Engine Control System - Diagnosis: Pre-Check

DIAGNOSTICS SYSTEM

Description
- When troubleshooting On-Board Diagnostic (OBD II) vehicles, the vehicle must be connected to the OBD II scan tool (in compliance with SAE J1978) or the hand-held tester. Various data output from the vehicle's ECM can then be read.
- OBD II regulations require that the vehicle's onboard computer illuminates the Malfunction Indicator Light (MIL) on the instrument panel when the computer detects a malfunction in: 1) the emission control system/components, or 2) the powertrain control components (which affect vehicle emissions), or 3) the computer. In addition, the applicable Diagnostic Trouble Codes (DTCs) prescribed by SAE J2012 are recorded in the ECM memory (See DIAGNOSTIC TROUBLE CODE CHART ).
  If the malfunction does not reoccur in 3 consecutive trips, the MIL goes off automatically but the DTCs remain recorded in the ECM memory.
  
  Fig 1: Locating Malfunction Indicator
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- To check the DTC, connect the hand-held tester or OBD II scan tool to the Data Link Connector 3 (DLC3) of the vehicle. The hand-held tester or OBD II scan tool also enables you to erase the DTC and check the freeze frame data and various forms of engine data (See the instruction manual for the OBD II scan tool or the hand-held tester). The DTC includes SAE controlled codes and manufacturer controlled codes. SAE controlled codes must be set according to the SAE, while manufacturer controlled codes can be set by a manufacturer with certain restrictions (See the DTC chart on DIAGNOSTIC TROUBLE CODE CHART ).
  
  Fig 2: Connecting Hand Held Tester To DLC3
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- The diagnosis system operates in "normal mode" during normal vehicle use. In "normal mode", 2 trip detection logic* is used to ensure accurate detection of malfunctions. A "check mode" is also available to technicians as an option. In "check mode", 1 trip detection logic is used for simulating malfunction symptoms and increasing the system's ability to detect malfunctions, including intermittent malfunctions (hand-held tester only) (See step 3).
- *2 trip detection logic:
  When a malfunction is first detected, the malfunction 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 illuminate. This is known as 2nd trip detection.
- Freeze frame data:
  The freeze frame data records the engine conditions (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 determining 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).

Check the DLC3.

The vehicle's ECM uses the ISO 9141-2 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

Fig 3: LOCATING DATA LINK CONNECTOR 3 (DLC3)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TERMINAL REFERENCE

Symbol	Name	Result
(Terminal No.)	(Reference terminal)	(Condition)
SIL	Bus "+" line	Pulse generation
(7)	(5 - Signal ground)	(During transmission)
CG	Chassis ground	1 Ω or less
(4)	(Body ground)	(Always)
SG	Signal ground	1 Ω or less
(5)	(Body ground)	(Always)
BAT	Battery positive	9 to 14 V
(16)	(Body ground)	(Always)

NOTE:

Connect the cable of the hand-held tester to the DLC3, turn the ignition switch ON and attempt to use the hand-held tester. If the screen displays UNABLE TO CONNECT TO VEHICLE, a problem exists in the vehicle side or the tester side.

If the communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
If the communication is still impossible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.

Inspect the battery voltage.
Battery Voltage: 11 to 14 V

If voltage is below 11 V, recharge the battery before proceeding.
Check the MIL.
1. The MIL comes on when the ignition switch is turned ON and the engine is not running.
  HINT:
  
  If the MIL is not illuminated, troubleshoot the MIL circuit (See MIL CIRCUIT ).
2. When the engine is started, the MIL should not illuminate. If the lamp remains on, the diagnosis system has detected a malfunction or abnormality in the system.

DTC CHECK (Normal Mode)
CAUTION:
- If no DTC appears in normal mode:
  On the OBD II scan tool or the hand-held tester check the pending fault code using the Continuous Test Results 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.
1. Checking DTCs using the OBD II scan tool or hand-held tester.
  1. Connect the OBD II scan tool or the hand-held tester to DLC3.
    
    Fig 4: CONNECTING HAND HELD TESTER TO DATA LINK CONNECTOR 3 (DLC3)
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  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 menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES. For the OBD II scan tool, see its instruction manual.
  4. See DIAGNOSTIC TROUBLE CODE CHART to confirm the details of the DTCs.
  CAUTION:
  When simulating a symptom with the OBD II scan tool (excluding hand-held tester) to check the DTCs, use the normal mode. For DTCs chart subject to "2 trip detection logic", 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 / PENDING 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.
  - Check the pending fault code using the Continuous Test Results function (Mode 7 for SAE J1979) on the OBD II scan tool.
2. 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 tester 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.
3. 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 "INITIALIZE procedure.
DTC CHECK (Check Mode)
NOTE:
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.
1. Follow these steps when preparing to use the hand-held tester check mode.
  
  Fig 5: CONNECTING HAND HELD TESTER TO DATA LINK CONNECTOR 3 (DLC 3)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  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 Fig 6.
  6. Start the engine. The MIL should turn off after the engine starts.
  7. Simulate the conditions of the malfunction described 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 circuit.
2. Clearing DTCs using the OBD II scan tool or the hand-held tester.
  1. Connect the OBD II scan tool or the hand-held tester 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: DIAGNOSTICS ENHANCED OBD II / DTC INFO / CLEAR CODES; and 2) press YES. For the OBD II scan tool, see its instruction manual.
3. Clearing the DTCs without 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 "INITIALIZE" procedure.
FAIL-SAFE CHART
If any of the following code is recorded, the ECM enters fail-safe mode.

Fig 7: ECM FAIL-SAFE CHART
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:

Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.
1. Clear the DTCs. (See step 2)
2. Set the check mode. (See step 3)
3. Perform a simulation test (See HOW TO PROCEED WITH TROUBLESHOOTING ).
4. Check the connector and terminal (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
5. Wiggle the harness and connector (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
BASIC INSPECTION
When the malfunction is not confirmed in the DTC check, troubleshooting should be carried out in all the possible circuits considered as causes of the problem. In many cases, by carrying out the basic engine check shown in the following flowchart, the location causing the problem can be found quickly and efficiently. Therefore, using this check is essential in the engine troubleshooting.
1. Is battery positive voltage 11 V or more when engine stopped?
  1. NO: Charge or replace battery.
  2. YES: Go to next Step
2. Is engine cranked?
  1. NO: Proceed to NO-START and STARTER RELAY TEST , and continue to troubleshoot.
  2. YES: Go to Next Step
3. Does engine start?
  1. NO: Go to step 6 .
  2. YES: Go to Next Step
4. Check air filter.
  PREPARATION:
  
  Remove the air filter.
  
  CHECK:
  
  Visual check that the air filter is not excessively dirty or oily.
  1. NG: Repair or replace air filter.
  2. OK: Go to Next Step
5. Check idle speed.
  PREPARATION:
  1. Warm up the engine to the normal operating temperature.
  2. Switch off all the accessories.
  3. Switch off the A/C.
  4. Shift the transmission into the N position.
  5. Connect the OBD II scan tool or hand-held tester to the DLC3 of the vehicle.
  CHECK:
  
  Use CURRENT DATA to check the idle speed.
  
  OK:
  1. Idle speed:
  2. 650 to 750 RPM
  1. NG: Proceed to problem symptoms table on PROBLEM SYMPTOMS TABLE .
  2. OK: Go to Next Step
6. Check fuel pressure.
  PREPARATION:
  1. Be sure that enough fuel is in the tank.
  2. Connect the hand-held tester to the DLC3.
  3. Turn the ignition switch ON and push the hand-held tester main switch ON.
  4. Use the ACTIVE TEST mode to operate the fuel pump.
  5. Please refer to the hand-held tester operator's manual for further details.
  6. If you have no hand-held tester, connect the positive (+) and negative (-) leads from the battery to the fuel pump connector (See ON-VEHICLE INSPECTION ).
  Fig 8: Locating Screw & Pulsation Damper
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  CHECK:
  
  Check that the pulsation damper screw rises up when the fuel pump operation (See ON-VEHICLE INSPECTION ).
  
  HINT:
  
  At this time, you will hear a fuel flowing noise.
  1. NG: Proceed to ON-VEHICLE INSPECTION and continue to troubleshoot.
  2. OK: Go to Next Step
7. Check for spark.
  PREPARATION:
  1. Disconnect the ignition coil.
  2. Remove the spark plug.
  3. Install the spark plug to the ignition coil.
  4. Disconnect the injector connector.
  5. Ground the spark plug.
  CHECK:
  
  Check if spark occurs while the engine is being cranked.
  
  Fig 9: SPARKING CHECK
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  NOTE: To prevent excess fuel from being injected from the injectors during this test, don't crank the engine for more than 5 to 10 seconds at a time.
  1. NG: Proceed to ON-VEHICLE INSPECTION and continue to troubleshoot.
  2. OK: Proceed to problem symptoms table on PROBLEM SYMPTOMS TABLE .
DATA LIST
HINT:

Using the hand-held tester DATA LIST allows switch, sensor, actuator and other item values to be read without removing any parts. Reading the DATA LIST early in troubleshooting is one way to shorten labor time.

NOTE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.
1. Warm up the engine.
2. Turn the ignition switch OFF.
3. Connect the hand-held tester or the OBD II scan tool to the DLC3.
4. Turn the ignition switch ON.
5. Push the "ON" button of the hand-held tester.
6. Enter the following menus: DIAGNOSTICS / ENHANCED OBD II / DATA LIST.
7. According to the display on tester, read the "DATA LIST".
Fig 10: Diagnostics Data List (1 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 11: Diagnostics Data List (2 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
ACTIVE TEST
HINT:

Performing the ACTIVE TEST using the hand-held tester or the OBD II scan tool allows the relay, VSV, actuator and so on to operate without parts removal. Performing the ACTIVE TEST as a first step of troubleshooting is one method to shorten diagnostic time.

It is possible to display the DATA LIST during the ACTIVE TEST.
1. Warm up the engine.
2. Turn the ignition switch OFF.
3. Connect the hand-held tester or the OBD II scan tool to the DLC3.
4. Turn the ignition switch ON.
5. Push the "ON" button of the hand-held tester or the OBD II scan tool.
6. Enter the following menus: DIAGNOSTICS / ENHANCED OBD II / ACTIVE TEST.
7. According to the display on tester, perform the "ACTIVE TEST".
Fig 12: Diagnostic Active Test Table
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DEFINITION OF TERMS

TERMS & DEFINITION

Term	Definition
Monitor description	Description of what the ECM monitors and how it detects malfunctions (monitoring purpose and its details).
Related DTCs	Diagnostic code
Typical enabling condition	Preconditions that allow the ECM to detect malfunctions. With all preconditions satisfied, the ECM sets the DTC when the monitored value(s) exceeds the malfunction threshold(s).
Sequence of operation	The priority order that is applied to monitoring, if multiple sensors and components are used to detect the malfunction. When a sensor is being monitored, the next sensor or component will not be monitored until the sensor monitoring is finished.
Required sensor/components	The sensors and components that are used by the ECM to detect malfunctions.
Frequency of operation	The number of times that the ECM checks for malfunctions per driving cycle. "Once per driving cycle" means that the ECM detects the malfunction only one time during a single driving cycle. "Continuous" means that the ECM detects malfunction every time an enabling condition is met.
Duration	The minimum time that the ECM must sense a continuous deviation in the monitored value(s) before setting a DTC. This timing begins after the "typical enabling conditions" are met.
Malfunction thresholds	Beyond this value, the ECM will conclude that there is a malfunction and set a DTC.
MIL operation	MIL illumination timing after a defect is detected. "Immediately" means that the ECM illuminates MIL the instant the ECM determines that there is a malfunction. "2 driving cycle" means that the ECM illuminates MIL if the same malfunction is detected again in the 2nd driving cycle.

TOYOTA/LEXUS PART AND SYSTEM NAME LIST

This reference list indicates the part names used in this manual along with their definitions.

PARTS & DEFINITION

TOYOTA/LEXUS name	Definition
Toyota HCAC system, Hydro-carbon Adsorptive Catalyst (HCAC) system, HC adsorptive three-way catalyst	HC adsorptive three-way catalytic converter
Variable Valve Timing sensor, VVT sensor	Camshaft position sensor
Variable valve timing system, VVT system	Camshaft timing control system
Camshaft timing oil control valve, Oil control valve, OCV, VVT, VSV	Camshaft timing oil control valve
Variable timing and lift, VVTL	Camshaft timing and lift control
Crankshaft position sensor "A"	Crankshaft position sensor
Engine speed sensor	Crankshaft position sensor
THA	Intake air temperature
Knock control module	Engine knock control module
Knock sensor	Engine knock sensor
Mass or volume air flow circuit	Mass air flow sensor circuit
Vacuum sensor	Manifold air pressure sensor
Internal control module, Control module, Engine control ECU, PCM	Power train control module
FC idle	Deceleration fuel cut
Idle air control valve	Idle speed control
VSV for CCV, Canister close valve VSV for canister control	Evaporative emissions canister vent valve
VSV for EVAP, Vacuum switching valve assembly No. 1, EVAP VSV, Purge VSV	Evaporative emissions canister purge valve
VSV for pressure switching valve, Bypass VSV	Evaporative emission pressure switching valve
Vapor pressure sensor, EVAP pressure sensor, Evaporative emission control system pressure sensor	Fuel tank pressure sensor
Charcoal canister	Evaporative emissions canister
ORVR system	On-board refueling vapor recovery system
Intake manifold runner control	Intake manifold tuning system
Intake manifold runner valve, IMRV, IACV (runner valve)	Intake manifold tuning valve
Intake control VSV	Intake manifold tuning solenoid valve
AFS	Air fuel ratio sensor
O2 sensor	Heater oxygen sensor
Oxygen sensor pumping current circuit	Oxygen sensor output signal
Oxygen sensor reference ground circuit	Oxygen sensor signal ground
Accel position sensor	Accelerator pedal position sensor
Throttle actuator control motor, Actuator control motor, Electronic throttle motor, Throttle control motor	Electronic throttle actuator
Electronic throttle control system, Throttle actuator control system	Electronic throttle control system
Throttle/pedal position sensor, Throttle/pedal position switch, Throttle position sensor/switch	Throttle position sensor
Turbo press sensor	Turbocharger pressure sensor
Turbo VSV	Turbocharger pressure control solenoid valve
P/S pressure switch	Power-steering pressure switch
VSV for ACM	Active control engine mount
Speed sensor, Vehicle speed sensor "A", Speed sensor for skid control ECU	Vehicle speed sensor
ATF temperature sensor, Trans. fluid temp. sensor, ATF temperature sensor "A"	Transmission fluid temperature sensor
Electronic controlled automatic transmission, ECT	Electronically controlled automatic
Intermediate shaft speed sensor "A"	Counter gear speed sensor
Output speed sensor	Output shaft speed sensor
Input speed sensor, Input turbine speed sensor "A", Speed sensor (NT), Turbine speed sensor	Input turbine speed sensor
PNP switch, NSW	Park/neutral position switch
Pressure control solenoid	Transmission pressure control solenoid
Shift solenoid	Transmission shift solenoid valve
Transmission control switch, Shift lock control unit	Shift lock control module
Engine immobiliser system, Immobiliser system	Vehicle anti-theft system

The monitor will run whenever the following DTCs are not present (Monitor disablement List)
HINT:

This table indicates ECM monitoring status for the items in the upper columns if the DTCs in each line on the left are being set.

As for the "X" mark, when the DTC on the left is stored, detection of the DTC in the upper column is not performed.

Fig 13: Monitor Disablement List (1 Of 6)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 14: Monitor Disablement List (2 Of 6)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 15: Monitor Disablement List (3 Of 6)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 16: Monitor Disablement List (4 Of 6)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 17: Monitor Disablement List (5 Of 6)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 18: Monitor Disablement List (6 Of 6)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

O2S TEST RESULT

INTRODUCTION

The O2S TEST RESULT refers to the results of the engine control module (ECM) when it monitors the oxygen sensor (O2S), and it can be read using the hand-held tester or the generic OBD II scan tool. Based on this, you can find the O2S's conditions.

The ECM monitors the O2S in the various items. You can read the monitor result (TEST DATA) of each monitor item using the O2S TEST RESULT. However, the output value of the TEST DATA is the latest "snapshot" value that is taken after monitoring and therefore is not dynamic.

In this repair manual, the description of the O2S TEST RESULT (for O2S related DTCs) are written in a table.

This table consists of 5 items:

TEST ID (a code applied to each TEST DATA)
Description of TEST DATA
Conversion Factor (When Conversion Factor has a value written in the table, multiply the TEST DATA value appearing on the scan tool by the Conversion Factor value. The result will be the required value.)
Unit
Standard Value

If the TEST DATA value appearing on the scan tool is out of the standard value, the O2S is malfunctioning. If it is within the standard value, the O2S is functioning normally. However, if the value is on the borderline of the standard value, the O2S may malfunction very soon.

HOW TO READ O2S TEST RESULT USING HAND-HELD TESTER

Connect the hand-held tester to the DLC3.
On the tester screen, select the following menus: DIAGNOSTICS/CARB OBDII/O2S TEST RESULT. A list of the O2S equipped on the vehicle will be displayed.

Fig 19: O2 SENSOR TEST RESULT SCREEN
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Select the desired O2S and press ENTER. The following screen will appear.
Press HELP and * simultaneously. More information will appear.
Example:
1. The hand-held tester displays "17" as a value of the "TIME $81" (see the illustration on the left).
2. Find the Conversion Factor value of "TIME $81" in the O2S TEST RESULT chart below. 0.3906 is specified for $81 in this chart.
3. Multiply "17" in step (1) by 0.3906 (Conversion Factor) in the step (2).
  17 x 0.3906 = 6.6%
4. If the answer is within the standard value, the "TIME $81" can be confirmed to be normal.

Fig 20: TEST DATA SCREEN

O2S TEST RESULT Chart

TEST ID	Description of TEST DATA	Conversion Factor	Unit	Standard Value
$81	Percentage of monitoring time when the HO2S voltage is less than 0.05V	Multiply 0.3906	%	Within 60 %

CHECKING MONITOR STATUS
NOTE: The Monitor Status is not applicable to the heated oxygen sensor (HO2S). The HO2S status can be checked with O2S TEST RESULT.
1. INTRODUCTION
  The purpose of the monitor result (mode 6) is to allow access to the results for on-board diagnostic monitoring tests of specific components/systems that are not continuously monitored. Examples are catalyst, EVAP and thermostat.
  
  The monitor result allows the OBD scan tool to display the monitor status, test value and test limit. The monitor status indicates whether the component is functioning normally or not (PASS or FAIL). The test value is the value that was used to determine the monitor status. When the test value is inside the test limit, the ECM determines the component is functioning normally (PASS). If the test value is outside the test limit, the ECM determines the component is malfunctioning (FAIL).
  
  A problem in these components/systems can be found by comparing the test value and test limit. The monitor result information is included under "MONITOR RESULT" in the DTC sections.
2. PROCEDURE
  NOTE: The monitor result and test value are cleared when the ignition switch is turned OFF.
  1. Connect the hand-held tester to the DLC3.
  2. Turn the ignition switch ON.
  3. Clear the DTCs.
  4. Run the vehicle in accordance with the applicable drive pattern described in READINESS MONITOR DRIVE PATTERN .
  5. Select from the tester menus: DIAGNOSTICS, ENHANCED OBD II, MONITOR INFO and MONITOR RESULT. The monitor result appears after the component name.
    INCMP: The component has not been monitored yet.
    
    PASS: The component is functioning normally.
    
    FAIL: The component is malfunctioning.
  6. Confirm that the component is set to either PASS or FAIL.
    
    Fig 21: Monitor Result Screen
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. Select the component (Label) and press ENTER. The accuracy test value appears when the monitor result is either PASS or FAIL.
    VAL The test value
    
    LMT: The test limit
    
    TLT: The test limit type. Either 0 or 1 is displayed.
  8. If TLT is 0, the component is malfunctioning when the test value is higher than the test limit. If TLT is 1, the component is malfunctioning when the test value is lower than the test limit.
  9. Compare the test value with the test limit. The test value is usually significantly higher or lower than the test limit. If the test value is on the borderline of the test limit, there is a potential malfunction in the component.
Fig 22: Component Malfunction Result Screen
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

The monitor result might on rare occasions be PASS even if the MIL is illuminated. This indicates the system malfunctioned on a previous driving cycle. This might be caused by an intermittent problem.