITOR DESCRIPTION
The accelerator pedal position sensor is mounted on the accelerator pedal bracket. The accelerator pedal
position sensor has 2 sensor elements/signal outputs: VPA1 and VPA2. VPA1 is used to detect the actual
accelerator pedal angle (used for engine control) and VPA2 is used to detect malfunctions in VPA1. When
the difference between the voltage outputs of VPA1 and VPA2 deviate from the standard, the ECM con-
cludes the accelerator pedal position sensor has a malfunction. The ECM turns on the MIL and a DTC is
set.
FAIL SAFE
The accelerator pedal position sensor has two (main and sub) sensor circuits. If a malfunction occurs in ei-
ther of the sensor circuits, the ECM detects the abnormal signal voltage difference between the two sensor
circuits and switches to limp mode. In limp mode, the remaining circuit is used to calculate the accelerator
pedal opening to allow the vehicle to continue driving.
If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal to be fully closed.
In this case, the throttle valve will remain closed as if the engine is idling.
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 DTCsP2121Accelerator position sensor (rationality)
Required sensors/componentsAccelerator position sensor
Frequency of operationContinuous
Duration0.5 sec.
MIL operationImmediate
Sequence of operationNone
DIC2T-01

FI7052DepressedReleased
DI-332
- DIAGNOSTICSENGINE
525 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 (on page DI-3)
Either of the following conditions is metA or B
A. Ignition switchON
B. Throttle control motor powerON
System is not under limp home mode due to accelerator pedal position sensor malfunction
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
|VPA - (VPA2 - 0.8)|*
*Corrected by learning valueMore than 0.4 V
WIRING DIAGRAM
Refer to DTC P2120 on page DI-318.
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, as well as other data from the time when a malfunction occurred.
Hand-held tester:
1 Connect hand-held tester, and read the voltage for accelerator pedal position
sensor data.
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tes-
ter main switch ON.
(c) Enter the following menus: DIAGNOSIS / ENHANCED
OBD II / DATA LIST / ETCS / ACCEL POS #1 and ACCEL
POS #2.
CHECK:
Read the voltage for the accelerator pedal position sensor data.
OK:
Accelerator pedalACCEL POS #1ACCEL POS #2
Released0.5 to 1.1 V1.2 to 2.0 V
Depressed2.6 to 4.5 V3.4 to 5.3 V
OK Replace ECM (See page SF-60).
NG

DI079-18
ENGINE CONTROL SYSTEM Check Sheet
Customer's Name
Driver's Name
Data Vehicle
Brought in
Engine model
VIN
Production Date
Licence Plate No.
Odometer Reading
Problem Symptoms
Engine does
not Start
Difficult to
Start
Poor Idling
Poor
Driveability
Engine Stall
Others
Engine does not crankNo initial combustionNo complete combustion
Engine cranks slowly
Other
Incorrect first idleIdling rpm is abnormalHigh ( rpm)Low ( rpm)
Rough idling
Other
HesitationBack fireMuffler explosion (after-fire)Surging
Knocking
Other
Soon after startingAfter accelerator pedal depressed
After accelerator pedal released
During A/C operation
Shifting from N to D
Other
Dates Problem
Occurred
Problem Frequency
Condition When
Problem Occurs
Weather
Engine Operation
Engine Temp. Place Outdoor
TemperatureConstant
Sometimes ( times per day/month)Once only
Other
Fine
CloudyRainySnowyVarious/Other
Hot
Warm CoolCold (approx. °C/ °F)
Highway
SuburbsInner cityUphillDownhill
Rough road
Other
Cold
Warming upAfter warming upAny temp.Other
Starting
Just after starting ( min.)IdlingRacing
Driving
Constant speedAccelerationDeceleration
A/C switch ON/OFF
Other
Condition of malfunction indicator lightRemains on Sometimes light up Does not light up
NormalMalfunction code(s) (code )
Freezed frame data ( )
NormalMalfunction code(s) (code )
Freezed frame data ( )
Normal Mode
(Pre-check)
Check Mode DTC InspectionInspector's
Name
km
miles
(MIL)
DI-2
- DIAGNOSTICSENGINE
195 Author
: Date
:
2004 LAND CRUISER (RM1071U)
CUSTOMER PROBLEM ANALYSIS CHECK

DI078-23
Vehicle Brought to Workshop
Customer Problem Analysis P. DI-2
Problem Symptom Confirmation
If the engine does not start perform steps 10 and 12 firstConnect the OBD II scan tool or hand-held tester to DLC3 P. DI-3
If the display indicates a communication fault in the tool, inspect DLC3 P. DI-3
Check DTC and Freeze Frame Data (Precheck)
Record or Print DTC and Freeze Frame Data P. DI-3
Clear DTC and Freeze Frame Data P. DI-3
Visual Inspection
Setting the Check Mode Diagnosis P. DI-3
Symptom Simulation P. IN-26
Basic Inspection P. DI-3DTC Chart P. DI-36
Problem Symptoms Table P. DI-48
Circuit Inspection P. DI-49
Adjustment, Repair
DTC Check P. DI-3
Items insideare titles of pages in
in the bottom portion. See the indicated
pages for detailed explanations. this manual, with the page number
Malfunction
occurs.Malfunction does not occur.
Parts Inspection
Check for Intermittent Problems P. DI-3
Identification of Problem
Confirmation Test
End 1
2
3
4
5
6
7
108
9
11
12
13
15 14
16
Normal Malfunction code.
17The hand-held tester can be used at
bold frame.
- DIAGNOSTICSENGINE
DI-1
194 Author
: Date
:
2004 LAND CRUISER (RM1071U)
ENGINE
HOW TO PROCEED WITH TROUBLESHOOTING
Troubleshoot in accordance with the procedure on the following page.

DI-4
- DIAGNOSTICSENGINE
197 Author
: Date
:

The diagnosis system operates in ºnormal modeº
during normal vehicle use. In ºnormal modeº, 2 trip
detection logic* is used to ensure accurate detec-
tion of malfunctions. A ºcheck modeº is also avail-
able to technicians as an option. In ºcheck modeº,
1 trip detection logic is used for simulating malfunc-
tion symptoms and increasing the system's ability to
detect malfunctions, including intermittent malfunc-
tions (hand-held tester only) (See step 3).

*2 trip detection logic:
When a malfunction is first detected, the malfunc-
tion is temporarily stored in the ECM memory. This
is known as 1st trip detection. If the ignition switch
is turned OFF and then ON again, and the same
malfunction is detected again, the MIL will illumi-
nate. This is known as 2nd trip detection.

Freeze frame data:
The freeze frame data records the engine condi-
tions (fuel system, calculated load, engine coolant
temperature, fuel trim, engine speed, vehicle
speed, etc.) when a malfunction is detected. When
troubleshooting, freeze frame data can help deter-
mining 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.
Priorities for troubleshooting:
When multiple DTCs occur, find out the order in which the DTCs
should be inspected by checking the component's DTC chart.
If no instructions are written in the DTC chart, check DTCs in the
following order of priority:
(1) DTCs other than fuel trim malfunction DTCs
(P0171, P0172, P0174 and P0175) and misfire
DTCs (P0300 to P0308).
(2) Fuel trim malfunction DTCs (P0171, P0172, P0174
and P0175).
(3) Misfire DTCs (P0300 to P0308).

A07061DLC3
Hand-Held Tester
DI-6
- DIAGNOSTICSENGINE
199 Author
: Date
:
2. DTC CHECK (Normal Mode)
NOTICE:

If no DTC appears in normal mode:
On the OBD ll scan tool or the hand-held tester check
the pending fault code using the Continuous Test Re-
sults function (Mode 7 for SAE J1979).

When the diagnosis system is changed from normal
mode to check mode or vice-versa, all DTCs and
freeze frame data recorded in normal mode will be
erased. Before changing modes, always check and
make a note of DTCs and freeze frame data.
(a) Checking DTCs using the OBD II scan tool or hand-held
tester.
(1) Connect the OBD II scan tool or the hand-held tes-
ter to DLC3.
(2) Turn the ignition switch ON.
(3) Use the OBD II scan tool or the hand-held tester to
check the DTCs and freeze frame data and then
write them down.
For the hand-held tester, enter the following me-
nus: DIAGNOSIS / ENHANCED OBD II / DTC INFO
/ CURRENT CODEDS. For the OBD II scan tool,
see its instruction manual.
(4) See page DI-36 to confirm the details of the
DTCs.
NOTICE:
When simulating a symptom with the OBD II scan tool (ex-
cluding hand-held tester) to check the DTCs, use the nor-
mal mode. For DTCs chart subject to º2 trip detection log-
icº, perform either of the following actions.

Check the pending fault code:
For the hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DTC INFO / PEND-
ING CODES.

Turn the ignition switch OFF after the symptom is
simulated once. Then repeat the simulation process
again. When the problem has been simulated twice,
the MIL comes on and the DTCs are recorded in the
ECM.

A07061DLC3
Hand-Held Tester
BR3904
0.13 sec.0.13 sec.
ON
OFF
- DIAGNOSTICSENGINE
DI-7
200 Author
: Date
:

Check the pending fault code using the Continuous
Test Results function (Mode 7 for SAE J1979) on the
OBD II scan tool.
(b) Clearing the DTCs using the OBD II scan tool or the
hand-held tester.
(1) Connect the OBD II scan tool or the hand-held tes-
ter to the DLC3.
(2) Turn the ignition switch ON.
(3) Erase DTCs and freeze frame data with the OBD II
scan tool (complying with SAE J1978) or the hand-
held tester. For the hand-held tester: 1) enter the
following menus: DIAGNOSIS / ENHANCED OBD
II / DTC INFO / CLEAR CODES; and 2) press YES.
For the OBD II scan tool, see its instruction manual.
(c) Clearing the DTCs not using the OBD II scan tool or the
hand-held tester.
Remove the EFI or ECD No. 1 and ETCS fuses from the
engine room J/B for more than 60 seconds, or disconnect
the battery terminal for more than 60 seconds.
After disconnecting the battery terminal, perform the ºINI-
TIALIZE procedure.
3. DTC CHECK (Check Mode)
HINT:
Hand-held tester only:
Check mode has a higher sensitivity to detect malfunctions and
can detect malfunctions that normal mode cannot detect.
Check mode can also detect all the malfunctions that normal
mode can detect.
(a) Follow these steps when preparing to use the hand-held
tester check mode.
(1) Make sure that the items below are true:

Battery positive voltage 11 V or more

Throttle valve fully closed

Transmission in the P or N position

A/C switched OFF
(2) Turn the ignition switch OFF.
(3) Connect the hand-held tester to the DLC3.
(4) Turn the ignition switch ON.
(5) Change the ECM to check mode with the hand-
held tester. Enter the following menus: DIAGNOSIS
/ ENHANCED OBD II / CHECK MODE. Make sure
the MIL flashes as shown in the illustration.
NOTICE:
All DTCs and freeze frame data recorded will be erased if:
1) the hand-held tester is used to change the ECM from
normal mode to check mode or vice-versa; or 2) during
check mode, the ignition switch is turned from ON to ACC
or OFF.

DI-8
- DIAGNOSTICSENGINE
201 Author
: Date
:
(6) Start the engine. The MIL should turn off after the
engine starts.
(7) Simulate the conditions of the malfunction de-
scribed by the customer.
(8) After simulating the malfunction conditions, use the
hand-held tester diagnosis selector to check the
DTC, freeze frame data and other data.
(9) After checking the DTC, inspect the applicable cir-
cuit.
(b) Clearing DTCs using the OBD ll scan tool or the hand-
held tester.
(1) Connect the OBD ll scan tool or the hand-held tes-
ter to the DLC3.
(2) Turn the ignition switch ON.
(3) Erase DTCs and freeze frame data with the OBD II
scan tool (complying with SAE J1978) or the hand-
held tester. For the hand-held tester: 1) enter the
following menus: DIAGNOSIS ENHANCED OBD II
/ DTC INFO / CLEAR CODES; and 2) press YES.
For the OBD II scan tool, see its instruction manual.
(c) Clearing the DTCs without using the OBD ll scan tool or
the hand-held tester.
Remove the EFI or ECD No. 1 and ETCS fuses from the
engine room J/B for more than 60 seconds, or disconnect
the battery terminal for more than 60 seconds.
After disconnecting the battery terminal, perform the ºINI-
TIALIZEº procedure.
4. FAIL-SAFE CHART
If any of the following code is recorded, the ECM enters fail-safe mode.
DTC No.Fail-Safe OperationFail-Safe Deactivation Conditions
P0031
P0032
P0037
P0038
P0051
P0052
P0057
P0058
The heater circuit in which an abnormality is detected is
turned offIgnition switch OFF
P0100
P0102
P0103Ignition timing is calculated from engine speed and throttle
angleºPassº condition detected
P0110
P0112
P0113
Intake air temperature is fixed at 20°C (68°F)ºPassº condition detected
P0115
P0117
P0118
Engine coolant temperature is fixed at 80°C (176°F)ºPassº condition detected