IU Power Re-wiring – Legal or Illegal in Singapore?

After my IU power re-wiring, my motorcycle could now rest for more than 6 weeks without starting up and the battery is still good for firing up the engine. I’m happy now. However, in the meantime, I’ve received several well-meaning advise from fellow motorcycle riders that such a modification – the re-wiring of the power of the IU to only come on when the ignition is turned on – is not allowed / illegal under the Singapore Land Transport Authority (LTA) rules.

I tried searching online to find out if there is any truth in this. But search as I might, I couldn’t find any official rule or law stating whether this modification is legal or not. LTA does publish a list of allowable and non-allowable (illegal) modifications one can perform on their private vehicle, but the IU power wiring was stated nowhere. The only “sources” (if I could even call it a proper source) that I found were forum postings of people discussing the legality of the modification. There were even some forumers who claimed that LTA informed them that the modification makes the vehicle illegal and will fail the (required) annual inspection when brought in to one of the inspection centres.

Honestly, unless the government’s goal is to be “big brother” and wants to track the vehicle 24/7 (if that is even possible with the current generation of IU units), I cannot phantom why such a re-wiring – for the purpose of conserving battery on a lightly used vehicle – would be illegal. So, not satisfied and not wanting to get into any legal trouble with the authorities, I wrote in to LTA and enquired.

Quite quickly, I received a response from them – through a phonecall. And this is what I found out:

  1. The re-wiring of the IU to only power on when the vehicle’s ignition is turned on is NOT illegal.
  2. Such a configuration WILL NOT FAIL the annual inspection required of the motorcycle. In fact, testing of the IU is not even part of the annual inspection requirement.
  3. Following point (2), it is NOT EVEN NECESSARY to have an IU unit installed onto the vehicle if you do not intend to utilise roads that have electronic road pricing active (although it will be highly inconvenient – especially when using ERP-style carparks in Singapore.)

So how then does this notion of it being an illegal or not-allowable modification come about?

The answer lies in the warranty of the unit. The IU units are manufactured by a third party manufacturer, and comes with a 5 (FIVE) year warranty. Amongst others, one of the condition for this 5-year warranty to be valid – as prescribed by the manufacturer – is that the IU must be connected directly to the battery of the vehicle.

So, if for any reasons, you need to have your IU inspected (not to be confused with the vehicle inspection), and that the wiring is performed in such a manner that it is not connected directly to the battery, this IU inspection will fail and the warranty (if any) will be disqualified. Simply means, you’d need to fork out $150+GST to buy a new unit if your existing unit is found faulty (failed IU inspection).

In summary, go ahead and make that wiring modification – it is NOT illegal. The LTA officers will not harass you, and the Traffic Police will not harass you, and you certainly will not fail your annual vehicle inspection because of this re-wiring as it is not even an inspection item.

Note, that **you will lose your warranty** by doing so though.

But then again, if I ever have to send my IU for an inspection, wiring it back to the battery will leave absolutely no trace of the modification.


35 thoughts on “IU Power Re-wiring – Legal or Illegal in Singapore?”

  1. Thats a fantastic thing to hear bro… I had exactly the same issue when my IU unit was dead and I went to STA with modified wiring… They threatened me to cancel the warranty…. Now i know what to do…. Thanks.

    1. It IS true that the manufacturer will deny warranty coverage if the wiring was modified. Anyhow, did they honour the warranty eventually?

  2. Didnt have this issue as my iu is wired to the iginition switch. Went to lta to ask them to check, in the end the fuse blow. Asking them to redo $5.35 to the battery.

    1. Curious comment….. I’m not quite sure if I understand you correctly, Alvin. You didn’t have *what* issue? Also, if you didn’t have an issue, *why* did you have to get LTA (or more correctly, the authorised inspection centre) to check? And *what* do you mean by redo $5.35 to the battery?

      1. i had this before the iu don’t light up …
        and when check they just change the fuse …
        the redo most likely they scare you that in future if the thing happen again you need to pay more so just pay 5.35 to rewire the iu to save money in the future …

        1. Yes, the fuse is one of the first things I would check if the IU fails to work. I’m not sure what that $5.35 does – is it for the rewiring service? If so, since I have the knowledge and know-how, I DIY’ed it and saved $5.35. Regardless if you did it yourself or paid for the service, as far as the IU manufacturer goes, the warranty of the unit is void if you connected it to the bike’s ignition power instead of directly to the battery.

          By the way, there is NOTHING functionally wrong with my IU unit. It still works PERFECTLY well. As mentioned, the only gripe I have is the power draw from the unit even when my bike is switched off.

          1. No worries about that .
            I had mine rewired to my liking too .
            just that when heading back to ehem to claim ehem …
            just set to their ehem ehem first before you head there …
            i had mine removed and place the new one on a bike i abuse for work and when its damage i place it back to the original bike …
            warranty still cover as long as they see its in their protocol …
            * you didn’t hear that from me

          2. How do I connect it to the ignition? I know the connection to the battery is pretty simple. Would it be the same? Is it possible to DIY this and then reconnect it to the battery during inspection if needed?

  3. Thumbs up for the myth-busting. Long has the community been haunted by legends n myths till some daring knight decided to just ask. Great work!!

    1. Hey J. I’m pretty certain that many before me have also asked LTA about their position. But I was simply frustrated with not only the lack of information available online, but also all the misinformation, that prompted me to go ask them myself and then journal it here to share with others.

  4. Can just check some query. IU has internal battery right? And the external electrical power would power up the unit, including keeping the internal battery alive? If so, would disconnecting the IU from the constant battery electrical source drain the internal battery? If it does then would it wipe out any programming or data and harm the unit? Especially if it drains the external battery at the first place, meaning it may drain out internally quite fast. Any views or commentsJ?

    1. I cannot comment on this with any certainty without knowledge of the IU circuitry design. But in conventional electronics design, devices have a small internal battery to keep time and possibly to maintain some programmable data. In the case of the IU, there’s hardly any programmable data. The ONLY input it receives is a caahcard. No buttons, no settings. Programmable data should not be confused with programming data – which should be stored in ROM and doesn’t require any power to maintain data.

  5. Actually I rerouted and bike left unstarted for a few days. Dunno whether related but IU died after. Batt reconnected to try to revive but unable to resuscitate. I dont think anyone got such experience right? BTW anyone know how to revive an IU? Once connect power source the IU goes beep n display says “ON” for a while but then went back dead. No response from the inserted cashcard.

  6. The IU is one of the main power-hungry devices on your bike while at rest, likely even worse than the bike’s theft-prevention system. The IU manufacturer is more than likely aware of this issue, but has yet to address it; there’s probably no incentive to them – why should they care care if you need to buy a new battery every year?

    For daily riders, it’s not a problem, but those that leave a bike for a few weeks, around a month or more (travel / commitments / whatever), will see the battery die often.

    For that reason, I had the IU rerouted to the ignition for this purpose, but when my IU died, was subsequently told this may void warranty.

    There is some issue with having the IU cycle on while putting a separate drain such as starting the bike which causes issues with the IU.

    The alternatives which *do* seem acceptable to the IU manufacturer are:
    1. A separate switch (but remember to turn on again before riding!)
    2. An accessible plug, visible next to the IU (which you can easily see before riding)

    Regardless, the rule of thumb seems to be to wait 10-20s to let the IU cycle on before starting the bike again.

    1. Can ask where u got the info about the 10-20s cycle on? What will happen if start the bike before the completion of the cycle? Thanks

      1. Per mechanics at the IU testing places (STA, Vicom), it’s not an issue for the bike so much as an issue for the IU. I’ve had multiple IUs fail for various reasons, and was told the IUs are fairly sensitive to voltage spikes when starting up.

        Try starting up a bike with a voltmeter attached; you’ll see a huge dip in the voltage (to the ~11V range) before it jumps to >13V with the regulator kicking in.

        Since the IU is meant to always be ‘on’, I expect that the IU is not designed to manage such spikes during its boot process.

  7. I newly brought my motorbike but my brother motorbike have IU ,and now that IU machine was exchange to my motorbike and is not yet register on new motorbike number so what i want to do

    1. go lta get the serial number on the iu unit to register at your bike .
      should you forgot to change and go thru gantry with no cashcard .
      its a long hefty process later on .

  8. The reason for manufacturer to insist on “must be wired to batt”.

    This is to ensure that the internal cr123 batts will not get drained.

    One of my bike shop have open up dead and faulty IU before. U will find 1 to 2 piece of CR123 lithium batts inside.

    I not sure what will happen when these cr123 are drained thou.

    Maybe the IU will seize to work? and just give out ERR instead of working as normal?

    1. I would then argue that this would be a very poor engineering design. Unless for the purpose of timekeeping (which draws only a minuscule amount of current), no good engineering design should include a non-rechargeable internal battery and expect the equipment to last for upwards of 5 years. If, however, it is rechargeable, then wiring it to on-off with the bike’s ignition should not matter. In any case, I have known of IU units that have been wired to turn on and off with the bike’s ignition to last for years.

    2. not really bro ,
      i never changed my spark battery since i bought it .
      my iu still works fine .
      if there’s any battery inside the unit it would had died 8 years ago too .
      it just you need to idle the bike a bit longer for each day to start up the iu .
      and when at the carpark gantry i usually rev above idling to boost up the iu so that the gantry carpark can detect my iu .
      thats what i been doing .

    1. Not trying to be rude here, but I’ll highly recommend not touching the bike’s electrical system if you’re unfamiliar with it. But if you insist on trying, all you need to do is to locate a 12V source on your bike that only comes on when the ignition is turned on. One of the most common point would be lights – either the headlight or tail light wiring.

  9. Hi, I had my bike rewired to my ignition instead of the battery after working from home for the past two years. Then, I had my IU died 3 in less than 6 months in between. What could be the issue? Prior to making at modification, and when I wasn’t working from home, my IU easily last 10 years and no issue. This is the first time I had so much problems with my IU. Any way to prevent this from happening? It’s a real pain in the ass to keep going through IUs like this.

    1. Without physical access to your vehicle, I could only make some educated guesses. Ruling out the possibly of pure ass-luck (3 dead IU’s in less than 6 months), my primary suspicion is that the way it’s wired up (via ignition-on) was probably improper / sub-optimal. For example, in one of my bikes I’ve realised that if I were to tap an “ignition-on” 12V source from either my headlights or tail-lights (some common 12V source), the IU / USB charger would act up erratically. I subsequently diagnosed it to e “dirty source” – where the DC voltage was unstable and fluctuating. Adding a relay in between and then using that relay to switch these electronic components directly to the battery solved the problem for me.

      Could your issue be similar to this too?

      1. Sounds like it. I need to talk to my mechanic to tell him what I think might be the problem. Is a relay a cheap / easy fix? I’m not keen to do it myself since I know nothing about it. I have a feeling my mechanic might not know about this issue.

      2. Cool. I hope my mechanic listens to me. Since I’m going to have to get him to re-wire, bring it down to VICOM and then back to him again. I’m really tired of this merry-go-round. Thanks for the tip!

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