Engine Control System Self Diagnostics - 1GR-FE: Diagnosis Toyota 4Runner IV

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. Check that MIL comes on and remains on. MIL is displayed as an engine icon located just below the tachometer on instrument cluster on instrument panel. If MIL comes on and remains on, go to next step. If MIL does not come on, check bulb circuit on instrument cluster and Violet wire 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. see scheme 7
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»(ref-157557-S36504400632003081500000).

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-157557-S04495409992003081500000) .
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-157557-S37145618972003081500000) .
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»(ref-157557-S04495409992003081500000) .
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-157557-S19689782572003081500000) . If no DTCs are present and a no start condition exists, proceed to «BASIC DIAGNOSTIC PROCEDURES - V6 & V8»(ref-151953) article. 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-157557-S37145618972003081500000) . Perform road test. Ensure no DTCs exist 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. Toyota hand-held tester or OBD-II scan tool may be operated in NORMAL mode when retrieving DTCs. Only Toyota hand-held tester may be used in CHECK mode 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 No. 3 (DLC3) at driver's side of instrument panel. see scheme 1 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 INSPECTION»(ref-157557-S19219757482003081500000) 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 exist, perform appropriate DTC test under «DIAGNOSTIC TESTS»(ref-157557-S14693983842003081500000). For DTC descriptions, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-157557-S19689782572003081500000). For information on freeze frame data, see «FREEZE FRAME DATA»(ref-157557-S25631561702003081500000). For information on two-trip detection logic codes, see «TWO-TRIP DETECTION LOGIC»(ref-157557-S38506578862003081500000).
5. After repairs for DTC have been completed, DTC must be cleared from Engine Control Module (ECM). See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-157557-S37145618972003081500000). Road test vehicle to ensure all symptoms and/or complaints have been repaired.

CHECK Mode Diagnostic Trouble Code Retrieval (Toyota 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 No. 3 (DLC3) at driver's side of instrument panel. see scheme 1 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»(ref-151977) article for diagnosis by symptom.
4. If any DTCs exist, perform appropriate DTC test under «DIAGNOSTIC TESTS»(ref-157557-S14693983842003081500000). For DTC descriptions, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-157557-S19689782572003081500000). For information on freeze frame data, see «FREEZE FRAME DATA»(ref-157557-S25631561702003081500000). For information on two-trip detection logic DTCs, see «TWO-TRIP DETECTION LOGIC»(ref-157557-S38506578862003081500000).
5. After repairs for DTC have been completed, DTC must be cleared from Engine Control Module (ECM). See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-157557-S37145618972003081500000). 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 fuse (20-amp). EFI 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.

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.

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 687)

Scheme 687

Diagnosis & Repair

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For circuit wiring diagram (Scheme 688)

For diagnosis and repair procedure with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 689)

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 690)

Engine Control Module (ECM) is located behind glove box. see scheme 7 For ECM connector terminal view (Scheme 687)

For location of camshaft timing OCV assembly (Scheme 752) For camshaft timing OCV assembly testing procedure (Scheme 696) 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 688

Scheme 689

Scheme 690

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair procedure with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 691)- (Scheme 693).

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 694)& (Scheme 695).

Engine Control Module (ECM) is located behind glove box. see scheme 7 For ECM connector terminal view (Scheme 687) For location of camshaft timing OCV assembly (Scheme 752) For camshaft timing OCV assembly testing procedure (Scheme 696) For camshaft timing gear and OCV component replacement procedures, see appropriate article in ENGINES. For location of camshaft timing gear (Scheme 751) 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 691

Scheme 692

Scheme 693

Scheme 694

Scheme 695

Scheme 696

Circuit Description

The crankshaft position sensor (NE signal) consists of a magnet, iron core and pickup coil. The NE signal plate (crankshaft position sensor plate) has 34 teeth and is installed on the crankshaft. The NE signal sensor generates 34 signals at every engine revolution. The ECM detects the crankshaft angle and the engine revolution based on the NE signal, and the cylinder and the angle of the VVT based on the combination of the VV and NE signal.

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For location of camshaft timing gear (Scheme 751)

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

Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For circuit wiring diagram, diagnosis and repair procedure (Scheme 697)& (Scheme 698).

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 697

Scheme 698

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For circuit wiring diagram, diagnosis and repair procedure (Scheme 699)& (Scheme 700).

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 699

Scheme 700

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, P0102 or P0103, use the hand-held tester or the OBD II scan tool to confirm the mass air flow ratio from the DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL. 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 with engine idling and at normal operating temperature, E2G circuit may be open.

For circuit wiring diagram, diagnosis and repair procedure (Scheme 701), (Scheme 702) & (Scheme 703).

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 701

Scheme 702

Scheme 703

Scheme 704

Mass Airflow (MAF) meter uses a platinum hot wire which is maintained at a constant temperature by controlling the current flow through the hot wire. Current flow is then measured as an output voltage. MAF meter may also be referred to as airflow 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 air intake hose, near air cleaner assembly and contains a Black 5-pin electrical connector. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

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

After confirming DTCs P0110, P0112 and/or P0113 use the hand-held tester or the OBD II scan tool to confirm the intake air temperature from the DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL. 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 circuit wiring diagram, diagnosis and repair procedure (Scheme 705)- (Scheme 707).

For ECM location see scheme 7 For connector views (Scheme 687)and (Scheme 704). 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 705

Scheme 706

Scheme 707

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

After confirming DTCs P0115, P0117 and/or P0118, use the hand-held tester or the OBD II scan tool to confirm the engine coolant temperature from the DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL. 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.

For circuit wiring diagram, diagnosis and repair procedure (Scheme 708)- (Scheme 710).

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 708

Scheme 709

Scheme 710

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 DTCs P0116 and/or P0125 exists, go to next step. If other DTCs exist, diagnose and repair those DTCs first and retest.
2. Remove and inspect cooling system thermostat for damage and proper operation. Thermostat is located behind thermostat housing on driver's side front of engine, just behind cooling fan. If thermostat is defective, replace thermostat. If thermostat is okay, replace ECT sensor. ECT sensor is located behind upper timing belt cover, on top of intake manifold and contains Dark Gray 2-pin electrical connector with Brown and Black/Blue wires. For removal and installation of components, see «REMOVAL & INSTALLATION - V6 & V8»(ref-151984) article.

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 with Toyota hand-held tester or Enhanced OBD II scan tool (Scheme 711)- (Scheme 713).

For diagnosis and repair procedure with generic OBD II scan tool (Scheme 713)- (Scheme 714).

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 711

Scheme 712

Scheme 713

Scheme 714

Throttle Position (TP) sensor uses 2 sensors which detect throttle opening and a malfunction of the TP sensor. TP sensor is located on throttle body and provides an input voltage of 0-5 volts to VTA and VTA2 terminals at Engine Control Module (ECM) in proportion to throttle opening. ECM uses input signals and controls the throttle control motor to provide proper throttle valve opening in response to driving conditions.

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 P0121 exists, replace TP sensor with throttle body as an assembly. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Note. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame 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 driver's side front of engine, just behind cooling fan. 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. see scheme 7

To aid in diagnosis or to confirm repair success, perform confirmation driving pattern. (Scheme 715)

Scheme 715

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 717)- (Scheme 719). For circuit wiring diagram (Scheme 716) When prompted to perform confirmation driving pattern, see TEST DRIVE CONFIRMATION.

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 716

Scheme 717

Scheme 718

Scheme 719

Note. Clear ECM of all DTCs before performing this procedure. See CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM.

1. Test drive confirmation may be performed to operate vehicle under conditions which may cause DTC to be set. When performing test drive confirmation, procedures must be performed exactly as listed or the malfunction may not be detected. If Toyota hand-held tester is available, go to next step. If Toyota hand-held tester is not available, go to step 4.
2. Connect hand-held tester to Data Link Connector No. 3 (DLC3) at driver's side of instrument panel. see scheme 1 Switch hand-held tester from NORMAL mode to CHECK mode.
3. Start engine and warm engine to normal operating temperature. Ensure all accessories are off. Drive vehicle at 38-75 MPH with engine speed of 1600-3200 RPM for 3-5 minutes. Check operation of Malfunction Indicator Light (MIL). If MIL illuminates, malfunction exists and DTC is set. If MIL does not illuminate, malfunction does not exist.
4. Start engine and warm engine to normal operating temperature. Ensure all accessories are off. Drive vehicle at 38-75 MPH with engine speed of 1600-3200 RPM for 3-5 minutes.
5. Turn ignition off. Repeat step 4 again and then check operation of Malfunction Indicator Light (MIL). If MIL illuminates, malfunction exists and DTC is set. If MIL does not illuminate, malfunction does not exist.

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 720)- (Scheme 726).

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 - 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 720

Scheme 721

Note. At this point in diagnosis, review the following list of hints while referring to (Scheme 722).

Note. In the following list, the voltage in parenthesis are as seen on OBD II scan tool. The voltages outside parenthesis are as seen on Toyota hand-held tester.

1. Whenever the output voltage of the A/F sensor remains at approximately 3.3 volts (0.66 volt) under any conditions as well as the above conditions, the A/F sensor may have an open circuit. (This will happen also when the A/F sensor heater has an open circuit). See drawing in (Scheme 722).
2. Whenever the output voltage of the A/F sensor remains at a certain value of approximately 3.8 volts (0.76 volt) or more, or 2.8 volts (0.56 volt) or less under any condition as well as the above conditions, the A/F sensor may have a short circuit. See drawing in (Scheme 722).
3. The ECM will stop fuel injection (fuel cut) during engine deceleration. This will cause a lean condition and should result in a momentary increase in A/F ratio sensor voltage.
4. The ECM must establish a closed throttle position learned value to perform fuel cut. If the battery terminal has been disconnected, the vehicle must be driven over 10 mph to allow the ECM to relearn the closed throttle position.
5. When the vehicle is driven, in the case that the output voltage of the A/F sensor is below 2.8 volts (0.56 volt) during fuel enrichment, (for example, when the vehicle tries to overtake another vehicle on a highway, the vehicle speed is suddenly increased with the accelerator pedal fully depressed), the A/F sensor is functioning normally.
6. The A/F sensor is a current output element, and therefore the current is converted into voltage inside the ECM. If measuring voltage at connectors of A/F ratio sensor or ECM, you will obtain a constant voltage. If voltage is not as specified, proceed to step 10). (Scheme 723)- (Scheme 725). If voltages are as specified, go to step 17). (Scheme 725)& (Scheme 726). When it is necessary to perform CONFIRMATION DRIVING PATTERN, see «TEST DRIVE CONFIRMATION»(ref-157557-S02637365022003081500000).

Scheme 722

Scheme 723

Scheme 724

Scheme 725

Scheme 726

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair procedure (Scheme 727)& (Scheme 728).

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 727

Scheme 728

Note. Clear ECM of all DTCs before performing this procedure. See CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM.

1. When performing test drive confirmation, procedures must be performed exactly as listed or the malfunction may not be detected. Connect Toyota hand-held tester or scan tool to Data Link Connector No. 3 (DLC3) at driver's side of instrument panel. see scheme 1 Check for any DTCs and read FREEZE FRAME data. Record DTCs and freeze frame data. If using hand-held tester, switch hand-held tester to CHECK mode.
2. Drive vehicle several times with engine speed, load and its surrounding range shown with ENGINE SPD, CALC LOAD in freeze frame data or MISFIRE RPM and MISFIRE LOAD in the data list on hand-held tester or scan tool.
3. Drive vehicle at specified engine speeds for specified amount of time. See «DRIVING PATTERN»(ref-157557-S04255967622003081500000). If using OBD II scan tool, turn ignition off after symptom is simulated the first time (1 trip detection logic), then repeat test drive again trying to get a misfire again and set DTC (2 trip detection logic). If using hand-held tester or scan tool, if a misfire is detected, a DTC will set and misfire will be indicated in freeze frame data. Be careful not to turn ignition off, as that switches the diagnostic system from check (test) mode to normal mode. All DTCs, freeze frame data, etc. would be erased. Check for misfire DTCs by monitoring DTC and freeze frame data. Record any data. Turn ignition off and wait a minimum of 5 seconds. DRIVING PATTERN Engine RPM Specified Time Idling 3 1/2 Minutes Or More 1000 3 Minutes Or More 2000 1 1/2 Minutes Or More 3000 1 Minute Or More

Note. When 2 or more DTCs for misfiring cylinder are recorded repeatedly and DTC P0300 does not exist, it indicates misfires were detected and recorded at different times. If misfire cannot be reproduced, the reason may be because vehicle was driven with a lack of fuel, improper fuel, fouled spark plug, etc. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected. If COOLANT TEMP displayed in freeze frame data is less than 176°F (80°C), there is a possibility that misfire only exists during warm-up.

Note. If oscilloscope is available, fuel injector operation on misfiring cylinder may be checked by reading the fuel injector signal waveform pattern and fuel injector duration signal waveform pattern which may be checked by connecting oscilloscope between ECM 34-pin connector E4 terminal No. 7 (E01) (White/Black wire) and fuel injector driver terminals (#10 - #60) for misfiring cylinder at ECM with engine idling. ECM is located behind glove box. see scheme 7 For ECM electrical connector terminal identification (Scheme 687) For fuel injector driver identification, see IDENTIFYING ECM FUEL INJECTOR DRIVER TERMINALS. Fuel injector signal waveform pattern and fuel injector duration signal waveform pattern should be properly displayed within proper intervals. (Scheme 738)

For circuit wiring diagram, diagnosis and repair procedure (Scheme 729)- (Scheme 737).

When it is necessary to perform TEST DRIVE CONFIRMATION pattern, see TEST DRIVE CONFIRMATION .

When ignition coil(s) and/or ignition coil(s) and ignitor circuit diagnosis is necessary, go to DTC P0351-DTC P0356: IGNITION COIL "A"-"F" PRIMARY/SECONDARY CIRCUIT . If necessary to check or replace engine timing chain and/or timing gear(s), see appropriate article in ENGINES. 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 729

Scheme 730

Scheme 731

Scheme 732

Scheme 733

Scheme 734

Scheme 735

Scheme 736

Scheme 737

Scheme 738

IDENTIFYING ECM FUEL INJECTOR DRIVER TERMINALS

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

Note. Normal mode vibration frequency of knock sensor is 6 kHz to 15 kHz. If oscilloscope is available, knock sensor No. 1 and No. 2 operation may be checked by reading knock sensor waveform patterns with engine at 4000 RPM. (Scheme 742)for proper probe placement and terminal selections.

For circuit wiring diagram, diagnosis and repair procedure (Scheme 739)- (Scheme 742). The 6-pin connector ED1 is located rear side of right bank cylinder head.

For ECM location see scheme 7 For ECM connector view (Scheme 687) Knock sensors are located on cylinder block, just below cylinder head and under intake manifold. (Scheme 743) 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 739

Scheme 740

Scheme 741

Scheme 742

Scheme 743

Perform troubleshooting DTC P0335 first. If no trouble is found, troubleshoot the engine mechanical systems. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

If an oscilloscope is available, crankshaft position sensor operation may be checked by reading crankshaft position sensor waveform pattern with engine idling. This may be done by monitoring the crankshaft position sensor signal which is referred to as the NE signal. Crankshaft position sensor waveform pattern may be checked by connecting oscilloscope between ECM 32-pin connector E6 terminals No. 25 (NE+) (Black wire) and No. 24 (NE-) (White wire). ECM is located behind glove box. see scheme 7 For ECM electrical connector terminal identification (Scheme 687) Crankshaft position sensor waveform pattern should be properly displayed. (Scheme 747)

For circuit wiring diagram, diagnosis and repair procedure (Scheme 744)& (Scheme 745). For ECM location see scheme 7 For ECM connector view (Scheme 687) For location of CKP sensor (Scheme 746) 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 744

Scheme 745

Scheme 746

Scheme 747

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

If oscilloscope is available, VVT (CMP) sensor operation may be checked by reading VVT sensor waveform pattern with engine idling. This may be done by monitoring the VVT sensor signal which is referred to as the VV1+ (R/H) and VV2+ (L/H) signal. VVT sensor waveform pattern may be checked by connecting oscilloscope between ECM 32-pin connector E6 terminals No. 27 (VV1+) (R/H) (Red wire) and No. 24 (NE-) (White wire). For VVT2+ (L/H) waveform pattern may be checked between ECM 32-pin connector E6 terminals No. 26 (VV2+) (L/H) (Yellow wire) and No. 24 (NE-) (White wire). ECM is located behind glove box. see scheme 7 For ECM electrical connector terminal identification (Scheme 687) VVT sensor waveform patterns should be properly displayed. (Scheme 747)

For diagnosis and repair procedure (Scheme 748)& (Scheme 749).

For location of VVT (CMP) sensor (Scheme 752) If necessary to replace VVT (CMP) sensor(s) (Scheme 750) For location of VVT (CMP) sensor signal plate (Scheme 751) If necessary to replace VVT (CMP) sensor signal plate, see appropriate ENGINES 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 748

Scheme 749

Scheme 750

Scheme 751

Scheme 752

Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

If oscilloscope is available, ignition coil and ignitor operation may be checked by reading IGT and IGF signal waveform pattern with engine cranking or idling. This may be done by monitoring the IGT and IGF signal waveform pattern. It may be checked by connecting oscilloscope between IGT1 - IGT6 circuit and E1, and the IGF and E1. ECM 32-pin connector E6 terminals No. 1 (-) (E1) is ECM sensor ground. IGT and IGF waveform patterns should be properly displayed. (Scheme 753)

For circuit wiring diagram, diagnosis and repair procedure (Scheme 754)- (Scheme 758).

For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 753

Scheme 754

Scheme 755

Scheme 756

Scheme 757

Scheme 758

The ECM observes the waveform of the oxygen sensor located behind the catalyst to determine whether the catalyst performance has deteriorated. If the catalyst is functioning normally, the waveform of the oxygen sensor located behind the catalyst switches back and forth between rich and lean much more slowly. When the waveform of the oxygen sensor located behind the catalyst alternates frequently between rich and lean, it indicates that catalyst performance has deteriorated. (Scheme 759)

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

To aid in diagnosing a deteriorated catalytic converter it is recommended to first perform CONFIRMATION ENGINE RACING PATTERN .

For diagnosis and repair procedure (Scheme 759)& (Scheme 760).

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 759

Scheme 760

Confirmation Readiness Test

(Scheme 761)& (Scheme 762).

Scheme 761

Scheme 762

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

Note. If procedure requires EVAP Leak Check, see EVAP LEAK CHECK .

Note. Verify with customer if fuel tank cap has been left off or not completely tightened recently. This may cause DTC to be set. Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame records engine conditions when malfunction is detected. When ENGINE RUN TIME in freeze frame data is less than 200 seconds, check vapor pressure sensor.

For diagnosis and repair with Toyota Hand-held tester or an Enhanced OBD II scan tool (Scheme 763)(Scheme 771). For diagnosis and repair with OBD II scan tool (Non Enhanced) (Scheme 775)- (Scheme 783).

For location of EVAP control system components (Scheme 772)& (Scheme 773). For EVAP Emission Control System Wiring Diagram (Scheme 774) For ECM location see scheme 7 For ECM connector terminal view (Scheme 687) 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 763

Scheme 764

Scheme 765

Scheme 766

Scheme 767

Scheme 768

Scheme 769

Scheme 770

Scheme 771

Scheme 772

Scheme 773

Scheme 774

Scheme 775

Scheme 776

Scheme 777

Scheme 778

Scheme 779

Scheme 780

Scheme 781

Scheme 782

Scheme 783

Note. These DTCs use 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. When ENGINE RUN TIME in freeze frame data is less than 200 seconds, check vapor pressure sensor.

For diagnosis and repair procedure (Scheme 784)

For a view of vapor pressure sensor (VPS) leak detection area, see inside dotted lines in see scheme 84. For EVAP emission control system wiring diagram (Scheme 774) For ECM location see scheme 7 For ECM connector terminal view (Scheme 687) 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 784

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair procedure (Scheme 785)

For ECM location see scheme 7 For ECM connector terminal view (Scheme 687) For diagnostic procedures or replacement of combination meter (instrument cluster), see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. 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 785

The signal of the stop lamp switch is used to determine whether the acceleration system is malfunctioning or not. The stop lamp switch has a duplex system (signals STP and ST1-) to memorize the malfunction when the signals of depressing and releasing the brake pedal are detected simultaneously.

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair with Toyota Hand- held tester or an Enhanced OBD II scan tool (Scheme 786)& (Scheme 787). For diagnosis and repair with generic OBD II scan tool (not Enhanced) (Scheme 788)& (Scheme 789).

For brake switch circuit wiring diagram see scheme 112 For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 786

Scheme 787

Scheme 788

Scheme 789

The idle speed is controlled by the Electric Throttle Control System (ETCS). ETCS is composed of

1. Throttle motor to operate the throttle valve.
2. Throttle position sensor to detect the opening angle of the throttle valve.
3. Accelerator pedal position sensor to detect the accelerator pedal position.
4. ECM to control the ETCS, and the one valve type throttle body.

The ECM controls the throttle motor to provide the proper throttle valve opening angle for the target idle speed.

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair procedure (Scheme 790)

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

Scheme 790

Note. If DTC P0560 appears, the ECM does not store another DTC.

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair procedure (Scheme 791)

For ECM location see scheme 7 For ECM connector view (Scheme 687)

Scheme 791

Note. If DTCs P0604, P0606, P0607 and/or P0657 exists, the ECM will not store any other DTCs. Internal ECM error. Cause is ECM. 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. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair with Toyota Hand-held tester or an Enhanced OBD II scan tool (Scheme 792) For diagnosis and repair with generic OBD II scan tool (Non Enhanced) (Scheme 794)

For diagnostic procedure on cranking holding function circuit, see CRANKING HOLDING FUNCTION CIRCUIT. PNP switch connector P1 is located right rear engine room, above R/H cylinder head cover. For starter relay circuit wiring diagram (Scheme 793) For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 792

Scheme 793

Scheme 794

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair procedure (Scheme 796)

For circuit wiring diagram (Scheme 795) For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 795

Scheme 796

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair procedure (Scheme 797)

For circuit wiring diagram (Scheme 795) For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 797

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

For diagnosis and repair (Scheme 799)

For circuit wiring diagram (Scheme 798) For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 798

Scheme 799

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

Check for DTCs. If DTCs other than DTC P2119 are set, troubleshoot them first and recheck. If only DTC P2119 is set, check throttle body with motor assembly. Disconnect the throttle body 6-pin connector. Measure the motor resistance between terminal M+ and M- (component side). (Scheme 795) Resistance should be 0.3 to 100 ohms at 68°F (20°C). If resistance is not as specified, replace throttle body with motor assembly. If resistance is as specified, replace ECM. ECM is located behind glove box. see scheme 7 Using Toyota hand-held tester or scan tool, ensure DTCs are cleared from ECM. Turn ignition on and then use 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.

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

After confirming DTCs P2120, P2122, P2123, P2125, P2127, P2128 and P2138, use the hand-held tester or the OBD II scan tool to confirm the accelerator pedal position sensor output voltage. see scheme 127

For diagnosis and repair with Toyota Hand-held tester or an Enhanced OBD II scan tool (Scheme 800)& (Scheme 801). For diagnosis and repair with generic OBD II scan tool (not Enhanced) (Scheme 803)& (Scheme 804).

For APP sensor wiring diagram (Scheme 802) For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 800

Scheme 801

Scheme 802

Scheme 803

Scheme 804

Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. After confirming DTC P2121, use the hand-held tester or the OBD II scan tool to confirm the accelerator pedal position sensor output voltage. see scheme 127

For diagnosis and repair with Toyota Hand-held tester or an Enhanced OBD II scan tool (Scheme 805) For diagnosis and repair with generic OBD II scan tool (Non Enhanced) (Scheme 806)

For APP sensor wiring diagram (Scheme 802) For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 805

Scheme 806

1. Test drive confirmation may be performed to operate vehicle under conditions which may cause DTC to be set. When performing test drive confirmation, procedures must be performed exactly as listed or the malfunction may not be detected. If Toyota hand-held tester is available, go to next step. If Toyota hand-held tester is not available, go to step 4.
2. Connect hand-held tester to Data Link Connector No. 3 (DLC3) at driver's side of instrument panel. see scheme 1 Switch hand-held tester from NORMAL mode to CHECK mode.
3. Start engine and warm engine to normal operating temperature. Ensure all accessories are off. Drive vehicle at 38-75 MPH with engine speed of 1600-3200 RPM for 3-5 minutes. Check operation of Malfunction Indicator Light (MIL). If MIL illuminates, malfunction exists and DTC is set. If MIL does not illuminate, malfunction does not exist.
4. Start engine and warm engine to normal operating temperature. Ensure all accessories are off. Drive vehicle at 38-75 MPH with engine speed of 1600-3200 RPM for 3-5 minutes.
5. Turn ignition off. Repeat step 4 again and then check operation of Malfunction Indicator Light (MIL). If MIL illuminates, malfunction exists and DTC is set. If MIL does not illuminate, malfunction does not exist.

Note. After confirming DTCs P2195, P2196, P2197 and/or P2198, use Toyota hand-held tester or scan tool to access DATA LIST to read output voltage for A/F sensor. Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For preliminary inspection with Toyota Hand-held tester or an Enhanced OBD II scan tool (Scheme 808) For diagnosis and repair procedure (Scheme 809)- (Scheme 813). When instructed to "Perform Confirmation Driving Pattern", see TEST DRIVE CONFIRMATION.

For A/F sensor circuit wiring diagram (Scheme 807) For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 807

Scheme 808

Scheme 809

Scheme 810

Scheme 811

Scheme 812

Scheme 813

Note. Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected. After confirming DTCs P2237 through P2242 and/or P2251 through P2256, use Toyota hand-held tester or scan tool to access DATA LIST to read output voltage for A/F sensor.

For preliminary inspection with Toyota Hand-held tester or an Enhanced OBD II scan tool (Scheme 808) For diagnosis and repair procedure (Scheme 814)

For A/F sensor circuit wiring diagram (Scheme 807) For ECM location see scheme 7 For ECM connector view (Scheme 687) 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 814

DTC P2A00: A/F SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 1) OR DTC P2A03: A/F SENSOR CIRCUIT SLOW RESPONSE (BANK 2 SENSOR 1)

Note. This DTC may be caused by the vehicle running out of fuel.

Note. DTC P2A00 or P2A03 may be also detected when the air fuel ratio is stuck rich or lean. A low A/F sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich. A high A/F sensor voltage could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.

This DTC is recorded when A/F sensor has a malfunction, although the caption is oxygen sensor. Refer to CIRCUIT DESCRIPTION under DTCs P2195, P2196, P2197 & P2198: OXYGEN SENSOR SIGNAL STUCK (BANK 1 &/OR 2 SENSOR 1).

Note. Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected.

The procedure here is the same as for DTCs P2195 through P2198. The only difference will be when asked to check for DTCs throughout procedure, check for DTCs P2A00 and P2A03. For diagnosis and repair procedure, see DIAGNOSIS & REPAIR under DTCs P2195, P2196, P2197 & P2198: OXYGEN SENSOR SIGNAL STUCK (BANK 1 &/OR 2 SENSOR 1).

The system detects the ignition (IG) switch starting signal (STSW signal) and then supplies current to the starter until the ECM determines that the engine has started successfully. The purpose of this function is to reduce holding time of the ignition key.

Note. PNP switch connector P1 is located right rear engine room, above R/H cylinder head cover.

For diagnosis and repair with Toyota Hand-held tester or an Enhanced OBD II scan tool (Scheme 816)- (Scheme 819). For diagnosis and repair with generic OBD II scan tool (not Enhanced) (Scheme 820)- (Scheme 823).

For starter relay circuit wiring diagram (Scheme 793)& (Scheme 815). For ECM location see scheme 7 For ECM connector view (Scheme 687)

Scheme 815

Scheme 816

Scheme 817

Scheme 818

Scheme 819

Scheme 820

Scheme 821

Scheme 822

Scheme 823