Kalkhoff Tasman impulse 2.0

ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
Hi all, I'm new to this Ebike life so forgive my terminology in my correspondence. Basically have purchased a used (and well abused) Kalkhoff Tasman Ebike, and have some questions if i may. I thought the battery was dead, but after managing to charge it fully, 5 lights lit, and showing as per the long press of the battery button. I have placed it on the bike, the small Impulse display screen says "Hello" and displays eco, sport and Power settings, along with millage, and briefly shows an outline of the battery symbol, The symbol then disappears?? despite the battery being fully charged.

I have then propped up the frame and began pedalling in order to see if the motor "Kicks In" which it doesn't, I'm guessing because the system doesn't recognise there's any charge on the display?

Also upon turning the pedalling the bike no speed is indicated either? Can anyone advise me on what i need to test this?
Does the bike need to be ridden, so it senses rider weight, effort prior to the motor "Assisting" i.e can one bench test the motor?

Any advise would be greatly appreciated.

Thanks in advance

Kirk
 

soundwave

Esteemed Pedelecer
May 23, 2015
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Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
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Hi all, I'm new to this Ebike life so forgive my terminology in my correspondence. Basically have purchased a used (and well abused) Kalkhoff Tasman Ebike, and have some questions if i may. I thought the battery was dead, but after managing to charge it fully, 5 lights lit, and showing as per the long press of the battery button. I have placed it on the bike, the small Impulse display screen says "Hello" and displays eco, sport and Power settings, along with millage, and briefly shows an outline of the battery symbol, The symbol then disappears?? despite the battery being fully charged.

I have then propped up the frame and began pedalling in order to see if the motor "Kicks In" which it doesn't, I'm guessing because the system doesn't recognise there's any charge on the display?

Also upon turning the pedalling the bike no speed is indicated either? Can anyone advise me on what i need to test this?
Does the bike need to be ridden, so it senses rider weight, effort prior to the motor "Assisting" i.e can one bench test the motor?

Any advise would be greatly appreciated.

Thanks in advance

Kirk
A few of the possibilities are:-
1) PAS sensor defective or out of adjustment - assuming you have one
2) Broken wire somewhere
3) Bad plug/socket contact
4) Fuse blown
5) one or both brake senors are in the "Braking" position
6) Other electronic failure.
If you are a good electrical DIYer, and you work most carefully, you should be able to find it.
Another possible alternative is an e-bike tester, usually under 20 UK pounds.
Though I have not yet used one, I have seen one used by a profi, it gave a great impression.
See here:-
I hope this helps you further.
Andy
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
Disregard everything in the above post. None of it applies to your bike. Unfortunately, you have to go to a Kalkhoff dealer to get a diagnosis, because you need special equipment, even then, you'll probably be lucky to find one with the knowhow and wherewithal to sort it. The motor, battery and LCD use communication and hand-shaking protocols between each other.

Probably, the motor is defective. You can get an exchange motor for about £500 from the German company in the link above. It could be just a faulty LCD, but there's no way to test it. To guarantee a fix, you'd need a new motor and LCD if you're certain that the battery is OK. A motor lasts about 1700 miles on average, but some fail remarkably quickly.

It's a shame you didn't ask before buying it. I can't recommend these bikes to anybody, which is a shame because they're great bikes when they work.
 

ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
Hi folks and thanks for your replies, So here's an update, following a few night shifts i went at it again today. I discovered the battery icon failure was due to a poor connection and once cleaned up and re-crimped now displays all the time every time.

With regards to the Motion sensor attached to the rear frame which senses the magnet attached to the spokes on the rear wheel. I attached a voltmeter to test the continuity when the magnet glides past the sensor and sure enough the circuit was closed at each pass. Here's were it got interesting though, while having the voltmeter attached a current of 1.26 volts was being generated by my tester and hey presto as i turned the wheel the speedo and odometer began to function as intended. As soon as i removed the voltmeter and the 1.26 volt supply current though, it returned to non responsive??? I've checked the other cables and there isn't any spare "Feed" cables to supply power?? Also when i did have the supply connected i then hand cranked the pedals whilst trying Eco - Sport - Power modes selected and had no joy attempting to get the motor to "kick in" and assist. Agggghhhh i feel i'm close. Any ideas anyone? Please
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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3,993
Basildon
Maybe check the connector for the speed sensor. I think you might have to drop the motor to get at it because some of the connectors are in the space between the motor and the frame. I would guess that it has a 5v supply. If no 5v on the connector, then something has probably blown inside the motor housing, so you'd have to dismantle it to check.
 

ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
Update......Thanks for your input "vfr400" I have been though the whole bike including the loom inter-frame, where there is an almost impossible to reach gear selection circuit board housed within a clear perspex retainer, All appeared fine in there. with no obvious stripped / floating or detached wires. That leads to the sealed impulse mini-LCD display so i have no way of checking that end, besides which it "Appears" to be functioning on so i would rather not risk cracking that open if i can avoid it. The rear wheel sensor doesn't have power running to it, yet clearly needs voltage to send to the LCD display in order to show real-time speed. My volt meter produced 1.26 volt which appeared to function well, i have also attached a stand alone 3.5 volt camera battery to it now and again it's happily sending speed to the display, i will try a 5 volt source tomorrow as per vfr400 comments just to see if it needs that little bit extra to activate the motor.
I have then also removed and stripped the motor to make sure that everything was appearing in order. As you can see by the attached images it did appear that all was in order, however a 4 wire connection or white, brown, green & yellow did appear it had been exposed to moisture. I stripped that corrosion off and re-attached everything. The loom was fully tested and there was continuity on it all. All bearings appeared in tact, no teeth missing, Behind the silver internal plate (with the grease covered cog) are a series of plastic cogs, not wanting to disturb these i visually inspected it and replaced the cover. There didn't appear to be any compromise to the blue protective heat sink / layer covering the circuits. every thing was put back together and tried again, alas no joy. I'm out of ideas unless anyone out there has another idea, then i may just purchase a front 500 watt hub and use it that way as the rest of the bike is in pretty good nick now I've serviced it. There is also a mystery connection tucked away in the crack location its the red connector with white-brown-green-yellow wires to it, it has a protective blanking plug, anyone know what this may be? I'm guessing some sort of service / update connector? does anyone know if the bike is raised up and the crank is hand-turned would that still activate the pedal assist? of does the bike need to be ridden before the motor would activate?
Again thanks for your input so far folks its greatly appreciated.....
 

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Gliggsy

Pedelecer
May 15, 2020
96
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Got to say I admire your spirit and tenacity for getting stuck in there, watching with baited breath and hope you crack the mighty Bosch, unfortunately the only suggestion I may make is to introduce some mechanical resistance to the drive train to ensure that torque sensing is operational
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
Did you check the hall sensor connector on the motor side? It looks like you've had some water ingress in that corner, but it's not that clear in your photo (photo 2).
 

ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
Hi Folks sorry for the delay in responding, There has been a development, Since i last wrote, i have found a chap who has some spare's for the Bosch 2.0 motor. It would appear that the torque sensor and the PCB capacitor has received some damage possibly due to water ingress prior to me getting hold of this bike. Please see dismantling images, that may be of use to someone. I've ordered a replacement PCB and new Torque sensor and will be fitting them as they arrive. I have it on good authority that the motor won't "kick in" until it senses that it's under at least 4.5 kilos of resistance (don't know how it was worked out) but given i had the frame suspended, and was peddling the thing like a man possessed, needless to say it didn't kick in. I'm still trying to work out why i can't get the speed sensor to register on the LCD when turning the wheel?

Update to follow.......
 

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ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
H
Did you check the hall sensor connector?
Hi there, So Sorry but i have no idea what a "Hall Sensor" is? my experience of E-bikes is very, very limited and i'm learning as i go please be gentle as i describe things as i understand them lol, what and where is that located? With regards to the sensor i have connected a circuit tester on continuity setting to the two available red / black wires on the sensor attached to the rear wheel frame, when i then rotate the wheel, as the magnet passes the sensor it completes the circuit and beeps. when i got the bike it was in a poor abused state with bit's missing all of which appeared to be cosmetic, the rear wheel sensor was snapped off near the crank, so i have soldered this back together.

This is where my issue arises as when connected to the multi-meter it's providing the sensor with the aforementioned 1.26 volts (generated from the multi-meter) (you mentioned it needs 5 volts?) which merrily sends a signal to the LCD and reads real time speed / distance. However once the multi-meter is disconnected power is lost and no such signal is being sent to the LCD and the speedometer does nothing despite rear wheel / magnet movement.

It clearly needs some limited voltage to function and i get this, but how much and where is it's provided from, I must say it's annoying that there Bosch treat this like a top secret invention and won't release schematic / wiring diagrams to help us poor mortals out.

If this sensor does rely on a power supply to function then i clearly have a problem, it may be a simple fix when I've replaced the PCB section of the motor as this i now realise had water ingress....or this is an issue with the LCD not sending voltage to the sensor. I have also noticed that mid-point deep in the frame there is a clear perspex retainer which houses the gear select cable and signal wires it's nigh on impossible to remove fully to inspect, but from what i can see via torchlight it appears in good non damaged condition. I have found a replacement that looks almost .... 36792
Identical, however wouldn't want to spend £20 on it and still have the same issue. Thanks for you patients and any advice you can give is greatly appreciated. I'll update as soon as i have the new PCB fitted and test...I hope it's an easy fix......to be continued
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
I explained in a post above that there's signs of water ingress in the bottom right corner. The hall sensor connector is white and has about 6 pins. It's half hurried in the grey stuff. On the other end of the lead to it is a similar connector waving about in the air. Pull it out and check it for corrosion.
 

ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
Update:......I have the parts in my possession, After finishing a nightmare night-shift that literally saw me covered in brain mater yesterday, i'm refreshed and back on "Normally people" hours and ready to install the replacement PCB and the torque sensor. If these parts don't sort then I'm at a loss and will probably just install a front wheel hub motor and make use of the frame, battery, decent hydraulic brakes and other serviceable parts I have. I'll hopefully have a good news post at the end of the day.
 

ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
Success!! parts swapped and all now appears to be working as it should, I've been for a 3 mile ride with various hills and flats, swapping around the various power settings and it appeared to function as intended. The rear speed sensor also worked perfectly. Please may i take this opportunity to thank everyone's input / assistance into this journey it is all greatly appreciated.
 

Muckypup

Just Joined
Nov 24, 2020
4
0
Hi ThePara , yours was a very interesting read with perseverance and a happy ending . I’ve an Impulse 2 Evo RS , have gone thru several motors over the past few years , tho “50” were good enough to Honour their “ 2 year guarantee “ every time , supplying a new/re-con motor , each having its own “ 2 year guarantee “ .
Now I’m out of Warranty . . .
Motor just decided to STOP with no response . I could consider water ingress as had to cycle thru a Flood the other week .
Local dealer has been good enough to supply me with a non-saleable motor ( has a Kalkhoff recognised modification - greasing issue ) “ NO WARRANTY “
Ok , to try and keep this short . . . The modified motor had Mechanical failure last night ( followed by a sorry walk home , 6 miles loaded up with shopping . . . No taxi , no phone )
Now I have two broken motors out of Warranty ( am allowed to “Diss-assemble “ )
YOU are the most experienced person I’ve come across in this Field . . .
Can you cast any tips ( even a short Tutorial ) did you require special tools ?
I’d be looking to Swap Electrics into the flood damaged motor , as I know it is Mechanically SOLID
 

ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
Hi Muckypup, No specialist tools needed to be honest, the most exotic of the tools required is going to be a pair of circlip pliars. I would start standing the bike upside down followed by the obvious of removing or loosening of the rear wheel thus freeing up the drive chain chain. Then remove the large retaining allen key bolts x 3.

Once these are removed the motor is free from it's binds now only connected by it's cables. I personally labeled these, making sure of refitting ease. Once all cabled have been disconnected, you are free to lift the motor out onto your preferred work bench.

You will need some sockets at this point to remove the retaining nylock bolts from the pedal stems. Now the hardest part, that may required some heat, you need to remove the pedal stems from the main body of the motor. I used a blowtorch, center punch and semi-hard mallet to strike the center punch, Once you have it moving they do pop off quite easy, it's just getting them going that's the hard part.

Now that you have the motor free from the pedal stems and the frame, it's simply a case of removing the allen bolts around the motor and separating the two sides allowing access to the internal torque sensor, PCB and main baring. NB: note which bolts go where as if my mind serves me correctly there are different sizes around the motor. I used a cereal packet with a crude drawing of the motor and just pierced the drawing with the bolts relevant to it's location. Replace parts as required and then re-assemble not forgetting to use a good quality baring grease on the drive cogs and Barings. Also a good quality gasket sealant is needed to create a waterproof seal once re-assembled.

Then it's just a case of revering the above and replace everything back in it's place.

Any problems please feel free to drop me a note and i'll help out where i can.

Regards

Para
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
You will need some sockets at this point to remove the retaining nylock bolts from the pedal stems. Now the hardest part, that may required some heat, you need to remove the pedal stems from the main body of the motor. I used a blowtorch, center punch and semi-hard mallet to strike the center punch, Once you have it moving they do pop off quite easy, it's just getting them going that's the hard part.
That all sounds a bit weird. Can you explain what that was all about? I never had to do anything like that to disassemble an impulse motor.

Are you talking about removing the crank arms from the square taper shaft.? If so, the proper tool is a crank extractor that you can buy for about £3. You just screw it in and it pulls the crank off.
 

ThePara

Finding my (electric) wheels
Jul 5, 2020
9
5
53
bristol
Yep that's right the crank arms. Great if you have the tool, I didn't so improvised. They need to come off otherwise I couldn't split the motor apart to extract the torque sensor. Forgive my terminology This was my first and last bike, so I wasn't familiar with the part names.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
Yep that's right the crank arms. Great if you have the tool, I didn't so improvised. They need to come off otherwise I couldn't split the motor apart to extract the torque sensor. Forgive my terminology This was my first and last bike, so I wasn't familiar with the part names.
In case you have to do it again: