OK, so a quick post before the one about “Fixing the MCCruise control”. Remember the magical fix-itself TPS problem I mentioned last post? Well it mysteriously un-fixed itself in a rather worse fashion while sat in lane three of the A420/A34 roundabout at 06:30 in the morning! Idling beautifully at 1,250rpm one instant, a little shudder or two to get my attention and then silence …… just as the lights turned green. To be fair she fired straight up again on the button, but now the idle was barely 1,000rpm and the Capo really doesn’t like the idle that low. I got to work, went to kill the ignition and she sat sweet as can be back at 1,250rpm ….. now if there’s one thing I sure hate, it’s an intermittent fault. So rather than the Capo and I falling out, I went into work and stewed on the problem while peering out of the canteen window at the bike and sulking like an irritated school boy.
Later, I fired it up to head home and all was lovely with the world. To be honest I was more annoyed than if it was broke – broke I can fix. We got home in an uneventful ride, but again the idle was low …. 1,000~1,100rpm but stable. This was now officially a lovers tiff! I’d gone over so many possibilities in my head, but in the end gut feeling was still saying it was a faulty TPS. So that’s what I went with. Next day I dug out one of the spare TPS’s and tested it – 1.2KΩ ±10% pins A-B and 1.2KΩ ±10% thru to 2.4KΩ ±10% pins A-C with the throttle closed to wide open. The following day the swap took no more than 40 minutes going steady – tank raised and perched on top of the airbox, remove two T30H screws and the electrical connector to release the TPS …………. swap sensors and reverse everything to put it all back together, simples. Then of course the magical and most important bit ….. use TuneECU to reset the TPS. Now I noted the TPS voltage as 0.27v throttle closed and 4.08 throttle fully open – this was constant and repeatable every time – perfect. Finally, I took the bike for a nice 20 mile ride and once back secure in the yard, ticking away in the September sunshine as she sat cooling down, I cracked open a cold beer in celebration of a job that appears to be successful.
Things I learned along the way ….. in TuneECU you can see that the TPS position is sampled for 16 distinct columns in the fuel maps. Of those 16 positions, 7 are for throttle positions of <10% while the other 9 positions account for the remaining 90% of the throttle movement! So it’s fair to say it is used mostly by the ECU for small throttle openings …. primarily the 0-6% range and this when measured afterwards was where the TPS was giving erratic readings. Symptoms on the bike – well primarily erratic idle, but also poor running (mostly rich – smell) in the small throttle opening range. Crack the taps and give the old girl the reins and the Capo rode perfectly normally. Fair to say the symptoms are similar but slightly different to an air leak and of course common to both cylinders, so nothing like an ignition issue. It was more random – cold, hot, time etc. it just didn’t feel like it was a leak. Anyway, the job is done now.
After a few days of the Capo behaving itself, I dug out the Dremel and opened up the sensor to have a look at the tracks inside for a definitive answer, a small Capo autopsy if you will. Once inside, I certainly didn’t expect it to be built the way it is, I expected a simple potentiometer and wiper arm ……… in reality, it uses a plastic strip with several resistors printed onto it and a wiper arm that bridges the two large resistors (left on pic). From the look of it, one of these wipers had lost spring and was no longer making good contact with the resistor it swept over.
As of 26/09/2025 AP8124866 is available from Ultimateparts.net at £224.46 inc. VAT, but only available on back order from Fowlers (Bristol). At that price it makes sourcing one on Ebay most certainly your best option.
Yes indeed it is all over. No, not the love affair with the venerable Caponord!! The three week holiday to Spain and Yorkshire (UK Caponord rally) is over and boy do I miss it already. Throughout, the Capo ran very well with only one odd fault for a couple of days that miraculously fixed itself – now that’s my kind of fault. It started just before I left … the RPM was slightly elevated at approx. 1,500 instead of the 1,250 set in the ECU. I hooked it up to TuneECU and hit TPS Reset and it dropped instantly – all good. Then a couple of days later, on the way to the ferry at Portsmouth, I noticed it was elevated again. Over the next couple of days it seemed to fluctuate between 1,250 and 1,500 for no obvious reason – raising or lowering at will. Then it just went away and has not come back since. All very strange. My guess is that it may have been a bit of stiction in the throttle plates that freed itself up with the daily use in Spain. But I guess I’ll never really know for sure.
useful. Firstly, the front axle spoke-carrier had a rebuild with new 3D printed parts in a stronger material that looks better. Secondly, the top-box got a new 3D printed warning triangle finished with reflective tape and in the middle a 3D mounting for a 50-second Firestick (fire extinguisher) ….. all recessed into the foam lining so it doesn’t affect luggage capacity, nor add noticeable weight to the lid – a win-win! This was all topped off by a set of luggage bags from xxxx made especially for the Raid aluminium luggage. 1x large bag for the left hand pannier (main “hotel” bag), 1x large bag for the top box (bulky items and tech gear) and two half-sized bags for the right hand pannier ( secondary “hotel” bag and tool/spares bag). These were worth their weight in gold on holiday and I’m so glad I had them made – perfect!
Further to the last post about accessing the Caponord ECU, I have added a couple of new pages under the ‘Aprilia Caponord Rally-Raid / ECU’ drop-down in the menu. A further page will be written shortly I hope. Apologies if they seem to ramble somewhat, but a terrible week, a stint in hospital and some rather strong pain meds have left me a little tired and woolly-headed. But I needed to get this stuff down before I forgot it all again!
I’ve just had a fun few hours preparing the Capo for its MOT (annual inspection) and one of the issues I wanted to get around to sorting was the slightly high tick-over.
Stop the Bus (or your Caponord) and grab yer smartphones again, TuneECU has just been updated to V2.2 ………… worthy of mentioning? Oh Yes! Alaine has addressed the poor connection (cable) AND the screen freezing if you swiped it when logging issue. Now TuneECU connects to the Capo quick as you like, just as it used to. I tried it numerous times and never once had a problem – fantastic! All-in-all a positive step forward …..
Connection was the same as before and data is still slow to update – tacho and TPS seem quick enough but the side-stand takes a whopping 5 seconds to change state. Still no side-stand or Fan status indicator like the PC version. The datalog facility worked, but seems to have a bug, more on this later.
When I checked my phone this morning I noticed that the TuneECU app had updated to v1.2 overnight ……. somehow I guess I’d missed it update to v1.1! Anyway, with a few minutes to spare I hooked up to the Capo (cable & Bluetooth) and noticed that the 
A week ago I downloaded the TuneECU Android App, spent a few minutes scrolling through the screens, then sat back and waited for Mr Postman to deliver a USB3 OTG cable for the Samsung Note 3 and a Bluetooth module from Ebay.
