2003 Toyota PriusFACTORY OEM SERVICE PROCEDURE

For All Of Vehicles: Precaution

  1. PRECAUTIONS FOR HIGH-VOLTAGE CIRCUIT INSPECTION AND SERVICE 
    1. Engineers to be engaged in inspection and servicing related to high-voltage systems should undergo special training.
    2. All the high-voltage wire harness connectors are colored orange: the HV battery and other high-voltage components are identified by the "High Voltage" caution labels. Do not carelessly touch these wires and components.
    3. Before inspecting or servicing the high-voltage system, be sure to take measures such as wearing insulated gloves and removing the service plug to prevent electrocution. Carry the removed service plug in your pocket to prevent other technicians from reinstalling it while you are servicing the vehicle.
    4. After removing the service plug, wait 5 minutes before touching any of the high-voltage connectors and terminals.
      NOTE:

      The 5 minutes are required to discharge the high-voltage condenser inside the inverter.

      5. Fig 1: Removing Service Plug
      G02829650Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Before wearing insulated gloves, make sure that they are not cracked, ruptured, torn, or damaged in any other way. Do not wear wet insulated gloves.
    6. When servicing the vehicle, do not wear a metal object like a mechanical pencil or scale that may drop accidentally and cause a short circuit.
    7. Before touching a bare high-voltage terminal, wear insulated gloves and ensure that the terminal is not charged with electricity (approx. 0 V) using an electrical tester.
      8. Fig 2: Testing Insulated Gloves
      G02829651Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    8. After disconnecting or exposing a high-voltage connector or terminal, insulate it immediately using insulation tape.
    9. The screw of a high-voltage terminal should be tightened firmly to the specified torque. Both insufficient and excessive tightening torque can cause failure.
    10. Call other engineers' attention to the vehicle which high-voltage system is being inspected or repaired by hanging a "High Voltage Operation in Progress. Do Not Touch" sign (See Fig 3).
      11. Fig 3: Precautions For Voltage Operation
      G02829653Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    11. After servicing the high-voltage system and before reinstalling the service plug, check again that you have not left a part or tool inside, that the high-voltage terminal screws are firmly tightened, and that the connectors are correctly engaged.
      12. Fig 4: Precautions For Disconnecting Or Exposing High-Voltage Connector Or Terminal
      G02829652Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. PRECAUTIONS TO BE OBSERVED WHEN INSPECTING OR SERVICING ENGINE COMPARTMENT 
    Fig 5: Precautions For Inspecting Or Servicing Engine
    G02829654Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    The PRIUS, automatically turns the engine ON and OFF when the ignition switch is set to the ON position provided that the READY light on the instrument panel is lit.

    Before inspecting or servicing the engine compartment, therefore, remove the ignition switch key.

  3. ACTIONS TO BE TAKEN WHEN BATTERIES ARE DEPLETED 
    1. Actions to be taken when the auxiliary battery is depleted
      NOTE:

      The following phenomena indicate that the auxiliary battery is depleted:

      • No display appears on the instrument panel when you turn the ignition switch to the ON position.
      • The hybrid system does not start.
      • The headlights are dark.
      • The sound from the horn is weak.
      CAUTION: Never use a quick charger.
      1. Move the shift lever to the P position, and engage the parking brake.
      2. Remove the ignition key plate from the ignition switch.
      3. Using a booster cable, connect the 12 V battery of the rescue vehicle and auxiliary battery of the stalled vehicle, as shown in Fig 6.
        Fig 6: Connecting The 12 V Battery Of The Rescue Vehicle And Auxiliary Battery Of The Stalling Vehicle
        G02829655Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. Start the engine of the rescue vehicle and run the engine at a speed slightly higher than the idling speed for 5 minutes to charge the auxiliary battery of the stalled vehicle.
      5. Turn the ignition switch of the stalled vehicle to the START position to start the hybrid system.

        If the hybrid system fails to start and the master and HV battery warning lights come on, the HV battery may have been discharged.

        Fig 7: View Of Master And HV Battery Warning Lights
        G02829656Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      6. Disconnect the booster cable in the reverse way of the connection procedure.
      CAUTION: If the auxiliary battery needs to be replaced, replace it only with a 12 V battery specially designed for the use of the PRIUS.
    2. Actions to be taken when HV battery is depleted
    CAUTION: Leaving a vehicle alone for 2 - 3 months may cause electric discharge from HV battery.
    When this happens, replace the HV battery.
  4. INSPECTION MODE 
    NOTE:
    • The PRIUS automatically stops the engine while the vehicle is stopped with the engine warmed up and battery well charged if the A/C compressor operation is not required. Therefore, even if the vehicle stops for any reason such as a check of ignition timing, the inspection mode should be activated when continuous operation of the engine is required.
    • The PRIUS has a skid control as traction control function. When the wheel speed of the front wheels exceeds that of the rear wheels, this function restrains the wheel speed of the front wheels. It is necessary to activate the inspection mode and reset the skid control when turning only the front wheels using a speedometer tester.

    Activation inspection mode (Without using a hand-held tester)

    1. Perform the following (2) through (6) within 60 sec.
    2. Turn the ignition switch ON from OFF.
    3. With the shift lever in P position, fully depress the accelerator pedal 2 times.
    4. With the shift lever in N position, fully depress the accelerator pedal 2 times.
    5. With the shift lever in P position, fully depress the accelerator pedal 2 times.
    6. Activate the inspecting mode and check that the hybrid system error warning light on the multi-center display flashes.
      Fig 8: View Of Hybrid System Error Warning Light
      G02829657Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    7. Turning the ignition switch to START starts the engine's continuous operation.

    CAUTION:
    • The idling speed in the inspection mode is approx. 1,000 rpm. The number of revolutions will increase up to 1,500 rpm if the accelerator pedal is depressed to a degree of less than 60%, and up to 2,250 rpm in a case of 60% or more.
    • If a diagnosis code is recorded when entering the inspection mode, the master warning light and the error warning light on the multi-center display is lit.
    • When the master warning light is lit during operation in the inspection mode, deactivate the inspection mode and inspect the diagnosed area.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.