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Thread: Knock on CEL coming on, when knock sensor isn't even connected!

  1. #1
    turbo addict
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    Knock on CEL coming on, when knock sensor isn't even connected!

    LM V12.5. 87 TII wiring.

    My knock sensor is not connected to the wire. Why would the CEL come on and flash like it is detecting knocks?

  2. #2
    turbo addict
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    Quote Originally Posted by tryingbe View Post
    LM V12.5. 87 TII wiring.

    My knock sensor is not connected to the wire. Why would the CEL come on and flash like it is detecting knocks?
    Ground the wire and see if it still does it. Sometimes noise or interference will set it off.
    Ian Adams Function>Form 1990 shadow scrapped, too rusty:( 1991 Spirit R/T Scrapped, parts sold:( 1989 Turbo Caravan Daily beater with built-[I]ish [/I]​engine slowly evolving into weekend turbo beater.

  3. #3
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    Re: Knock on CEL coming on, when knock sensor isn't even connected!

    If the connector is rattling free there's a capacitance effect that can occur, dunno if you've ever had a jack plug lead hooked into an amp and tapped the end of it and heard the amp pop, well a similar thing could happen on your knock connector. Grounding across it would also stop this effect.
    DD1: '02 T&C Ltd, 3.8 AWD. DD2: '15 Versa Note SV, replacing.. DDx: '14 Versa Note SV << freshly killded :( ....... Projects: '88 Voyager 3.0, Auto with shift kit, timing advance, walker sound FX muffler on 15" pumpers wrapped in 215/65/R15 H rated Nexens.... and a '95 phord escort wagon PnP head << Both may need to go :( ..... I like 3.0s ... so??? ... stop looking at me like I've got two heads!

  4. #4
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    Re: Knock on CEL coming on, when knock sensor isn't even connected!

    My old T-top daytona would flash the CEL and Pull timing when I switched from High to Low beams on the headlights!

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