Engine Control System Self Diagnostics - Land Cruiser Toyota Land Cruiser 100 рестайлинг

INTRODUCTION

Note. Before performing testing procedures, check for any related Technical Service Bulletins (TSBs).

To properly diagnosis and repair this vehicle, follow TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM. If no Diagnostic Trouble Codes (DTC) are present and a no start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If no DTCs are present and a driveability condition exists, proceed to TROUBLESHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).

SYSTEM OVERVIEW

Engine Control Module (ECM) monitors engine operation and contains a self-diagnostic system which stores Diagnostic Trouble Codes (DTC) and complies to On-Board Diagnostics Generation II (OBD-II) standards. Since the various components need to be monitored during different driving conditions, the OBD II system is designed to run separate monitoring programs called Readiness Monitors. Many state emissions inspection and maintenance (I/M) programs require that vehicles complete their Readiness Monitors before beginning an emissions test. See OBD MONITOR & DRIVE CYCLE PATTERNS specific to this vehicle.

Self-diagnostic system is used to provide vehicle with an on-board diagnostic system which is capable of continuously monitoring efficiency of emission control system and improving diagnosis and repair when system failures occur.

OBD-II regulations require that Malfunction Indicator Light (MIL) must be illuminated when a malfunction exists in the emission control system which affects vehicle emissions or a malfunction exists in the ECM. MIL may also be illuminated when a DTC is stored in the ECM memory due to a system or component failure. MIL is displayed as an engine icon located just below the speedometer on instrument cluster on instrument panel. MIL may also be referred to as CHECK ENGINE light.

If malfunction does not reoccur in 3 consecutive trips, MIL will turn off, but DTCs remain stored in ECM memory. DTCs may be retrieved using an OBD-II scan tool that complies with SAE standard J-1978, SAE standard J-1979 or Toyota hand-held tester connected to Data Link Connector (DLC3). Scan tool or Toyota hand-held tester may also be used to provide freeze frame data and to clear DTCs from ECM. For additional information on freeze frame data, see FREEZE FRAME DATA .

TWO-TRIP DETECTION LOGIC

When a malfunction initially occurs, Diagnostic Trouble Code (DTC) will be temporarily stored in ECM memory but Malfunction Indicator Light (MIL) will not illuminate. The second time malfunction is detected, MIL will illuminate provided ignition is turned off and then back on after first malfunction was detected. This is referred to as "Two-Trip Detection Logic" and only applies to specific DTCs. When road testing vehicle in CHECK mode using Toyota hand-held tester, two-trip detection logic will not function and MIL will illuminate the first time a malfunction is detected.

DATA LINK CONNECTOR

OBD-II regulations (SAE J-1962) standardizes configuration of Data Link Connector (DLC3). DLC3 is located at driver's side of instrument panel. (Scheme 58)

Scheme 58

FREEZE FRAME DATA

Engine Control Module (ECM) records engine operating conditions when a misfire or fuel trim (mixture) malfunction or when various other malfunctions exist. ECM records engine operating conditions for the fuel system, calculated load, engine coolant temperature, engine speed, vehicle speed and etc. when a malfunction exists. This information is referred to as freeze frame data. If more than one Diagnostic Trouble Code (DTC) exists, only freeze frame data for the first DTC is recorded. Freeze frame data is useful for determining conditions when a malfunction occurred. OBD-II scan tool or Toyota hand-held tester may by used to read freeze frame data.

MALFUNCTION INDICATOR LIGHT INSPECTION

Note. Malfunction Indicator Light (MIL) may also be referred to as CHECK ENGINE light. Inspect MIL to ensure it is operational and will come on if a Diagnostic Trouble Code (DTC) is set.

1. Turn ignition on with engine off. MIL should come on and remain on. MIL is displayed as an engine icon located just below speedometer on instrument cluster on instrument panel. If MIL comes on, go to next step. If MIL does not come on, check bulb circuit on instrument cluster and White and Light Blue wires and electrical connectors between MIL and Engine Control Module (ECM). See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. ECM is located behind glove box. (Scheme 64)
2. Start engine and ensure MIL goes off. If MIL goes off, no malfunction is detected at this time. If MIL remains on or blinks with engine running, a malfunction is detected. Proceed to «TESTING PROCEDURE»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__testing-procedure).

TESTING PROCEDURE

To ensure correct diagnosis and repair, testing should be done in the following sequence

1. Record Customer Complaint - Ensure all customer complaints or observations are recorded. Test drive vehicle with customer when necessary for malfunction verification.
2. Retrieve Diagnostic Trouble Codes - Using Toyota hand-held tester or scan tool, retrieve Diagnostic Trouble Codes (DTC) from Engine Control Module (ECM) and record any freeze frame data (if applicable). See «RETRIEVING DIAGNOSTIC TROUBLE CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__retrieving-diagnostic-trouble-codes) .
3. Clear Diagnostic Trouble Codes - Using Toyota hand-held tester or scan tool, clear DTCs and freeze frame data from ECM. See «CLEARING DIAGNOSTIC TROUBLE CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__clearing-diagnostic-trouble-codes) .
4. Visual Inspection - Inspect all electrical connectors and wiring for suspected circuit or component. Ensure all connections are clean and tight.
5. Confirm Symptoms & Diagnostic Trouble Codes - Perform road test. Determine if original symptoms still exist. Using scan tool or Toyota hand-held tester, retrieve DTCs from ECM. See «RETRIEVING DIAGNOSTIC TROUBLE CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__retrieving-diagnostic-trouble-codes) .
6. Diagnose & Repair Diagnostic Trouble Codes - Perform appropriate DTC test listed under DIAGNOSTIC TESTS as necessary. For DTC descriptions, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser) under DIAGNOSTIC TROUBLE CODE DEFINITIONS. If no DTCs are present and a no start condition exists, proceed to «BASIC DIAGNOSTIC PROCEDURES - V6 & V8»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-controls-basic-diagnostic-procedures-v6-v8) article. If no DTCs are present and a driveability condition exists, proceed to «TROUBLESHOOTING - NO CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-controls-trouble-shooting-no-codes) article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).
7. Verification Procedure - After repairs have been completed, clear all DTCs from ECM. See «CLEARING DIAGNOSTIC TROUBLE CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__clearing-diagnostic-trouble-codes) . Perform road test. Ensure no DTCs exist and all symptoms and/or complaints have been repaired.

EVAP Monitor & Drive Cycle Pattern

For EVAP monitor and drive cycle pattern (Scheme 59)and (Scheme 60).

Scheme 59

Scheme 60

Heated Oxygen Sensor Monitor & Drive Cycle Pattern

For heated oxygen sensor monitor and drive cycle pattern (Scheme 61)

Scheme 61

Oxygen Sensor Heater & A/F Sensor Heater Monitor & Drive Cycle Pattern

For oxygen sensor heater and A/F sensor heater monitor and drive cycle pattern (Scheme 62)

Scheme 62

Catalyst Monitor & Drive Cycle Pattern

For catalyst monitor and drive cycle pattern (Scheme 63)

Scheme 63

RETRIEVING DIAGNOSTIC TROUBLE CODES

Note. Diagnostic Trouble Codes (DTC) may be retrieved using Toyota hand-held tester or On-Board Diagnostic (OBD-II) scan tool that complies with SAE standard J-1978, or SAE standard J-1979. Toyota hand-held tester or OBD-II scan tool may be operated in NORMAL mode when retrieving DTCs. Only Toyota hand-held tester or an Enhanced On-Board Diagnostic (OBD-II) scan tool that complies with SAE standard J-1979 may be used in CHECK mode (OBD II scan tool Check Mode 7) when retrieving DTCs.

NORMAL mode is used to retrieve DTCs from Engine Control Module (ECM). CHECK mode is used to check for DTCs when operating vehicle to simulate conditions during which DTC was set. CHECK mode contains a higher sensing ability to detect malfunctions. CHECK mode helps determine malfunctions caused by poor electrical connections or intermittent problems which are difficult to determine using NORMAL mode.

Note. If using Toyota hand-held tester, when ignition switch is turned from ON to ACC or OFF position during CHECK mode, hand-held tester is switched from NORMAL mode to CHECK mode or from CHECK MODE to NORMAL mode, all DTCs and freeze frame data will be erased from ECM. DO NOT switch modes until all DTCs and freeze frame data have been recorded.

NORMAL Mode Diagnostic Trouble Code Retrieval

1. Connect Toyota hand-held tester or scan tool to Data Link Connector (DLC3) at driver's side of instrument panel. (Scheme 58) Turn ignition on with engine off. Turn hand-held tester or scan tool on. Using hand-held tester or scan tool manufacturer's instructions, check for DTCs and freeze frame data.
2. If hand-held tester or scan tool does not display UNABLE TO CONNECT TO VEHICLE, go to next step. If hand-held tester or scan tool displays UNABLE TO CONNECT TO VEHICLE, check DLC3. See «DATA LINK CONNECTOR (DLC3) INSPECTION»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser) under SCAN TOOL PROBLEMS.
3. Record any DTCs and freeze frame data displayed for system diagnosis. If driveability problem exists and no DTCs are present, go to «TROUBLESHOOTING - NO CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-controls-trouble-shooting-no-codes) article for diagnosis by symptom.
4. If any DTCs exist, perform appropriate DTC test under «DIAGNOSTIC TESTS»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__diagnostic-tests). For DTC descriptions, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser) under DIAGNOSTIC TROUBLE CODE DEFINITIONS. For more information on freeze frame data, see «FREEZE FRAME DATA»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__freeze-frame-data). For information on two-trip detection logic DTCs, see «TWO-TRIP DETECTION LOGIC»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__two-trip-detection-logic).
5. After repairs for DTC have been completed, DTC must be cleared from ECM. See «CLEARING DIAGNOSTIC TROUBLE CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__clearing-diagnostic-trouble-codes). Road test vehicle to ensure all symptoms and/or complaints have been repaired.

CHECK Mode Diagnostic Trouble Code Retrieval (Hand-Held Tester Only)

Note. If using Toyota hand-held tester, if ignition switch is turned from ON to ACC or OFF position during CHECK mode, all DTCs and freeze frame data will be erased from Engine Control Module (ECM). DO NOT switch from CHECK MODE to NORMAL mode until all DTCs and freeze frame data are recorded.

1. Ensure vehicle battery is fully charged. Apply parking brake. Place transmission in Park or Neutral. Ensure A/C and ignition are off. Check that throttle valve is fully closed. Connect hand-held tester to Data Link Connector (DLC3) at driver's side of instrument panel. (Scheme 58) Turn ignition on and then turn hand-held tester on.
2. Switch hand-held tester from NORMAL mode to CHECK mode. Ensure Malfunction Indicator Light (MIL) on instrument cluster flashes to indicate CHECK mode operation. Start engine. If no DTCs are present, MIL will turn off. Try to simulate conditions of driveability complaint described by customer.
3. Record any DTCs and freeze frame data displayed for system diagnosis. If driveability problem exists and no DTCs are present, go to «TROUBLESHOOTING - NO CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-controls-trouble-shooting-no-codes) article for diagnosis by symptom.
4. If any DTCs are present, perform appropriate DTC test under «DIAGNOSTIC TESTS»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__diagnostic-tests). For DTC description, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser) under DIAGNOSTIC TROUBLE CODE DEFINITIONS. For more information on freeze frame data, see «FREEZE FRAME DATA»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__freeze-frame-data). For information on two-trip detection logic DTCs, see «TWO-TRIP DETECTION LOGIC»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__two-trip-detection-logic).
5. After repairs for DTC have been completed, DTC must be cleared from ECM. See «CLEARING DIAGNOSTIC TROUBLE CODES»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser__clearing-diagnostic-trouble-codes). Road test vehicle to ensure all symptoms and/or complaints have been repaired.

CLEARING DIAGNOSTIC TROUBLE CODES

1. After repairs for Diagnostic Trouble Codes (DTC) have been completed, DTCs and freeze frame data should be cleared from Engine Control Module (ECM) memory. Using scan tool or Toyota hand-held tester, follow the manufacturer's instructions and clear DTCs and freeze frame data from ECM.
2. DTCs and freeze frame data may also be cleared by removing EFI or ECD fuse No.1 for about 1 minute. EFI or ECD fuse No. 1 is located in fuse/relay box at driver's side front corner of engine compartment. DTCs and freeze frame data may also be cleared by disconnecting negative battery cable. However, other various memory functions such as the clock, radio, alarm, seats, etc. will be cleared and must be reset. For programming procedures, see «COMPUTER RELEARN PROCEDURES - TOYOTA»(/toyota/land-cruiser/100-2002-2005/remont/computer-relearn/#computer-relearn-procedures) article in GENERAL INFORMATION.

ENGINE CONTROL MODULE LOCATION

Engine Control Module (ECM) is located behind glove box. (Scheme 64)

Scheme 64

TEST DRIVE CONFIRMATION

1. On certain Diagnostic Trouble Codes (DTC), once DTC has been cleared from Engine Control Module (ECM) memory, test drive confirmation can be performed to verify repairs are made and that DTC does not reset. Test drive confirmation will duplicate conditions required to set specified DTCs.
2. Test drive confirmation lists the procedure to be performed to check that DTC does not reset. Test drive confirmation applies only to specific DTCs. Test drive confirmation will be included within proper DTC test under DIAGNOSTIC TESTS.

ENGINE CONTROL MODULE PROGRAMMING

An engine immobilizer system is used. If Engine Control Module (ECM) is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - TOYOTA article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

Scheme 65

1. If Toyota hand-held tester or scan tool displays UNABLE TO CONNECT TO VEHICLE when hand-held tester or scan tool is connected to Data Link Connector (DLC3), try hand-held tester or scan tool on another vehicle. If hand-held tester or scan tool operates on another vehicle, go to next step. If hand-held tester or scan tool does not operate on another vehicle, problem is probably with hand-held tester or scan tool.
2. Check voltage and resistance between ground and specified terminal on DLC3. See «DATA LINK CONNECTOR (DLC3) VOLTAGE & RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-control-system-self-diagnostics-land-cruiser). (Scheme 65) If voltage or resistance are not within specification, check wiring circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For full wiring diagram of DLC3, it may be necessary to see DATA LINK CONNECTORS in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. DATA LINK CONNECTOR (DLC3) VOLTAGE & RESISTANCE SPECIFICATIONS Terminal No. (Circuit) Specification 4 (Chassis Ground) 1 Ohm Or Less 5 (Signal Ground) 1 Ohm Or Less 7 (BUS Communication) (1) 16 (Battery Voltage) 9-14 Volts (1) Pulse generation should exist during information transmission from Engine Control Module (ECM).

SUMMARY

If no Diagnostic Trouble Codes (DTC) are present and a no start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If no DTCs are present and a driveability condition exists, proceed to TROUBLESHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TESTS

Note. Before performing any diagnostic test, refer to SELF-DIAGNOSTIC SYSTEM for diagnostic system functions and system diagnostic procedures. Also check for any related Technical Service Bulletins (TSBs).

Note. When performing diagnostic tests, it may be necessary to identify Engine Control Module (ECM) electrical connector terminals which are referenced to in testing procedure. (Scheme 66)

For location of emission related components (Scheme 67)

Scheme 66

Scheme 67

DTC P0031, DTC P0032, DTC P0037, DTC P0038, DTC P0051, DTC P0052, DTC P0057 OR DTC P0058

Code Definition

1. DTC P0031: Oxygen Sensor Heater Control Circuit (Bank 1 Sensor 1)
2. DTC P0032: Oxygen Sensor Heater Control Circuit (Bank 1 Sensor 1)
3. DTC P0037: Oxygen Sensor Heater Control Circuit (Bank 1 Sensor 2)
4. DTC P0038: Oxygen Sensor Heater Control Circuit (Bank 1 Sensor 2)
5. DTC P0051: Oxygen Sensor Heater Control Circuit (Bank 2 Sensor 1)
6. DTC P0052: Oxygen Sensor Heater Control Circuit (Bank 2 Sensor 1)
7. DTC P0057: Oxygen Sensor Heater Control Circuit Low (Bank 2 Sensor 2)
8. DTC P0058: Oxygen Sensor Heater Control Circuit (Bank 2 Sensor 2)

Circuit Description

For circuit description (Scheme 68)

Scheme 68

Possible Causes

These DTCs use two-trip detection logic. DTC is set when heated oxygen sensor heater current draw exceeds 2 amps or heated oxygen sensor heater current draw is 0.2 amp or less when heater operates. If DTC exists, ECM will operate in fail-safe mode and the heater on oxygen sensor will be turned off. Possible causes are

1. Heated oxygen sensor heater circuit is open or shorted.
2. Defective heated oxygen sensor heater.
3. Defective ECM.

Diagnosis & Repair

Note. Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 69) To check HO2S heater resistance (Scheme 71)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For HO2S circuit wiring diagram (Scheme 70) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 69

Scheme 70

Scheme 71

DTC P0100, DTC P0102 OR DTC P0103

Code Definition

1. DTC P0100: Mass Airflow Meter Circuit
2. DTC P0102: Mass Airflow Meter Circuit Low Input
3. DTC P0103: Mass Airflow Meter Circuit High Input

For circuit description (Scheme 72)

Scheme 72

DTC is set when an open or short is detected in mass airflow meter circuit for more than 3 seconds when engine speed is 4000 RPM or less. Possible causes are

1. Mass airflow meter circuit.
2. Mass airflow meter.
3. ECM.

Note. Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

After confirming DTC P0100, use Toyota hand-held tester or scan tool to access CURRENT DATA to confirm MAF meter air flow rate. If MAF meter air flow rate is 0.0 gm/sec., VG circuit may be open or shorted, or power source circuit may be open. If MAF meter air flow rate is 271.0 gm/sec. or more, EVG circuit may be open.

For diagnosis and repair procedure (Scheme 73)& (Scheme 74).

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For MAF meter circuit wiring diagram (Scheme 75) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 73

Scheme 74

Scheme 75

For circuit description (Scheme 72)

This DTC uses two-trip detection logic. DTC is set when ECM detects MAF meter output is greater than 2.2 volts with throttle valve closed for more than 10 seconds with engine speed of 900 RPM or less, or MAF meter output is less than 0.25 volt with Throttle Position (TP) sensor VTA circuit signal voltage of 0.1 volt or more for more than 6 seconds with engine speed of 0 RPM or more. Possible cause is defective MAF meter.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

Check for any other DTCs. If other DTCs exist, diagnose and repair those DTCs first and retest. If only DTC P0101 exists, replace MAF meter. MAF meter is bolted to top side of air intake hose, near upper cap on air cleaner assembly and contains a Black 5-pin electrical connector. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

DTC P0110, DTC P0112 OR DTC P0113

Code Definition

1. DTC P0110: Intake Air Temperature Sensor Circuit
2. DTC P0112: Intake Air Temperature Sensor Circuit Low Input
3. DTC P0113: Intake Air Temperature Sensor Circuit High Input

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

Scheme 76

For circuit description (Scheme 77)

Scheme 77

For DTC detection conditions and possible causes (Scheme 78)

Scheme 78

Note. Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

After confirming DTC P0110, use Toyota hand-held tester or scan tool to access CURRENT DATA to read the intake air temperature for IAT sensor. If displayed intake air temperature is -40°F (-40°C), IAT sensor circuit may be open. If displayed intake air temperature is 284°F (140°C) or more, IAT sensor circuit may be shorted.

For IAT sensor circuit wiring diagram, diagnosis and repair procedure (Scheme 79)- (Scheme 81).

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 79

Scheme 80

Scheme 81

DTC P0115, DTC P0117 OR DTC P0118

Code Definition

1. DTC P0115: Engine Coolant Temperature Sensor Circuit
2. DTC P0117: Engine Coolant Temperature Sensor Circuit Low Input
3. DTC P0118: Engine Coolant Temperature Sensor Circuit High Input

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

Engine Coolant Temperature (ECT) sensor is a thermistor which monitors engine coolant temperature.

For DTC detection conditions and possible causes (Scheme 82)

Scheme 82

After confirming DTC P0115, use Toyota hand-held tester or scan tool to access CURRENT DATA to read the engine coolant temperature for ECT sensor. If displayed engine coolant temperature is -40°F (-40°C), ECT sensor circuit may be open. If displayed engine coolant temperature is 284°F (140°C) or more, ECT sensor circuit may be shorted.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For ECT sensor circuit wiring diagram, diagnosis and repair procedure (Scheme 83)- (Scheme 85).

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 83

Scheme 84

Scheme 85

DTC P0116: ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT RANGE/PERFORMANCE OR DTC P0125: INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP FUEL CONTROL

Note. If DTCs P0115 and P0116 are output simultaneously, an open may exist in wiring between Engine Coolant Temperature (ECT) sensor and Engine Control Module (ECM). Perform DTC P0115: ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT test before performing DTC P0116 test.

Engine Coolant Temperature (ECT) sensor is a thermistor which monitors engine coolant temperature.

This DTC uses two-trip detection logic. For DTC detection conditions and possible causes (Scheme 86)

Scheme 86

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 87) For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 87

DTC P0120, DTC P0122, DTC P0123, DTC P0220, DTC P0222, DTC P0223 OR DTC P2135

Code Definition

1. DTC P0120: Throttle/Pedal Position Sensor/Switch "A" Circuit
2. DTC P0122: Throttle/Pedal Position Sensor/Switch "A" Circuit Low Input
3. DTC P0123: Throttle/Pedal Position Sensor/Switch "A" Circuit High Input
4. DTC P0220: Throttle/Pedal Position Sensor/Switch "B" Circuit
5. DTC P0222: Throttle/Pedal Position Sensor/Switch "B" Circuit Low Input
6. DTC P0223: Throttle/Pedal Position Sensor/Switch "B" Circuit High Input
7. DTC P2135: Throttle/Pedal Position Sensor/Switch "A"/"B" Voltage Correlation

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

For circuit description (Scheme 88)

Scheme 88

For DTC detection conditions and possible causes (Scheme 89)

Scheme 89

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 91)- (Scheme 92).

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 93)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For TPS circuit wiring diagram (Scheme 90) For location of emission related components (Scheme 67)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For adjustments, see ON-VEHICLE ADJUSTMENTS - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 90

Scheme 91

Scheme 92

Scheme 93

For circuit description (Scheme 88)

For DTC detection conditions and possible causes (Scheme 94)

Scheme 94

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

TP sensor is defective. Replace throttle control motor and TP sensor. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

DTC P0128: THERMOSTAT MALFUNCTION

If the engine coolant temperature does not reach 167°F (75°C) after engine warm up, it is abnormal.

DTC is set when ECM detects engine coolant temperature is less than 167°F (75°C) when engine should be at normal operating temperature. Possible causes are

1. Defective cooling system thermostat.
2. Malfunction in cooling system.
3. Defective ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

1. Remove and inspect cooling system thermostat for damage and proper operation. Thermostat is located behind thermostat housing on passenger's side front of engine where upper radiator hose is attached. If thermostat is okay, go to next step. If thermostat is defective, replace thermostat.
2. Using Toyota hand-held tester or scan tool, check for any other DTCs. If other DTCs exist, diagnose and repair those DTCs first and retest. If only DTC P0128 exists, replace ECM. ECM is located behind glove box. (Scheme 64)

DTC P0130, DTC P0150, DTC P2195, DTC P2196, DTC P2197 OR DTC P2198

1. DTC P0130: Oxygen Sensor Circuit (Bank 1 Sensor 1)
2. DTC P0150: Oxygen Sensor Circuit (Bank 2 Sensor 1)
3. DTC P2195: Oxygen Sensor Signal Stuck Lean (Bank 1 Sensor 1)
4. DTC P2196: Oxygen Sensor Signal Stuck Rich (Bank 1 Sensor 1)
5. DTC P2197: Oxygen Sensor Signal Stuck Lean (Bank 2 Sensor 1)
6. DTC P2198: Oxygen Sensor Signal Stuck Rich (Bank 2 Sensor 1)

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

For circuit description (Scheme 68)

For DTC detection conditions and possible causes (Scheme 95)

Scheme 95

For Test Drive Confirmation Pattern (Scheme 96)

Scheme 96

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 97)- (Scheme 99).

When prompted to perform confirmation driving pattern, see TEST DRIVE CONFIRMATION .

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For HO2S circuit wiring diagram (Scheme 70) For location of emission related components (Scheme 67)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 97

Scheme 98

Scheme 99

DTC P0133: OXYGEN SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 1) OR DTC P0153: OXYGEN SENSOR CIRCUIT SLOW RESPONSE (BANK 2 SENSOR 1)

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

For circuit description (Scheme 68)

These DTCs use two-trip detection logic. DTC is set when ECM detects a response time of 1.1 seconds or more for heated oxygen sensor to change from rich to lean or from lean to rich with engine idling and at normal operating temperature. Possible causes are

1. Heated oxygen sensor circuit is open or shorted.
2. Defective heated oxygen sensor.
3. Air induction system malfunction.
4. Improper fuel pressure.
5. Defective fuel injector.
6. Defective ECM.

For Test Drive Confirmation Pattern (Scheme 96)

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 100)- (Scheme 102).

When prompted to perform confirmation driving pattern, see TEST DRIVE CONFIRMATION .

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For HO2S circuit wiring diagram (Scheme 70) For location of emission related components (Scheme 67)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 100

Scheme 101

Scheme 102

DTC P0134: HEATED OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SENSOR 1) OR DTC P0154: HEATED OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 2 SENSOR 1)

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

For circuit description (Scheme 68)

These DTCs use two-trip detection logic. For DTC detection conditions and possible causes (Scheme 103)

Scheme 103

For Test Drive Confirmation Pattern (Scheme 96)

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 104)- (Scheme 106).

When prompted to perform confirmation driving pattern, see TEST DRIVE CONFIRMATION .

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For HO2S circuit wiring diagram (Scheme 70) For location of emission related components (Scheme 67)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 104

Scheme 105

Scheme 106

DTC P0136: OXYGEN SENSOR CIRCUIT MALFUNCTION (BANK 1 SENSOR 2) OR DTC P0156: OXYGEN SENSOR CIRCUIT MALFUNCTION (BANK 2 SENSOR 2)

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

For circuit description (Scheme 68)

These DTCs use two-trip detection logic. For DTC detection conditions and possible causes (Scheme 107)

Scheme 107

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 108)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For HO2S circuit wiring diagram (Scheme 70) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 108

DTC P0171, DTC P0172, DTC P0174 OR DTC P0175

Code Definition

1. DTC P0171: System Too Lean (Bank 1)
2. DTC P0172: System Too Rich (Bank 1)
3. DTC P0174: System Too Lean (Bank 2)
4. DTC P0175: System Too Rich (Bank 2)

Note. These DTCs may be caused by the vehicle running out of fuel.

Note. If the vehicle runs out of fuel, the air-fuel ratio is LEAN and DTC P0171 and P0174 are recorded. The MIL then comes on.

Note. When DTC P0171 and P0174 are recorded, the actual air-fuel ratio is on the LEAN side. When DTCs P0172 and P0175 are recorded, the actual air-fuel ratio is on the RICH side.

Note. If the total of the short-term fuel trim value and long-term fuel trim value is within + or - 25 percent, the system is functioning normally.

For circuit description (Scheme 109)

Scheme 109

For DTC detection conditions and possible causes (Scheme 110)

Scheme 110

For Test Drive Confirmation Pattern (Scheme 96)

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 111)- (Scheme 114).

When prompted to perform confirmation driving pattern, see TEST DRIVE CONFIRMATION .

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For HO2S circuit wiring diagram (Scheme 70) For location of emission related components (Scheme 67)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 111

Scheme 112

Scheme 113

Scheme 114

DTC P0230: FUEL PUMP PRIMARY CIRCUIT

For circuit description (Scheme 115)

Scheme 115

DTC P0230 will set when an open or short in fuel pump relay circuit is detected. Possible causes are

1. Open or short in fuel pump relay circuit.
2. Defective circuit opening relay.
3. Defective fuel pump relay.
4. Defective fuel pump.
5. Defective ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 116)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For fuel pump circuit wiring diagram (Scheme 117) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 116

Scheme 117

DTC P0300 OR DTC P0301, DTC P0302, DTC P0303, DTC P0304, DTC P0305, DTC P0306, DTC P0307 OR DTC P0308

Code Definition

1. DTC P0300: Random/Multiple Cylinder Misfire Detected
2. DTC P0301: Cylinder No. 1 Misfire Detected
3. DTC P0302: Cylinder No. 2 Misfire Detected
4. DTC P0303: Cylinder No. 3 Misfire Detected
5. DTC P0304: Cylinder No. 4 Misfire Detected
6. DTC P0305: Cylinder No. 5 Misfire Detected
7. DTC P0306: Cylinder No. 6 Misfire Detected
8. DTC P0307: Cylinder No. 7 Misfire Detected
9. DTC P0308: Cylinder No. 8 Misfire Detected

Note. Cylinder No. 1 is front cylinder on driver's side of engine. Cylinder No. 2 is front cylinder on passenger's side of engine. Cylinders No. 1, 3, 5 and 7 are on driver's side of engine. Cylinders No. 2, 4, 6 and 8 are on passenger's side of engine.

Engine Control Module (ECM) uses input signals provided by crankshaft and camshaft position sensors to monitor the changes in crankshaft rotation. If engine speed rate changes enough to equal a preset number, a misfire is detected and Malfunction Indicator Light (MIL) is illuminated. If misfire rate is great enough and driving conditions will cause catalytic converter damage or overheating, the MIL will blink when misfire is occurring.

For DTC detection conditions and possible causes (Scheme 118)

Scheme 118

For Test Drive Confirmation Pattern (Confirmation Driving Pattern) (Scheme 119)

Scheme 119

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 120)- (Scheme 126).

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 127)- (Scheme 132).

When prompted to perform confirmation driving pattern, see TEST DRIVE CONFIRMATION .

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For fuel injector driver circuit wiring diagram (Scheme 133) For location of emission related components (Scheme 67)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For adjustments, see ON-VEHICLE ADJUSTMENTS - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 120

Scheme 121

Scheme 122

Scheme 123

Scheme 124

Scheme 125

Scheme 126

Scheme 127

Scheme 128

Scheme 129

Scheme 130

Scheme 131

Scheme 132

Scheme 133

DTC P0325: KNOCK SENSOR NO. 1 CIRCUIT OR DTC P0330: KNOCK SENSOR NO. 2 CIRCUIT

The knock sensors are fitted on the right bank and left bank of the cylinder block to detect the engine knocking. Each sensor contains a piezoelectric element which generates voltage when it becomes deformed, which occurs when the cylinder block vibrates due to the knocking. If the engine knocking occurs, the ignition timing is retarded to suppress it.

For DTC detection conditions and possible causes (Scheme 134)

Scheme 134

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For Knock sensor circuit wiring diagram, diagnosis and repair procedure (Scheme 135)& (Scheme 136). For KS harness intermediate connector(s) location (Scheme 137) For Knock sensor(s) location (Scheme 138)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 135

Scheme 136

Scheme 137

Scheme 138

DTC P0335: CRANKSHAFT POSITION SENSOR "A" CIRCUIT OR DTC P0339: CRANKSHAFT POSITION SENSOR "A" CIRCUIT INTERMITTENT

The crankshaft position sensor, which detects the engine speed and crankshaft angle signal (NE signal), has been installed on the oil pump body. The NE signal plate has 34 teeth. The NE signal sensor generates 34 signals at every engine revolution. The ECM detects the standard angle of the crankshaft based on the G signal, and the actual angle of the crankshaft and the engine speed by the NE signal.

For DTC detection conditions and possible causes (Scheme 139)

Scheme 139

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 140) Crankshaft position sensor is located at front of crankshaft, near crankshaft pulley. (Scheme 141)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For CKP and CMP sensor circuit wiring diagram (Scheme 142) For location of emission related components (Scheme 67)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For adjustments, see ON-VEHICLE ADJUSTMENTS - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 140

Scheme 141

Scheme 142

DTC P0340: CAMSHAFT POSITION SENSOR "A" CIRCUIT (BANK 1 OR SINGLE SENSOR) & DTC P0341: CAMSHAFT POSITION SENSOR "A" CIRCUIT RANGE/PERFORMANCE (SINGLE SENSOR)

The camshaft position sensor (G signal) consists of a magnet iron core and pickup coil. The G signal plate has 1 tooth on its outer circumference and is installed on the LH camshaft timing pulley. When the camshafts rotate, protrusion on the signal plate and air gap on the pickup coil change, causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil. The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34 signals at every engine revolution. The ECM detects the standard angle of the crankshaft based on the G signal, the actual angle of the crankshaft and the engine speed by the NE signal.

For DTC detection conditions and possible causes (Scheme 143)

Scheme 143

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 144) Camshaft position sensor is located behind driver's side upper timing belt cover. (Scheme 145)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For CKP and CMP sensor circuit wiring diagram (Scheme 142) For location of emission related components (Scheme 67)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For adjustments, see ON-VEHICLE ADJUSTMENTS - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 144

Scheme 145

DTC P0351, DTC P0352, DTC P0353, DTC P0354, DTC P0355, DTC P0356, DTC P0357 OR DTC P0358

Code Definition

1. DTC P0351: Ignition Coil "A" Primary/Secondary Circuit
2. DTC P0352: Ignition Coil "B" Primary/Secondary Circuit
3. DTC P0353: Ignition Coil "C" Primary/Secondary Circuit
4. DTC P0354: Ignition Coil "D" Primary/Secondary Circuit
5. DTC P0355: Ignition Coil "E" Primary/Secondary Circuit
6. DTC P0356: Ignition Coil "F" Primary/Secondary Circuit
7. DTC P0357: Ignition Coil "G" Primary/Secondary Circuit
8. DTC P0358: Ignition Coil "H" Primary/Secondary Circuit

For circuit description (Scheme 146)

Scheme 146

For DTC detection conditions and possible causes (Scheme 147)

Scheme 147

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 148)- (Scheme 150).

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For ignition coil with ignitor circuit wiring diagram (Scheme 151) For location of emission related components (Scheme 67)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 148

Scheme 149

Scheme 150

Scheme 151

For circuit description (Scheme 152)

Scheme 152

This DTC uses two-trip detection logic. For DTC detection conditions and possible causes (Scheme 153)

Scheme 153

Confirmation Engine Racing Pattern

For confirmation engine racing pattern procedure (Scheme 154)

Scheme 154

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

To aid in diagnosis of a deteriorated TWC, perform Confirmation Engine Racing Pattern Procedure first. See CONFIRMATION ENGINE RACING PATTERN .

For diagnosis and repair procedure (Scheme 155)

For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 155

DTC P0441: EVAP EMISSION CONTROL SYSTEM INCORRECT PURGE FLOW OR DTC P0446: EVAP EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT

Note. If DTCs P0441, P0446, or P0451 is output with DTCs P0442 or P0456, perform appropriate test for these DTCs first before performing test for DTCs P0442 or P0456.

The vapor pressure sensor, the VSV for the canister closed valve (CCV) and the VSV for the pressure switching valve are used to detect abnormalities in the evaporative emission control system. (Scheme 156) The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal. DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from system components, or when there is a malfunction in either the VSV for the EVAP, the VSV for the pressure switching valve, or in the vapor pressure sensor itself.

Scheme 156

For DTC detection conditions and possible causes (Scheme 157)

Scheme 157

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 158)- (Scheme 179).

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 180)- (Scheme 188).

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For EVAP system circuit wiring diagram (Scheme 189) For location of emission related components (Scheme 67)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

Scheme 168

Scheme 169

Scheme 170

Scheme 171

Scheme 172

Scheme 173

Scheme 174

Scheme 175

Scheme 176

Scheme 177

Scheme 178

Scheme 179

Scheme 180

Scheme 181

Scheme 182

Scheme 183

Scheme 184

Scheme 185

Scheme 186

Scheme 187

Scheme 188

Scheme 189

DTC P0442: EVAP EMISSION CONTROL SYSTEM LEAK DETECTED (SMALL LEAK) & DTC P0456: EVAP EMISSION CONTROL SYSTEM LEAK DETECTED (VERY SMALL LEAK)

The vapor pressure sensor, the VSV for the canister closed valve (CCV) and the VSV for the pressure switching valve are used to detect abnormalities in the evaporative emission control system. (Scheme 156) The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal. DTCs P0442 and P0456 are recorded by the ECM when evaporative emissions leak from system components, or when there is a malfunction in either the VSV for the EVAP, the VSV for the pressure switching valve, or in the vapor pressure sensor itself.

DTC is set if a leak is detected in EVAP system or vapor pressure sensor malfunctions. Possible causes are

1. Damaged, disconnected or restricted vacuum hose(s) or tubes.
2. Fuel tank cap is loose or improperly installed.
3. Defective fuel tank cap.
4. Damaged fuel tank.
5. Defective charcoal canister.
6. Vapor pressure sensor circuit is open or shorted.
7. Defective vapor pressure sensor.
8. Defective ECM.

For confirmation readiness test procedure (Scheme 190)& (Scheme 191).

Scheme 190

Scheme 191

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

Note. In order to minimize time wasted diagnosing DTCs P0442 or P0456, it is recommended to perform "Confirmation Readiness Test" first to verify EVAP system readiness status and confirmation of DTC. See TEST DRIVE CONFIRMATION .

For diagnosis and repair procedure with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 192)- (Scheme 199).

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 200)- (Scheme 208).

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For EVAP system circuit wiring diagram (Scheme 189) For location of emission related components (Scheme 67)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 192

Scheme 193

Scheme 194

Scheme 195

Scheme 196

Scheme 197

Scheme 198

Scheme 199

Scheme 200

Scheme 201

Scheme 202

Scheme 203

Scheme 204

Scheme 205

Scheme 206

Scheme 207

Scheme 208

DTC P0451, DTC P0452 OR DTC P0453

Code Definition

1. DTC P0451: EVAP Emission Control System Pressure Sensor/Switch Range/Performance
2. DTC P0452: EVAP Emission Control System Pressure Sensor/Switch Low Input
3. DTC P0453: EVAP Emission Control System Pressure Sensor/Switch High Input

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

Note. If DTCs P0441, P0446, or P0451 is output with DTCs P0442 or P0456, perform appropriate test for these DTCs first before performing test for DTCs P0442 or P0456.

Vapor pressure sensor and vapor pressure sensor Vacuum Switching Valve (VSV) are used to detect abnormalities in the EVAP system.

DTC detection conditions are

1. For DTC P0451: Vapor pressure sensor output extremely changes under conditions when vehicle speed is zero MPH and engine speed is idling. Vapor pressure sensor value is greater than or equal to opening pressure value of charcoal canister, (2 trip detection logic).
2. For DTC P0452: 10 seconds or more after engine starting condition vapor pressure sensor fixed value continues to be a fixed value or less, (2 trip detection logic).
3. For DTC P0453: 10 seconds or less after engine starting condition vapor pressure sensor fixed value continues to be a fixed value or more, (2 trip detection logic).

Possible causes are

1. Vapor pressure sensor circuit is open or shorted.
2. Defective vapor pressure sensor.
3. Defective ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 209) For step 1) and step 2) perform steps 22) and 23) in (Scheme 199) respectively.

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For EVAP system circuit wiring diagram (Scheme 189) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 209

DTC P0500: VEHICLE SPEED SENSOR "A" CIRCUIT OR DTC P0503: VEHICLE SPEED SENSOR "A" INTERMITTENT/ERRATIC/HIGH

For circuit description (Scheme 210)

Scheme 210

This DTC uses one-trip detection logic. DTC is set if there is no vehicle speed signal to ECM while vehicle is being driven and park/neutral position switch is off. Possible causes are

1. Defective vehicle speed sensor.
2. Vehicle speed sensor circuit is open or shorted.
3. Defective instrument cluster.
4. Defective ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For circuit wiring diagram, diagnosis and repair procedure (Scheme 211)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 211

DTC P0504: BRAKE SWITCH "A"/"B" CORRELATION

Circuit Description & Possible Causes

For circuit description, DTC detection conditions and possible causes (Scheme 212)

Scheme 212

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 213)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For brake switch circuit wiring diagram (Scheme 214) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For adjustments, see ON-VEHICLE ADJUSTMENTS - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 213

Scheme 214

Idle speed is controlled by Electronic Throttle Control System (ETCS). ETCS uses throttle control motor to operate throttle valve opening angle to obtain target idle speed.

This DTC uses two-trip detection logic. DTC is set when idle speed continues to vary greatly from target speed. Possible causes are

1. Defective Positive Crankcase Ventilation (PCV) valve hose or connection.
2. Air induction system malfunction.
3. Defective ETCS.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

1. Using Toyota hand-held tester or scan tool, check for any other DTCs. If only DTC P0505 exists, go to next step. If other DTCs exists, diagnose and repair those DTCs first and then retest.
2. Check for any loose or defective PCV valve hose connections. PCV valve is located at front of driver's side valve cover, below oil fill cap. If PCV valve hose connections are okay, go to next step. If PCV valve hose connections are defective, repair or replace components as necessary.
3. Ensure engine oil dipstick, oil filler cap, PCV system and all other air induction system components are intact and operating properly. For vacuum or EVAP hose routing, see «VACUUM DIAGRAMS»(ref-151982) article. If problem does not exist, go to next step. If problem exists, repair as necessary.
4. Check throttle body and components for ECTS. For testing of systems or components, see «BASIC DIAGNOSTIC PROCEDURES - V6 & V8»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-controls-basic-diagnostic-procedures-v6-v8) article or «SYSTEM & COMPONENT TESTING - V6 & V8»(/toyota/land-cruiser/100-2002-2005/remont/testing-diagnostics/#engine-controls-system-component-testing-v6-v8) article. For removal and installation of components, see «REMOVAL & INSTALLATION - V6 & V8»(ref-151984) article.

DTC P0560: SYSTEM VOLTAGE

Constant battery voltage is supplied to BATT terminal at ECM as the back-up power source.

DTC is set when open in back-up power source is detected. Possible causes are

1. Back-up power source circuit is open.
2. Defective ECM.

Note. If DTC P0560 exists, the ECM will not store any other DTCs. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For wiring diagram and diagnosis and repair procedure (Scheme 215)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For location of emission related components (Scheme 67)

Scheme 215

DTC P0604, DTC P0606, DTC P0607 OR DTC P0657

Code Definition

1. DTC P0604: Internal Control Module Random Access Memory (RAM) Error
2. DTC P0606: ECM/PCM Processor
3. DTC P0607: Control Module Performance
4. DTC P0657: Actuator Supply Voltage Circuit/Open

Electronic Throttle Control System (ETCS) uses throttle control motor to operate throttle valve. Throttle valve opening is detected by Throttle Position (TP) sensor which delivers input signals to ECM. ECM uses input signals and controls the throttle control motor to provide proper throttle valve opening in response to driving conditions. DTC is set when malfunction exists in the ECM for the ETCS. Possible cause is defective ECM.

If DTC exists, replace ECM. ECM is located behind glove box. (Scheme 64)

DTC P0617: STARTER RELAY CIRCUIT HIGH

While the engine is being cranked, battery positive voltage is applied to terminal STA of ECM.

DTC will set when vehicle speed is 12 MPH or more, engine speed is 1000 RPM or more and STA signal is ON for 20 seconds with battery voltage 10.5 volts or more. Possible causes are

1. Short in park/neutral position (PNP) switch.
2. Defective starter relay circuit.
3. Defective ignition switch.
4. Defective ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 216)

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 217)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For starter relay circuit wiring diagram (Scheme 218) For location of emission related components (Scheme 67)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For adjustments, see ON-VEHICLE ADJUSTMENTS - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 216

Scheme 217

Scheme 218

DTC P2102: THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT LOW OR DTC P2103: THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT HIGH

The throttle motor is operated by the ECM and it opens and closes the throttle valve. The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the throttle body. It provides feedback to the ECM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition. If this DTC is stored, the throttle valve is locked at a certain opening angle. Also, the whole electronically controlled throttle operation is cancelled until the system returns to normal and the ignition switch is turned OFF.

Possible causes are

1. Throttle control motor circuit is open or shorted.
2. Defective throttle control motor.
3. Defective ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 219)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For TPS circuit wiring diagram (Scheme 90) For location of emission related components (Scheme 67)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 219

The throttle motor is operated by the ECM and it opens and closes the throttle valve. The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the throttle body. And, it provides feedback to the ECM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition. If this DTC is stored, the throttle valve is locked at a certain opening angle. The whole electronically controlled throttle operation is cancelled until the system returns to normal and the ignition switch is turned OFF.

DTC will set when, ECM detects throttle control motor locks up during control of throttle control motor. Possible causes are

1. Defective throttle control motor.
2. Defective throttle body.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 220)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For TPS circuit wiring diagram (Scheme 90) For location of emission related components (Scheme 67)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 220

DTC P2118: ELECTRONIC THROTTLE CONTROL SYSTEM ACTUATOR POWER SOURCE CIRCUIT

Battery voltage is supplied to +BM circuit at ECM as the power source for the Electronic Throttle Control System (ETCS).

If this DTC is stored, the throttle valve is locked at a certain opening angle. Also, the whole electronically controlled throttle operation is cancelled until the system returns to normal and the ignition switch is turned OFF. Possible causes are

1. ETCS power source circuit is open.
2. Defective ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure (Scheme 221)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For TPS circuit wiring diagram (Scheme 90) For location of emission related components (Scheme 67)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 221

DTC P2119: THROTTLE ACTUATOR CONTROL THROTTLE BODY RANGE/PERFORMANCE

The Electric Throttle Control System (ETCS) is composed of the throttle motor to operate the throttle valve, the throttle position sensor to detect the opening angle of the throttle valve, the accelerator pedal position sensor to detect the accelerator pedal position, the ECM to control the ETCS and the one valve type throttle body. The ECM controls the throttle motor to make the throttle valve opening angle properly in response driving condition. The throttle position sensor which is mounted on the throttle body detects the opening angle of the throttle valve, and it provides feedback to the ECM to control the throttle motor. If this DTC is stored, the throttle valve is locked at a certain opening angle. The whole electronically controlled throttle operation is cancelled until the system returns to normal and the ignition switch is turned OFF.

DTC is set when throttle opening angle varies greatly from target throttle opening angle. If DTC P2119 exists, ECM will turn off the power to throttle control motor and throttle valve is closed by the return spring. When this occurs, throttle valve is controlled by throttle cable connected to accelerator pedal. Possible causes are defective throttle body or ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

Check for DTCs other than DTC P2119. If other DTCs exist, troubleshoot those first. Then, recheck. If DTC P2119 is only set, replace ECM. ECM is located behind glove box and heater duct. (Scheme 64) Using Toyota hand-held tester or scan tool, ensure DTCs are cleared from ECM. Turn ignition on and then use Toyota hand-held tester or scan tool to check for DTCs. If DTC P2119 exists, replace throttle body. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

DTC P2120, DTC P2122, DTC P2123, DTC P2125, DTC P2127, DTC P2128 OR DTC P2138

Code Definition

1. DTC P2120: Throttle/Pedal Position Sensor/Switch "D" Circuit
2. DTC P2122: Throttle/Pedal Position Sensor/Switch "D" Circuit Low Input
3. DTC P2123: Throttle/Pedal Position Sensor/Switch "D" Circuit High Input
4. DTC P2125: Throttle/Pedal Position Sensor/Switch "E" Circuit
5. DTC P2127: Throttle/Pedal Position Sensor/Switch "E" Circuit Low Input
6. DTC P2128: Throttle/Pedal Position Sensor/Switch "E" Circuit High Input
7. DTC P2138: Throttle/Pedal Position Sensor/Switch "D"/"E" Voltage Correlation

Note. If DTCs related to IAT sensor, HO2S, TP control motor and sensor, ECT sensor and VP sensor are output simultaneously, the E2 sensor ground circuit at terminal No. 28 (Brown/White wire) at ECM connector E5 may be open. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For ECM electrical connector terminal identification (Scheme 66) It may be necessary to check Brown/White wire between splice E10 and terminal No. 28 at ECM connector E5. (Scheme 76)

The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal to detect the opening angle of the accelerator pedal. Since this sensor is electronically controlled with hall elements, accurate control and reliability can be obtained. Two sensors are used to detect the accelerator position and malfunctions of the accelerator position sensor. The voltage applied to APP sensor pedal terminals VPA and VPA2 of the ECM toggles between 0-5 volts, in proportion to the opening angle of the accelerator pedal. The VPA signal indicates the actual accelerator pedal opening angle and is used for the engine control. The VPA2 signal indicates the information about the opening angle and is used for detecting a malfunction. The ECM determines the current opening angle of the accelerator pedal from these signals input from terminals VPA and VPA2. ECM controls the throttle motor based on these signals.

For DTC detection conditions and possible causes (Scheme 222)

Scheme 222

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 223)& (Scheme 224).

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 225)

For ECM location (Scheme 64) For ECM connector terminal view (Scheme 66) For APP sensor circuit wiring diagram (Scheme 226) For location of emission related components (Scheme 67)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article or SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Scheme 223

Scheme 224

Scheme 225

Scheme 226

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal to detect the opening angle of the accelerator pedal. Since this sensor is electronically controlled with hall elements, accurate control and reliability can be obtained. Two sensors are used to detect the accelerator position and malfunctions of the accelerator position sensor. The voltage applied to APP sensor pedal terminals VPA and VPA2 of the ECM toggles between 0-5 volts, in proportion to the opening angle of the accelerator pedal. The VPA signal indicates the actual accelerator pedal opening angle and is used for the engine control. The VPA2 signal indicates the information about the opening angle and is used for detecting a malfunction. The ECM determines the current opening angle of the accelerator pedal from these signals input from terminals VPA and VPA2. ECM controls the throttle motor based on these signals.

DTC is set when ECM determines voltage is out of range on VPA1 or VPA2 circuits between accelerator pedal position sensor and ECM. ECM determines the current opening angle of the accelerator pedal from these inputs and controls the throttle motor based on these signals. Possible causes are

1. Accelerator pedal position sensor circuit is open or shorted.
2. Defective accelerator pedal position sensor.
3. Defective ECM.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

If DTC P2121 exists, replace accelerator pedal position sensor. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

See also:
• BASIC DIAGNOSTIC PROCEDURES - V6 & V8
• TROUBLESHOOTING - NO CODES
• COMPUTER RELEARN PROCEDURES - TOYOTA
• SYSTEM & COMPONENT TESTING - V6 & V8
• TESTING PROCEDURE
• OBD MONITOR & DRIVE CYCLE PATTERNS
• FREEZE FRAME DATA
• RETRIEVING DIAGNOSTIC TROUBLE CODES
• CLEARING DIAGNOSTIC TROUBLE CODES
• DIAGNOSTIC TESTS
• TWO-TRIP DETECTION LOGIC
• P0031
• P0100
• P0110
• P0115
• P0116
• P0120
• P0128
• P0130
• P0133
• P0134
• P0136
• P0171
• P0230
• P0300
• P0325
• P0335
• P0340
• P0351
• P0441
• P0442
• P0451
• P0500
• P0504
• P0560
• P0604
• P0617
• P2102
• P2118
• P2119
• P2120
• CONFIRMATION ENGINE RACING PATTERN