Engine Control System Self-Diagnostics: Other Toyota Prius I рестайлинг

SERVICE PRECAUTIONS

The following service precautions must be followed

Scheme 310

1. Ensure ignition is off and ignition key is removed from ignition before performing any inspection or service procedure in engine compartment, as engine may automatically start and shut off when ignition is on and READY light is illuminated. READY light is displayed just above the shift lever position indicator on instrument cluster at center of instrument panel.
2. Read all service and warning labels in engine compartment before performing any procedures in engine compartment.
3. All high-voltage wire harness connectors contain Orange connectors. DO NOT touch any wiring harness that contains Orange connectors.
4. High-voltage battery and other high-voltage components may be identified by HIGH VOLTAGE caution labels on them. DO NOT touch these components.
5. If necessary to inspect or service high-voltage system, ensure ignition is off. Remove service plug and wait at least 5 minutes to ensure high voltage is fully discharged before touching any high-voltage wiring harness, connectors or components. Service plug is located on service plug assembly at driver's side front corner of trunk compartment, near high-voltage battery. (Scheme 310) Ensure service plug is stored in a location in which no one may install service plug while technician is working on the vehicle.
6. If necessary to touch any high-voltage wiring harness, connectors or components, ensure service plug is removed and battery voltage or less exists at electrical connector. Use Toyota insulated gloves when touching any high-voltage wiring harness, connectors or components. Ensure insulated gloves are dry and in good condition. Ensure that no holes exist in insulated gloves by applying air to insulated glove before touching any high-voltage wiring harness, connectors or components.
7. DO NOT wear any metal objects while working on vehicle which may accidently drop and cause a short circuit.
8. If any high-voltage wiring harness connector is disconnected, ensure terminal on wiring harness connector is wrapped with tape to prevent wiring harness connector from contacting any surface.
9. If servicing high-voltage system, place sign on roof of vehicle to indicate to other technicians that high-voltage system is being serviced.

TWO-TRIP DETECTION LOGIC

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

DATA LINK CONNECTOR

OBD-II regulations (SAE J-1962) standardizes configuration of Data Link Connector (DLC) No. 3. DLC No. 3 is located under driver's side of instrument panel, left of steering column. (Scheme 311)

Scheme 311

FREEZE FRAME DATA

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

HYBRID VEHICLE ELECTRONIC CONTROL UNIT

Hybrid Vehicle Electronic Control Unit (HV ECU) is located below carpet on floor panel, just below passenger's side of instrument panel. (Scheme 312) If HV ECU is replaced, the HV ECU must be reprogrammed for the engine immobilizer system. Engine immobilizer system may also be referred to as Hybrid Vehicle (HV) immobilizer system. For programming procedures, see HYBRID VEHICLE ELECTRONIC CONTROL UNIT PROGRAMMING under PROGRAMMING.

Scheme 312

HYBRID VEHICLE ELECTRONIC CONTROL UNIT PROGRAMMING

Note. Following procedure is for only programming the Hybrid Vehicle Electronic Control Unit (HV ECU) for engine immobilizer system operation when only HV ECU is replaced. Engine immobilizer system may also be referred to as Hybrid Vehicle (HV) immobilizer system. For programming of ignition key and transponder key Electronic Control Unit (ECU) for engine immobilizer system, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

If HV ECU is replaced, HV ECU must be programmed for engine immobilizer system operation. To program HV ECU, turn ignition on and leave ignition on for at least 30 minutes and then start the engine. This will allow transponder key ECU to transfer the information to the HV ECU to allow engine immobilizer system operation.

SUMMARY

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

DTCS P0301-P0304: CYLINDERS NO. 1-4 MISFIRE DETECTED

Note. DTC P0301 is for cylinder No. 1 misfire, DTC P0302 is for cylinder No. 2 misfire, DTC P0303 is for cylinder No. 3 misfire and DTC P0304 is for cylinder No. 4 misfire.

Note. When 2 or more DTCs for a misfiring cylinder are recorded repeatedly, but DTC P0300 is not recorded, it indicates that misfires were detected and stored into ECM memory at different times.