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replaced spark plugs hybrid warning light came on

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Hope McCloud, Aug 13, 2011.

  1. Hope McCloud

    Hope McCloud New Member

    Joined:
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    Vehicle:
    2005 Prius
    Model:
    II
    my husband just replaced the spark plugs in my 2005 prius with 174,000 miles (also replaced the right headlamp bulb). When I started the car, the PROBLEM check engine light Hybrid Warning Light came on.

    Owner's manual says take it to the Toyota dealer.

    The dealer is 50 miles away. Is it safe to drive it the 50 miles? It drove okay up and down my driveway.

    Any ideas? Happen to anyone else? I read one post which said to disconnect the battery before starting, and we did not. Could that be it?
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I suggest you take the car for a drive around the neighborhood to see if you detect any driveability problems. If none, and if all engine compartment fluids are correct, then you are probably OK driving the 50 miles. Bring your fully-charged cellphone in case you need to call for help.

    Since the check engine light came on, I suggest you ask your husband to check his work. He should have installed the correct NGK or Denso iridium spark plugs, not some cheaper substitute.

    The spark plug gaps should have been set to 1.0 - 1.1 mm. He should have torqued the spark plugs to 13 ft.-lb and the spark igniter bolts to 82 in.-lb.

    While the spark igniters were removed, they should be inspected carefully. If the plastic body shows any cracks, burn marks or rust (from water accumulating in the spark plug well) the the igniter should be replaced. Also check the low voltage and high voltage terminals and if any corrosion is seen that is another reason to replace the spark igniter.

    The wiring harness connectors to the spark igniters should be checked. When correctly inserted, you can hear a little click as the connector lock engages. If a connector is loose then the engine will misfire, causing DTC P030x (where x is the cylinder # of the misfiring cylinder) to be logged and the check engine light to appear.
     
  3. J5A

    J5A Active Member

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    Patrick, I sure hope you're still around if I ever need your expertise!
     
  4. seilerts

    seilerts Battery Curmudgeon

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    Location:
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    Vehicle:
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    Please drive to an auto parts store, have the check engine light codes read, and report back.
     
  5. Hope McCloud

    Hope McCloud New Member

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    Vehicle:
    2005 Prius
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    II
    Problem solved. Apparently it IS necessary to disconnect the battery. The only apparent problem was the need to re-set the computer, which happens when you disconnect the battery. Thanks!! to whoever wrote that post. PS Disconnecting the battery also "undid" the steps we had taken to turn off the back-up beep. Had to google it again.