MALFUNCTION INDICATOR LIGHT (MIL) INSPECTION
Note. The CHECK engine light located on instrument cluster is known as Malfunction Indicator Light (MIL). Inspect MIL to ensure it is operational and will come on if a Diagnostic Trouble Code (DTC) is set.
- Turn ignition on with engine off. MIL should come on and remain on. If MIL does not come on, check bulb circuit on instrument cluster and wiring circuit between MIL and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. See «ECM LOCATION»(ref-22529-S05611535612001010300000) .
- Start engine and ensure MIL goes off. If MIL remains on with engine running, a malfunction is detected. Proceed to «RETRIEVING DIAGNOSTIC TROUBLE CODES»(ref-22529-S14390724882001010300000) .
TESTING PROCEDURE
To ensure correct diagnosis and repair, testing should be done in the following sequence
- Record Customer Complaint: Ensure all customer complaints or observations are recorded. Test drive vehicle with customer when necessary for malfunction verification.
- Retrieve Diagnostic Trouble Codes: Connect appropriate scan tool. Retrieve codes and record any freeze-frame data (if applicable). See «RETRIEVING DIAGNOSTIC TROUBLE CODES»(ref-22529-S14390724882001010300000) .
- Clear Trouble Codes: See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-22529-S33571829712001010300000) .
- Visual Inspection: Inspect all connectors of suspect circuit or component. Ensure all connections are clean and tight.
- Confirm Symptoms & Trouble Codes: Perform road test. Determine if original symptoms are still present. Retrieve codes.
- Diagnose & Repair Diagnostic Trouble Codes: Perform diagnosis and repair procedures as necessary. See TESTS W/CODES article. If no codes are present, proceed to the TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).
- Verification Procedure: After repairs have been completed, clear trouble codes. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-22529-S33571829712001010300000) . Perform road test. Ensure no codes are present and all symptoms and/or complaints have been repaired.
RETRIEVING DIAGNOSTIC TROUBLE CODES
Note. Diagnostic Trouble Codes (DTCs) may be retrieved using Toyota scan tool or On-Board Diagnostic (OBD-II) scan tool that complies with SAE standard J-1978. Toyota scan tool or OBD-II scan tool may be operated in NORMAL mode when retrieving trouble codes. Only Toyota scan tool 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 in 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 scan tool, when ignition switch is turned from ON to ACC or OFF position or scan tool is switched from NORMAL mode to CHECK mode, all DTCs and freeze-frame data will be erased. DO NOT switch modes until all DTCs and freeze-frame data have been recorded.
CHECK Mode Code Retrieval (Toyota Scan Tool Only)
- Ensure vehicle battery is fully charged. Apply parking brake. Shift transmission/transaxle into Neutral (M/T) or Park (A/T). Turn A/C and all accessories off. Ensure throttle valve is fully closed.
- Turn ignition off. Connect scan tool to Data Link Connector (DLC) No. 3. See «DATA LINK CONNECTOR»(ref-22529-S06940378642001010300000) under INTRODUCTION. Turn ignition on with engine off. Turn scan tool on.
- Switch scan tool 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. NOTE: If ignition switch is turned from ON to ACC or OFF position, all DTCs and freeze-frame data will be erased. DO NOT switch modes until all DTCs and freeze-frame data are recorded.
- Record any DTCs and freeze-frame data displayed for system diagnosis. If driveability problem exists and no codes are present, go to TESTS W/O CODES article for diagnosis by symptom.
- If any DTCs are present, perform appropriate DTC test. See «DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION»(ref-22529-S24824537672001010300000) table. For more information on freeze-frame data, see «FREEZE-FRAME DATA»(ref-22529-S15756276732001010300000) under INTRODUCTION. For information on 2-trip detection logic codes, see «TWO-TRIP DETECTION LOGIC»(ref-22529-S16672783712001010300000) under INTRODUCTION.
- After repairs for DTC have been completed, DTC must be cleared from ECM memory. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-22529-S33571829712001010300000) . Road test vehicle to ensure all symptoms and/or complaints have been repaired.
CLEARING DIAGNOSTIC TROUBLE CODES
- After performing repairs, clear Engine Control Module (ECM) memory of all stored Diagnostic Trouble Codes (DTCs) and freeze-frame data. DTCs and freeze-frame data may be cleared by using scan tool and scan tool manufacturer's instructions. NOTE: If using Toyota scan tool, DTCs and freeze-frame data may be cleared by switching from CHECK mode to NORMAL mode or from NORMAL mode to CHECK mode.
- DTCs and freeze-frame data may also be cleared by removing EFI fuse from fuse block, located in engine compartment. DTCs and freeze-frame data may also be cleared by disconnecting negative battery cable. However, other memory functions (clock, radio, alarm, seats, etc.) will be canceled and must be reset.
Note. Not all codes listed in the following table are used on every vehicle. See appropriate TESTS W/CODES article for a table linked to the appropriate codes for specific vehicles.
| Code (1) | Description | Probable Cause |
|---|---|---|
| P0100 (2) | Mass Airflow (MAF) Sensor Circuit Malfunction | Open/Short Circuit, MAF Sensor Or ECM |
| P0101 (2) | Mass Airflow (MAF) Circuit Range/Performance Fault | MAF Sensor |
| P0105 | Manifold Absolute Pressure (MAP) Sensor Circuit Malfunction | Open/Short Circuit, MAP Sensor Or ECM |
| P0106 | Manifold Absolute Pressure (MAP) Sensor Circuit Mal Malfunction | MAP Sensor |
| P0110 | Intake Air Temperature (IAT) Sensor Circuit | Open/Short Circuit, IAT Sensor Or ECM |
| P0115 | Engine Coolant Temperature (ECT) Sensor Circuit Fault | Open/Short Circuit, ECT Sensor Or ECM |
| P0116 (2) | ECT Sensor Circuit Range/Performance Fault | ECT Sensor Or Cooling System |
| P0120 | Throttle Position (TP) Sensor Malfunction | Open/Short Circuit, TP Sensor Or ECM |
| P0121 (2) | Throttle Position (TP) Sensor Circuit Range/Performance | TP Sensor |
| P0125 | Insufficient Coolant Temperature For Closed Loop | Open/Short Circuit Or HO2S |
| P0130 (2) | (3) Heated Oxygen Sensor Circuit Malfunction | HO2S Or Fuel Trim Malfunction |
| P0133 (2) | (3) Heated Oxygen Sensor Circuit Slow Response | HO2S |
| P0135 (2) | Heated Oxygen Sensor Heater Circuit Malfunction | Open/Short In Heater Circuit, HO2S Or ECM |
| P0136 (2) | (3) Heated Oxygen Sensor Circuit Malfunction | HO2S |
| P0141 (2) | Heated Oxygen Sensor Heater Circuit Malfunction | Open/Short In Heater Circuit, HO2S Or ECM |
| P0150 (2) | Heated Oxygen Sensor Circuit Malfunction | HO2S Or Fuel Trim Malfunction |
| P0153 (2) | Heated Oxygen Sensor Circuit Slow Response | HO2S |
| P0155 (2) | Heated Oxygen Sensor Heater Circuit Malfunction | Open/Short In Heater Circuit, HO2S Or ECM |
| P0156 (2) | Heated Oxygen Sensor Circuit Malfunction | HO2S |
| P0161 (2) | Heated Oxygen Sensor Heater Circuit Malfunction | Open/Short In Heater Circuit, HO2S Or ECM |
| P0171 (2) | Fuel Trim Malfunction | Too Lean |
| P0172 (2) | Fuel Trim Malfunction | Too Rich |
| P0300 | Random Misfire Detected | Ignition, EGR, Fuel System Or Engine Mechanical |
| P0301 (2) | Cylinder No. 1 Misfire Detected | Ignition System, Fuel System Or Engine Mechanical |
| P0302 (2) | Cylinder No. 2 Misfire Detected | Ignition System, Fuel System Or Engine Mechanical |
| P0303 (2) | Cylinder No. 3 Misfire Detected | Ignition System, Fuel System Or Engine Mechanical |
| P0304 (2) | Cylinder No. 4 Misfire Detected | Ignition System, Fuel System Or Engine Mechanical |
| P0305 (2) | Cylinder No. 5 Misfire Detected | Ignition System, Fuel System Or Engine Mechanical |
| P0306 (2) | Cylinder No. 6 Misfire Detected | Ignition System, Fuel System Or Engine Mechanical |
| P0307 (2) | Cylinder No. 7 Misfire Detected | Ignition System, Fuel System Or Engine Mechanical |
| P0308 (2) | Cylinder No. 8 Misfire Detected | Ignition System, Fuel System Or Engine Mechanical |
| P0325 | Knock Sensor No. 1 Circuit Malfunction | Open/Short Circuit, Loose Sensor Or ECM |
| P0330 (2) | Knock Sensor No. 2 Circuit Malfunction | Open/Short Circuit, Loose Sensor Or ECM |
| P0335 (2) | Crankshaft Position (CKP) Sensor Circuit Malfunction | Open/Short Circuit, CKP Sensor, Starter Or ECM |
| P0336 (2) | Crankshaft Position (CKP) Sensor Circuit Range/Performance | CKP Sensor Or ECM |
| P0340 (2) | Camshaft Position (CMP) Sensor Circuit Malfunction | Open/Short Circuit, CMP Sensor Or ECM |
| P0401 (2) | Insufficient EGR Flow Detected | Open/Short EGR Circuit Or ECM |
| P0402 (2) | Excessive EGR Flow Detected | Open/Short EGR Circuit Or ECM |
| P0420 (2) | Catalyst System Efficiency Below Threshold | Catalytic Converter, Oxygen Sensor Or Circuit |
| P0430 (2) | Catalyst System Efficiency Below Threshold | Catalytic Converter, Oxygen Sensor Or Circuit |
| P0440 (2) | EVAP System Malfunction | Vapor Pressure Sensor Or Circuit, Charcoal Canister Or Faulty Vacuum Circuit |
| P0441 (2) | Incorrect EVAP Purge Flow | Open/Short Purge Control Circuit, Charcoal Canister Or Faulty Vacuum Circuit |
| P0446 (2) | EVAP Vent Control Malfunction | Open/Short VSV Circuit, Charcoal Canister Or Faulty Vacuum Circuit |
| P0450 | EVAP Pressure Sensor Malfunction | Open/Short Vapor Pressure Sensor Circuit Or ECM |
| P0451 | EVAP Pressure Sensor Range/Performance | Open/Short Vapor Pressure Sensor Circuit Or ECM |
| P0500 (2) | Vehicle Speed Sensor Malfunction | Vehicle Speed Sensor Or Circuit, Instrument Cluster Or ECM |
| P0505 (2) | Idle Control System Malfunction | IAC Valve Or Circuit Or Air Intake Hose |
| P0510 (2) | Closed Throttle Position Switch Malfunction | Closed Throttle Position Switch/Circuit Or ECM |
| P1100 (2) | Barometric Pressure Sensor Circuit Malfunction | ECM |
| P1120 | Accelerator Pedal Position (APP) Sensor Circuit Malfunction | Open/Short Circuit, APP Sensor Or ECM |
| P1121 | Accelerator Pedal Position (APP) Sensor Range/Performance | APP Sensor Or ECM |
| P1125 | Throttle Control Motor Circuit Fault | Open/Short Circuit, Throttle Control Motor Or ECM |
| P1126 | Magnetic Clutch Circuit Fault | Open/Short Circuit, Magnetic Clutch Or ECM |
| P1127 | Electronic Throttle Control System (ETCS) Fault | Open ETCS Power Circuit Or ECM |
| P1128 | Throttle Control Motor Lock Fault | Throttle Control Motor, Throttle Body Or ECM |
| P1129 | Electronic Throttle Control System (ETCS) Fault | ETCS Or ECM |
| P1130 (2) | Air/Fuel Ratio Sensor (AFS) Circuit Range/Performance | Open/Short Circuit, AFS Or ECM |
| P1133 (2) | Air/Fuel Ratio Sensor (AFS) Response Malfunction | AFS7 |
| P1135 (2) | Air/Fuel Ratio Sensor (AFS) Heater Circuit Malfunction | Open/Short Circuit, AFS Or ECM |
| P1200 (2) | Fuel Pump Relay Circuit | Open/Short Relay Circuit Or ECM |
| P1300 | Ignitor Circuit Malfunction | Ignitor Circuit To ECM, Ignitor, Coil Or ECM |
| P1305 | Ignitor Circuit Malfunction | Ignitor Circuit To ECM, Ignitor, Coil Or ECM |
| P1310 | Ignitor Circuit Malfunction | Ignitor Circuit To ECM, Ignitor, Coil Or ECM |
| P1315 | Ignitor Circuit Malfunction | Ignitor Circuit To ECM, Ignitor, Coil Or ECM |
| P1320 | Ignitor Circuit Malfunction | Ignitor Circuit To ECM, Ignitor, Coil Or ECM |
| P1325 | Ignitor Circuit Malfunction | Ignitor Circuit To ECM, Ignitor, Coil Or ECM |
| P1330 | Ignitor Circuit Malfunction | Ignitor Circuit To ECM, Ignitor, Coil Or ECM |
| P1335 | Crankshaft Position (CKP) Sensor Circuit | Open/Short CKP Sensor Circuit, CKP Sensor Or ECM |
| P1340 | Ignitor Circuit Malfunction | Ignitor Circuit To ECM, Ignitor, Coil Or ECM |
| P1345 | Variable Valve Timing (VVT) Sensor Circuit Malfunction | Open/Short VVT Sensor Circuit, VVT Sensor Or ECM |
| P1346 | Variable Valve Timing (VVT) Sensor Circuit Range/Performance | Open/Short VVT Sensor Circuit, VVT Sensor Or ECM |
| P1349 | Variable Valve Timing (VVT) System | Valve Timing, Oil Control Valve, VVT Controller Or ECM |
| P1400 | Sub-Throttle Position Sensor Malfunction | Open/Short Circuit, Sub-Throttle Position Sensor Or ECM |
| P1401 | Sub-Throttle Position Sensor Range/Performance Fault | Sub-Throttle Position Sensor |
| P1405 | Turbo Pressure Sensor Circuit Malfunction | Open/Short Circuit, Turbo Pressure Sensor Or ECM |
| P1406 | Turbo Pressure Sensor Circuit Range/Performance Fault | Turbo Pressure Sensor |
| P1410 (2) | EGR Valve Position Sensor Circuit Malfunction | Open/Short Circuit, EGR Valve Position Sensor Or ECM |
| P1411 (2) | EGR Valve Position Sensor Circuit Range/Performance | EGR Valve Position Sensor |
| P1500 | Starter Signal Circuit Malfunction | Starter Signal Circuit, Ignition Switch, Starter Relay Or ECM |
| P1511 | Boost Pressure Low Malfunction | Open/Short Circuit, Air Intake Leak/Blockage, Actuator Or ECM |
| P1512 | Boost Pressure High Malfunction | Open/Short Circuit, Actuator Or ECM |
| P1520 (2) | Stoplight Switch Signal Malfunction | Short Circuit, Stoplight Switch Or ECM |
| P1565 | Cruise Control Main Switch Circuit Malfunction | Open/Short Cruise Control Switch Circuit, Cruise Control Switch Or ECM |
| P1600 | ECM BATT Malfunction | ECM Power Source Circuit Or ECM |
| P1605 | Knock Control ECM Malfunction | ECM |
| P1630 | Traction Control System Malfunction | Open/Short Circuit, Throttle Control ECU Or ECM |
| P1633 | ECM Malfunction | ECM |
| P1645 | Body ECU Malfunction | Body ECU, A/C ECU Or Communication Bus |
| P1652 | Idle Air Control Valve Circuit Malfunction | Open/Short Circuit, Wastegate Valve VSV Or ECM |
| P1656 | Oil Control Valve Circuit Fault | Open/Short Circuit, Oil Control Valve Or ECM |
| P1658 (2) | Wastegate Valve Control Circuit Malfunction | Open/Short Circuit, Wastegate Valve VSV Or ECM |
| P1661 (2) | Exhaust Gas Control Valve Circuit Malfunction | Open/Short Circuit, Exhaust Gas Control Valve VSV Or ECM |
| P1662 (2) | Exhaust By-Pass Valve Control Circuit Malfunction | Open/Short Circuit, Exhaust By-Pass Valve VSV Or ECM |
| P1780 (2) | Park/Neutral Position Switch Malfunction | Park/Neutral Position Switch/Circuit Or ECM |
| (1) Perform appropriate DTC test under DIAGNOSTIC TESTS in appropriate TESTS W/CODES article. (2) Two-trip detection logic code. For more information, see TWO-TRIP DETECTION LOGIC under INTRODUCTION. (3) Some models are equipped with non-heated oxygen sensors. | ||
| (1) | Perform appropriate DTC test under DIAGNOSTIC TESTS in appropriate TESTS W/CODES article. |
| (2) | Two-trip detection logic code. For more information, see TWO-TRIP DETECTION LOGIC under INTRODUCTION. |
| (3) | Some models are equipped with non-heated oxygen sensors. |
DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION
TROUBLE CODE TEST DRIVE CONFIRMATION
- On certain Diagnostic Trouble Codes (DTCs), once DTC has been cleared from ECM memory, a DTC test drive confirmation test can be performed to verify repairs made and that DTC does not reset. The test drive confirmation test will duplicate the conditions required to set specified DTCs.
- 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 with proper DTC test in TESTS W/CODES article.
DLC NO. 3 INSPECTION
- If scan tool displays UNABLE TO CONNECT TO VEHICLE when scan tool is connected, try scan tool on another vehicle. If scan tool operates on another vehicle, go to next step. If scan tool does not operate on another vehicle, problem is probably with scan tool.
- Check DLC No. 3 for loose or damaged terminals. Ensure DLC No. 3 terminals are in correct position in connector. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If connector and terminals are okay, go to next step.
- Check voltage and resistance between ground and specified terminal on DLC No. 3. See «DLC NO»(ref-22529-S13521607822001010300000). 3 VOLTAGE & RESISTANCE SPECIFICATIONS table. (Scheme 38) If voltage and resistance readings are not as specified, check wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
| Terminal No. (Application) (1) | Specification |
|---|---|
| 4 (Chassis Ground) | Less Than One Ohm |
| 5 (Signal) | Less Than One Ohm |
| 16 (Battery Voltage) | 9-14 Volts |
| (1) Terminal No. 2 (Celica and RAV4) or No. 7 (all others) on DLC No. 3 provides a pulse generation during the information transmission (BUS communication) from the Engine Control Module (ECM). | |
| (1) | Terminal No. 2 (Celica and RAV4) or No. 7 (all others) on DLC No. 3 provides a pulse generation during the information transmission (BUS communication) from the Engine Control Module (ECM). |
DLC NO. 3 VOLTAGE & RESISTANCE SPECIFICATIONS