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This car didn't last long either! Electrical Problem Advice (ECU?? Wiring?? No idea!)

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  • This car didn't last long either! Electrical Problem Advice (ECU?? Wiring?? No idea!)

    Hi,

    So I joined this forum back when I had an insignia which only lasted a month and ended up needing over 800 in repairs. I bought a lemon. Well it appears that I have done the same thing again and bought another lemon, this time not an insignia.

    I bought a 2006 1.6l Ford Focus Estate (pictured at the bottom of this thread). Only had it a few weeks before all the below issues occured at the very same time. As they all occured at the same time, it is clear to me that a common fault caused it. I did find a solution that disconnecting the negative terminal of the battery fixed the issue but 4 weeks later (and 800miles) after the intitial issue the issue returned in the exact same way as described below.



    I first noticed anything was wrong with the car when I went to open it one morning and the central locking on the remote didn't work. I assumed the key remote had a bad battery. I used the key to gain entry (where all the doors tend to open due to central locking, but only the drivers side opened). At this point, having not used the remote to open the car, a buzzer should sound as a warning before the alarm goes off. However, this did not occur. The same buzzer should sound when the lights are left on in the car, but this also did not occur. I then discovered that far more was not working:
    • Central locking not functional
    • Warning buzzer/chime does not sound
    • Indicators not functional
    • Hazards not functional
    • Handbrake light remains on when handbrake is released
    • Cabin blower motors not functional (ac light does come on tho when it is turned on, just no fan spin)
    • Heated front and rear windscreens don't work
    • High beams not functional
    • Intermittent wipers not functional. Other wiper speeds were functional, but when turned off, they did not return to down position
    • Dipped headlights are on even though they are turned off at the switch only (with the engine running)
    • Exterior temperature sensor reading can't be detected
    • Can't open any of the door locks from inside the car



    Although no engine light was on, I did a code read and one code was detected relating to the position of the throttle body not being able to be communicated with the ECU.



    I've heard some people say it is likely an ECU fault. I've also read that rather than an ECU fault, it could be the wires connected to the ECU having some kind of fault leading to communication issues.

    Apart from these issues, the car seems to run and drive supberb (even before carrying out the "fix").



    Anyone got any advice on how to track down the actual culprit. I only bought the car for 1000 so paying a garage to diagnose it would probably cost half that plus more on top for the actual repair. Technically I did buy it off a trader, but he's ignoring my messages so imagine he knew about the fault. I guess thats the risk you take buying old cheap cars. Still annoying tho!!! I do have videos/photos of some of the above-mentioned issues if people would like to see. Currently the car is working as it should after doing the neg terminal trick, but it clearly will return.



    Thanks in advance.



  • #2
    Your consumer rights are for 6 months as long as you can prove the fault was there before purchasing.
    Electrical gremlins are worse than machinical.
    But it seems to me like BCM trouble.
    And by taking the lead off the battery you are re-setting the BCM .
    Look for water ingress for a start .
    Check all main earth's .plugs on BCM ( corroded bent pins etc )
    And take it from there .

    Sent from my Pixel 6 using Tapatalk



    .K.M.P.C.U
    YEEEEEEEEHAAAAAAAAA

    Comment


    • #3
      Originally posted by lizzard-t View Post
      Your consumer rights are for 6 months as long as you can prove the fault was there before purchasing.
      Electrical gremlins are worse than machinical.
      But it seems to me like BCM trouble.
      And by taking the lead off the battery you are re-setting the BCM .
      Look for water ingress for a start .
      Check all main earth's .plugs on BCM ( corroded bent pins etc )
      And take it from there .

      Sent from my Pixel 6 using Tapatalk
      I'll have to figure out where the BCM is first!! I imagine it's behind the glove box.

      I'm aware of the consumer rights act but the problems I face are that the seller is ignoring me, it was sold with a 12month MOT demonstrating that the indicators and other functions work and if I was to use a small claims court or similar, the value of the car is just not high enough to make the time spent worth it. As I've discovered disonnecting the negative terminal fixes it for a short period of time but there is no way I can really prove that the seller did this.

      I will look for water now, but it seems dry enough.

      Comment


      • #4
        I don't think this amount of corrosion is enough to be causing the issues, but who knows. Now I know what the wirings like, I will find a diagram to check resistance of earths.







        Comment


        • #5
          You have got to start somewhere and yes anything slightly green or something off colour is corrosion and with thease modern cars electronics it requires 100% anything less and it will throw a major wobbly

          Sent from my Pixel 6 using Tapatalk



          .K.M.P.C.U
          YEEEEEEEEHAAAAAAAAA

          Comment


          • #6
            Originally posted by lizzard-t View Post
            You have got to start somewhere and yes anything slightly green or something off colour is corrosion and with thease modern cars electronics it requires 100% anything less and it will throw a major wobbly

            Sent from my Pixel 6 using Tapatalk
            "Modern car". It's like 16 years old.
            Water probably got into the BCM as well if water tracked down the wires. Considering its intermitent, I might just clean those connectors and cross my fingers. But it likely needs a BCM which I can't program. So sounds expensive anyway.

            Comment


            • #7
              Those connectors definitely need cleaning up. I would try some contact cleaner and an old toothbrush or similar but take care around the pins as you don't want to bend them. The ecu is measuring small changes in voltage and any corrosion will affect what the ecu senses. Also, ensure the battery is fully charged.

              Start with the simple/cheap stuff before considering the bcm.

              If the trader is not responding, you could issue a money claim online and its the trader who needs to prove the fault wasn't there during your first 6 months with the car. I accept its hassle you may not want.

              Comment


              • #8
                Originally posted by Mudster View Post
                Those connectors definitely need cleaning up. I would try some contact cleaner and an old toothbrush or similar but take care around the pins as you don't want to bend them. The ecu is measuring small changes in voltage and any corrosion will affect what the ecu senses. Also, ensure the battery is fully charged.

                Start with the simple/cheap stuff before considering the bcm.

                If the trader is not responding, you could issue a money claim online and its the trader who needs to prove the fault wasn't there during your first 6 months with the car. I accept its hassle you may not want.
                Turns out that corrision is on the GEM (the GEM was replaced by a BCM in newer models and it does the same job from what I can tell). The pins on the connectors go straight onto the circuit board so I cleaned them up a bit but the GEM/BCM might already be damaged. It appears to be a common fault on these fords where the screen wash pump leaks and water traces down the wire. We'll see if the issue returns. However when the fault occurs, the computer needs resetting to make it functional again which makes me think the board is damaged. If it was just the connectors then I would've thought it would be far more intermitant rather than persist when it occurs. Only time will tell. A replacement is only about 50 from what I gather.

                Honestly, it was a 1000 car so I'm not sure I can be bothered with the hassle if the problem doesn't happen that frequently. He did say he took it in as part ex so it might be that he wasn't even aware of this issue as he only had it a short time.

                Comment

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