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No start no crank 96 LS400 after bat disconnect

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  • #655596
    garrygarry
    Participant

      Hi, just got a beat up 96 LS400 and was doing some work on it today. Thought it best practice to disconnect the negative battery terminal while I was doing stuff to be safe.

      After I had finished and reconnected the battery terminal, I got this:
      https://www.youtube.com/watch?v=XNv0LOWGTks
      doesn’t crank at all. started this morning fine before I did all this.

      Tried various methods online for resetting the immobilizer with no luck. It’s worth noting that I don’t have the original key or fob, just one that works in the ignition and doors, not trunk.

      not sure if I screwed up somewhere or this is supposed to happen and there’s some simple procedure I need to follow.

    Viewing 15 replies - 1 through 15 (of 31 total)
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    • #655602
      A toyotakarlIts me
      Moderator

        Boy you are death to Lexus Electrical Systems…. LOL JK…

        I would begin by testing the battery to ensure you have at least 12.6v (and possibly get a load test)…. They do it free at most auto parts stores…

        Also ensure that the battery connections are clean and tight….

        Best of luck…

        -Karl

        #655605
        garrygarry
        Participant

          Hey Karl, yeah I really am a bane to these things.

          battery reads 12.25v…I also had a neighbor come over and we tried to jump it, no luck. terminals did have some corrosion on them, cleaned with a toothbrush to make sure it had good contact.

          given i’ve been at this all day I wouldn’t be that surprised to find out it’s kinda low on charge by this point.

          #655607
          A toyotakarlIts me
          Moderator

            The MINIMUM a battery should be is 12.6 volts…. Also, even with a jump, a car alternator is not a good charger….

            Modern cars need good voltage to work right, a low battery charge can cause all sorts of problems…

            Take the battery to a professional charger (auto parts store) and see if it can come back…. at 12.25v that is not good, you may need a new battery….

            At lower than 12.6 Volts, this chart shows how charged the battery is… Yours is only 50% charged….

            Good luck

            -Karl

            #655610
            garrygarry
            Participant

              also checked fuses, only ones that looked suspicious I took pictures of.

              http://imgur.com/VKqjjLm,CmtTrG9,XhmPSgy,qudwr0Y

              #655612
              garrygarry
              Participant

                Huh, didn’t know 12.2 was bad. Going to head to advance with a friend and get a new one or at least have the old one tested, old one is an AC delco but looks at least 4 years old.

                would having the battery at 50% charge affect their testing machine or can it still tell if the battery is good?

                #655613
                A toyotakarlIts me
                Moderator

                  Well that fuse is ugly, but still looks like the working part if it is…. Well, still working… The fuse does not look blown…

                  Those fuse assemblies are very prone to shatter easily when they get old and something hits it….. The plastic gets very brittle…

                  Ironically I just picked up a relay pulling tool that works well with those… I got sick of breaking them with normal pliers and/or and killing my hands trying to pull them out… 🙂

                  Seriously, get a real charger on that battery and see if that battery comes back… That we KNOW for sure is not within specs as it stands now….

                  -Karl

                  #655615
                  A toyotakarlIts me
                  Moderator

                    [quote=”wonderbread” post=128433]Huh, didn’t know 12.2 was bad. Going to head to advance with a friend and get a new one or at least have the old one tested, old one is an AC delco but looks at least 4 years old.

                    would having the battery at 50% charge affect their testing machine or can it still tell if the battery is good?[/quote]

                    Having a 50% charge won’t hurt their machine, but they may be able to tell you it is bad with a quick test… ALso, may take hours to bring it back… (if it can be brought back)

                    Yes, 12.2 is bad… I try to ensure people know that about batteries… Most people think 12v is good and anything above is just gravy… However it is not so…

                    Good luck!

                    -Karl

                    #655616
                    A toyotakarlIts me
                    Moderator

                      [quote=”wonderbread” post=128433]Huh, didn’t know 12.2 was bad. Going to head to advance with a friend and get a new one or at least have the old one tested, old one is an AC delco but looks at least 4 years old.

                      would having the battery at 50% charge affect their testing machine or can it still tell if the battery is good?

                      #655669
                      garrygarry
                      Participant

                        Alright, I’m gonig to make a long winded post on all that was fucked up underneath the steering wheel and how I thought of looking under there in the first place, but right now I’m tired and relieved it’s working, so I’ll just post this picture, should explain enough of what the problem was.

                        http://www.avital.com/
                        goddamn aftermarket alarms

                        Not even Lexus’ fault lol

                        #655671
                        garrygarry
                        Participant

                          also advance said the battery was k, just needed to charge for a bit.

                          #655672
                          A toyotakarlIts me
                          Moderator

                            On the plus side… You are getting really intimate with the electrical systems the LEXUS!!!!

                            Glad you got it worked out… All the best! 🙂

                            -Karl

                            #655821
                            garrygarry
                            Participant

                              Hey karl, if you’re still monitoring this thread, I’ve got another electrical issue apparently. I’ve had pretty bad random missfires since I got this car (maybe 4-5 days no), had it into a shop today because it was driving me nuts and I couldn’t figure out what it was.

                              Guy says the #4 and 6 injectors are stuck open, and the ECU is sending them a constant open signal or something of the like. Recommended replacing it.

                              Now, I literally just got home and am going to start research now but could you field some questions for me?

                              1. Will any ECU from a same year LS400 do, or is the situation more complicated than that?
                              2. was going to ask if I had found the unit underneath the steerig wheel, but a little research and googling the part number on it shows it’s something about mpx body control, whatever that is.
                              https://www.youtube.com/watch?v=I0QugZfLvsc
                              3.are the cheap (well, $65 ) rebuild ebay services like this a good idea?
                              4. is this is a common issue? I’m going off this thread http://www.clublexus.com/forums/ls400/656360-all-my-crazy-lexus-issues-solved-ecu-leaking-capacitor.html claiming it is.

                              have it pulled now, going to open it up and see if there’s anything obvious.

                              #655824
                              garrygarry
                              Participant

                                Update: confirmed bad cap on the board.

                                https://www.youtube.com/watch?v=RP62CDmLaaY
                                http://imgur.com/dfyR60A

                                current plan is to find an ECU with matching numbers (TOYOTA 89661-50303).Do I need to match the numbers below it as well? (175000-8780 12V, shown in picture).

                                #655835
                                A toyotakarlIts me
                                Moderator

                                  [quote=”wonderbread” post=128642]Hey karl, if you’re still monitoring this thread, I’ve got another electrical issue apparently. I’ve had pretty bad random missfires since I got this car (maybe 4-5 days no), had it into a shop today because it was driving me nuts and I couldn’t figure out what it was.

                                  Guy says the #4 and 6 injectors are stuck open, and the ECU is sending them a constant open signal or something of the like. Recommended replacing it.

                                  Now, I literally just got home and am going to start research now but could you field some questions for me?

                                  1. Will any ECU from a same year LS400 do, or is the situation more complicated than that?
                                  2. was going to ask if I had found the unit underneath the steerig wheel, but a little research and googling the part number on it shows it’s something about mpx body control, whatever that is.

                                  3.are the cheap (well, $65 ) rebuild ebay services like this a good idea?
                                  4. is this is a common issue? I’m going off this thread http://www.clublexus.com/forums/ls400/656360-all-my-crazy-lexus-issues-solved-ecu-leaking-capacitor.html claiming it is.

                                  have it pulled now, going to open it up and see if there’s anything obvious.[/quote]

                                  Well it looks like you have confirmed a bad cap. And yes, this was an issue with these (as you have found out)

                                  As far as Fuel injectors open all the time… Well the ECU grounds the wire to the Fuel injectors (to activate them)… If the ECU is bad, the ground could be stuck and yes… Fuel injectors on full time… 🙁

                                  Another ECU from the same year and model should be no problem… The only thing I would be concerned with is the Immobilizer. (I can’t remember how complex these are for this year). But if it does have one and it is not matched to the key then the vehicle won’t start.

                                  The Rebuild services might not be a bad idea… I personally have not used any EBAY based re-builders for electronics yet, but if their feedback was good, I might give it a try. I will probably do this for my 1999 Sierra this summer which has a bad ABS module.

                                  Lastly, Again, yes, unfortunately this was a common issue.

                                  Good luck.

                                  -Karl

                                  #655841
                                  garrygarry
                                  Participant

                                    >Another ECU from the same year and model should be no problem… The only thing I would be concerned with is the Immobilizer. (I can’t remember how complex these are for this year). But if it does have one and it is not matched to the key then the vehicle won’t start.

                                    Thanks for the warning here. I don’t think it’ll be a problem for one main reason: the car didn’t come with a toyota key when I bought it lol. owner lost the key and is using some off brand spare (that only works on the ignition and doors to make things worse). So if it’s a thing to do with a wireless keyfob, it shouldn’t be an issue.

                                    that being said I’m going to do some more research and see if there’s any info on this out there.

                                  Viewing 15 replies - 1 through 15 (of 31 total)
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