Engine Control System Self Diagnostics: Diagnosis Toyota MR2 W30

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. If MIL comes on, go to next step. MIL is displayed as an engine icon located just below engine coolant temperature and fuel gauges on instrument cluster on instrument panel. If MIL does not come on, check bulb circuit on instrument cluster and wiring circuit between MIL and ECM. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. See «ENGINE CONTROL MODULE LOCATION»(ref-151967-S27808113572003010900000) .
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 «RETRIEVING DIAGNOSTIC TROUBLE CODES»(ref-151967-S39471539832003010900000) . If no DTCs exist, check wiring circuit between MIL and ECM for a short to ground. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

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»(ref-151967-S39471539832003010900000) .
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»(ref-151967-S08210266432003010900000) .
4. Visual Inspection - Inspect all electrical connectors and wiring for suspected circuit or component. Ensure all electrical 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»(ref-151967-S39471539832003010900000) .
6. Diagnose & Repair Diagnostic Trouble Codes - Perform appropriate DTC test listed under DIAGNOSTIC TESTS as necessary. For DTC descriptions, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151967-S29770677432003010900000) under DIAGNOSTIC TROUBLE CODE DEFINITIONS. If no DTCs are present and a driveability condition exists, proceed to «TROUBLESHOOTING - NO CODES»(ref-151977) 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»(ref-151967-S08210266432003010900000) . Perform road test. Ensure no DTCs exist and all symptoms and/or complaints have been repaired. Ensure no DTCs are present and all symptoms and/or complaints have been repaired.

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, 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, 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 Data Link Connector No. 3 (DLC3). see scheme 1 Turn ignition on with engine off. Turn scan tool on. Using scan tool manufacturer's instructions, check for DTCs and freeze frame data.
2. If scan tool does not display UNABLE TO CONNECT TO VEHICLE, go to next step. If scan tool displays UNABLE TO CONNECT TO VEHICLE, check DLC3. See «DATA LINK CONNECTOR INSPECTION»(ref-151967-S10040232592003010900000) 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»(ref-151977) article for diagnosis by symptom.
4. If any DTCs are present, perform appropriate DTC test under «DIAGNOSTIC TESTS»(ref-151967-S16193086972003010900000). For DTC descriptions, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151967-S29770677432003010900000) under DIAGNOSTIC TROUBLE CODE DEFINITIONS. For more information on freeze frame data, see «FREEZE FRAME DATA»(ref-151967-S32044846962003010900000). For information on two-trip detection logic DTCs, see «TWO-TRIP DETECTION LOGIC»(ref-151967-S42484599802003010900000).
5. After repairs for DTC have been completed, DTC must be cleared from ECM. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151967-S08210266432003010900000). Road test vehicle to ensure all symptoms and/or complaints have been repaired.

CHECK Mode Diagnostic Trouble Code Retrieval

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 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. Shift transmission/transaxle into Neutral. Turn A/C and all accessories off. Ensure throttle valve is fully closed. Turn ignition off. Connect hand-held tester to Data Link Connector No. 3 (DLC3). see scheme 1 Turn ignition on and then turn hand-held tester on.
2. Switch hand-held tester from NORMAL mode to CHECK mode. CHECK mode is operational if MIL on instrument cluster flashes. 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»(ref-151977) article for diagnosis by symptom.
4. If any DTCs are present, perform appropriate DTC test under «DIAGNOSTIC TESTS»(ref-151967-S16193086972003010900000). For DTC description, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151967-S29770677432003010900000) under DIAGNOSTIC TROUBLE CODE DEFINITIONS. For information on freeze frame data, see «FREEZE FRAME DATA»(ref-151967-S32044846962003010900000). For information on two-trip detection logic DTCs, see «TWO-TRIP DETECTION LOGIC»(ref-151967-S42484599802003010900000).
5. After repairs for DTC have been completed, DTC must be cleared from ECM memory. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151967-S08210266432003010900000). 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 EFI1 fuse (15-amp). EFI1 fuse 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»(ref-158393) article in GENERAL INFORMATION.

TEST DRIVE CONFIRMATION

1. On certain Diagnostic Trouble Codes (DTC), once DTC has been cleared from Engine Control Module (ECM) memory, a test drive confirmation test can be performed to verify repairs are made and that DTC does not reset. Test drive confirmation test will duplicate conditions required to set specified DTCs.
2. Test drive confirmation test lists the procedure to be performed to check that DTC does not reset. Test drive confirmation tests apply only to specific DTCs. Test drive confirmation test will be included within proper DTC test under «DIAGNOSTIC TESTS»(ref-151967-S16193086972003010900000) .

DATA LINK CONNECTOR NO. 3 INSPECTION

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 No. 3 (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 DLC3 for loose or damaged terminals. Ensure DLC3 terminals are in correct position in connector. 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. If connector and terminals are okay, go to next step. If connector or terminals are defective, repair as necessary.
3. Check voltage and resistance between ground and specified terminal on DLC3. See «DATA LINK CONNECTOR NO. 3 VOLTAGE & RESISTANCE SPECIFICATIONS»(ref-151967-S05380944872003010900000). (Scheme 57) If voltage and resistance readings are not as specified, check wiring circuit. See SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

DATA LINK CONNECTOR NO. 3 VOLTAGE & RESISTANCE SPECIFICATIONS

Scheme 57

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TESTS

Note. Before performing any diagnostic test, see SELF-DIAGNOSTIC SYSTEM for diagnostic system functions and system diagnostic procedures. For location of emission related components (Scheme 58) Also check for any related Technical Service Bulletins (TSBs).

Note. To identify circuits and wire colors referenced in testing, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. To identify ECM terminals referenced in testing, refer to illustration. (Scheme 59)

Scheme 58

Scheme 59

Diagnosis & Repair

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 an Enhanced OBD II scan tool (Scheme 60)

For diagnosis and repair procedure with OBD II scan tool (Non Enhanced) (Scheme 61)

For OCV circuit wiring diagram (Scheme 67) For location of emission related components (Scheme 58) For testing OCV valve (Scheme 68)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 60

Scheme 61

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 an Enhanced OBD II scan tool (Scheme 62)- (Scheme 63).

For diagnosis and repair procedure with OBD II scan tool (Non Enhanced) (Scheme 64)- (Scheme 66).

For OCV circuit wiring diagram (Scheme 67) For location of emission related components (Scheme 58) For testing OCV valve (Scheme 68)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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Scheme 68

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

Check valve timing. See appropriate article in ENGINES. Check for timing gears and/or chain damage. Repair if necessary. If no timing gear and/or chain damage is present, replace ECM. Engine Control Module (ECM) is located behind glove box. see scheme 7

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 69) To check HO2S heater (Bank 1 or 2 Sensor 1) resistance (Scheme 94)or (Scheme 95). To check resistance of HO2S heater (Bank 1 Sensor 2) (Scheme 102)

For HO2S circuit wiring diagram (Scheme 99) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 69

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 70)- (Scheme 71).

For MAF meter circuit wiring diagram (Scheme 72) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 70

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Scheme 72

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

If only DTC P0101 is displayed, replace MAF meter. If other DTCs are displayed, diagnose and repair those DTCs first and retest. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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 74)- (Scheme 76).

For IAT sensor circuit wiring diagram (Scheme 73) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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Scheme 76

Note. After confirming DTC P0115, use Toyota hand-held tester or scan tool to access CURRENT DATA to confirm engine coolant temperature. If ECT sensor value displayed on hand-held tester or scan tool is always -40°F (-40°C), ECT sensor circuit may be open. If ECT sensor value displayed on hand-held tester or scan tool is always 284°F (140°C), ECT sensor circuit may be shorted. 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 78)- (Scheme 80).

For ECT sensor circuit wiring diagram (Scheme 77) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 77

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Scheme 80

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 P0116 exists, go to next step. If other DTCs exist, diagnose and repair those DTCs first and retest.
2. Remove and inspect cooling system thermostat. If problem exists, replace thermostat as necessary and retest system. If problem does not exist, replace ECT sensor. Perform proper cooling system bleeding procedure when refilling cooling system. See COOLING SYSTEM BLEEDING under COOLING SYSTEM in «REMOVAL & INSTALLATION - 4-CYLINDER»(ref-151983) article.

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 81)- (Scheme 82).

For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 81

Scheme 82

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 an Enhanced OBD II scan tool (Scheme 84)- (Scheme 85).

For diagnosis and repair procedure with OBD II scan tool (Non Enhanced) (Scheme 86)

For circuit wiring diagram (Scheme 83)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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Circuit Description

Throttle Position (TP) sensor is a variable resistor which monitors throttle opening. ECM determines vehicle driving condition and adjusts air/fuel mixture accordingly.

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 any other DTCs are displayed, diagnose and repair those DTCs first and retest. If only DTC P0121 is displayed, replace TP sensor.

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.
2. If thermostat is okay, ensure proper cooling system bleeding procedure is performed when filling cooling system. See COOLING SYSTEM BLEEDING under COOLING SYSTEM in «REMOVAL & INSTALLATION - 4-CYLINDER»(ref-151983) article. Go to next step. If thermostat is defective, replace thermostat as necessary and retest system. Ensure proper cooling system bleeding procedure is performed when filling cooling system. See COOLING SYSTEM BLEEDING under COOLING SYSTEM in «REMOVAL & INSTALLATION - 4-CYLINDER»(ref-151983) article.
3. 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. For ECM location see scheme 7

For confirmation driving pattern (Scheme 87)

Scheme 87

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 88)- (Scheme 90).

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

For HO2S circuit wiring diagram (Scheme 99) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 88

Scheme 89

Scheme 90

For confirmation driving pattern (Scheme 87)

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 91)- (Scheme 93).

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

For HO2S circuit wiring diagram (Scheme 99) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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Scheme 94

Scheme 95

For confirmation driving pattern (Scheme 87)

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 96)- (Scheme 98).

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

For HO2S circuit wiring diagram (Scheme 99) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 96

Scheme 97

Scheme 98

Scheme 99

For confirmation driving pattern (Scheme 100)

Scheme 100

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 101)

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

For HO2S circuit wiring diagram (Scheme 99) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 101

Scheme 102

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 103)- (Scheme 106).

For HO2S circuit wiring diagram (Scheme 99) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 103

Scheme 104

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Scheme 106

For confirmation driving pattern (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 with Toyota Hand-held tester or an Enhanced OBD II scan tool (Scheme 108)- (Scheme 113).

For diagnosis and repair procedure with OBD II scan tool (Non Enhanced) (Scheme 114)- (Scheme 119).

For fuel injector driver circuit wiring diagram (Scheme 120) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

To identify circuits referenced in testing, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For adjustments, see ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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Scheme 120

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 121)- (Scheme 122).

For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 121

Scheme 122

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 124)

For CKP sensor circuit wiring diagram (Scheme 123) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 123

Scheme 124

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 125)

For CMP sensor circuit wiring diagram (Scheme 123) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 125

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 127)- (Scheme 129).

For circuit wiring diagram (Scheme 126) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

To identify circuits referenced in testing, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For adjustments, see ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 126

Scheme 127

Scheme 128

Scheme 129

Note. This DTC uses two-trip detection logic. 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 deteriorated catalyst, it is recommended to perform Confirmation Engine Racing Pattern while observing HO2S waveform pattern. See CONFIRMATION ENGINE RACING PATTERN .

For diagnosis and repair procedure (Scheme 130) To check HO2S heater (Bank 1 or 2 Sensor 1) resistance (Scheme 94)or (Scheme 95). To check resistance of HO2S heater (Bank 1 Sensor 2) (Scheme 102)

For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 130

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 an Enhanced OBD II scan tool (Scheme 131)- (Scheme 151).

For diagnosis and repair procedure with OBD II scan tool (Non Enhanced) (Scheme 152)- (Scheme 160).

For EVAP system circuit wiring diagram (Scheme 163) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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For confirmation readiness test procedure (Scheme 161)& (Scheme 162).

Scheme 161

Scheme 162

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 an Enhanced OBD II scan tool (Scheme 164)- (Scheme 172).

For diagnosis and repair procedure with OBD II scan tool (Non Enhanced) (Scheme 172)- (Scheme 180).

For EVAP system circuit wiring diagram (Scheme 163) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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Scheme 180

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 181) For step 1) and step 2) perform steps 22) and 23) in (Scheme 171) respectively.

For EVAP system circuit wiring diagram (Scheme 163) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 181

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 183)

For circuit wiring diagram (Scheme 182) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 182

Scheme 183

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 185)

For circuit wiring diagram (Scheme 184) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 184

Scheme 185

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 187)- (Scheme 188).

For circuit wiring diagram (Scheme 186) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

To identify circuits referenced in testing, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 186

Scheme 187

Scheme 188

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 189)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

To identify circuits referenced in testing, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For vacuum or EVAP hose routing, see VACUUM DIAGRAMS article. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For adjustments, see ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 189

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 190)

For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 190

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

Replace 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 an Enhanced OBD II scan tool (Scheme 192)

For diagnosis and repair procedure with OBD II scan tool (Non Enhanced) (Scheme 193)

For starter relay circuit wiring diagram (Scheme 191) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 191

Scheme 192

Scheme 193

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 194)

For circuit wiring diagram (Scheme 199) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 194

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

Check bus communication circuits (MPX1 and MPX2) between ECM and instrument cluster and repair as necessary. For ECM location see scheme 7 For ECM connector terminal view (Scheme 59) For circuit wiring diagram (Scheme 195) Check instrument cluster operation and repair as necessary. See appropriate GAUGES & INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. If combination meter is OK, check and replace ECM.

Scheme 195

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 196)

For identification of TCU harness connector terminals (Scheme 197)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 196

Scheme 197

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 198)

For circuit wiring diagram (Scheme 199) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 198

Scheme 199

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 200)

For location of emission related components (Scheme 58)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 200

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 201)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 201

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

Replace ECM. Clear DTCs and retest. Retrieve DTCs. If DTC P1129 is still present, replace throttle body and retest. For circuit wiring diagram (Scheme 199) For location of emission related components (Scheme 58) For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

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 an Enhanced OBD II scan tool (Scheme 202)- (Scheme 203).

For diagnosis and repair procedure with OBD II scan tool (Non Enhanced) (Scheme 204)

For APP sensor circuit wiring diagram (Scheme 205) For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 202

Scheme 203

Scheme 204

Scheme 205

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

If any other DTCs are displayed, diagnose and repair those DTCs first and retest. If only DTC P2121 is displayed, replace APP sensor.

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 206)

For location of emission related components (Scheme 58)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 59)

To identify circuits referenced in testing, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Scheme 206