HOW TO: F4i Speed sensor swap
 

This is a HOWTO for changing the vehicle speed sensor (VSS) on a CBR 600 F4i (UK F1/2/FS1/FS2). The procedure is the same for removing, cleaning and checking the speed sensor before replacing it, so I will quickly go through the checks to do this also. This is a 2 beers job and start to finish shouldn’t take more than 2 hours; a mate to help you is useful but not essential. I also havent quite figured out how to embed photos yet, will change this if/when I do :icon_doh:.

In short: my speedo doesn’t work for the first 10-15 minutes of each ride then it magically jumps back into life. This is accompanied by an FI light fault with code 11 (speed sensor/wiring fault) and seems to be very common on these bikes. I sometimes get about 30secs of a working speedo at the beginning of my ride.

You will need:

New speed sensor (if replacing)
Contact cleaner and multimeter if checking/cleaning
Socket wrench
Set of sockets (a deep 10mm socket or a 10mm socket with a short extender will help)
6 inch or longer (approx) socket extension
Socket universal joint or a flexible socket extension
Set of allen keys/allen bits
Set of screwdrivers
Ratchet strap (optional)
Small file/piece of sandpaper




1) Take off your seat; it makes sense to also disconnect your battery at this point – just unscrew the negative (black wire) and put something over the end to stop it touching the battery. (pic 1)


Attachment 56335

2) Remove the left fairing panel and undo the bolts holding the ram air covers to the tank (pic 2)


Attachment 56336
3) Undo the four bolts holding on the tank (two holding the seat hook and two at the top) and place a coat or towel underneath the back end of the tank (where the tank rests on the subframe by the battery) to prevent the paint from chipping as the tank is raised (red arrows) – (pic 3)

Attachment 56337

4) (pic 4)
Attachment 56338

5) Remove the rubbers, washers and metal inserts from the front bolt holes (pic 5)

Attachment 56339

6) And thread your ratchet strap/rope through the holes (pic 6)

Attachment 56329
7) Loop the other end of the strap through the rear hand rail or part of the rear subframe and use it to secure the tank upright. (Pic 7)
Attachment 56330

8) Take a note/photo of the routing and location of the hoses coming from the bottom of the tank in case any become accidentally disconnected, there will be 4 plus an electrical connector. I disconnected the pump wiring to make sure the fuel rail doesnt get pressurised when I am doing my checks later (to minimise the risk of accidentally spilling/leaking fuel). (pic 8)
Attachment 56331

9) Go to the left side of the bike, reroute the overflow hoses that are coming out of the hole above the sprocket cover to get them out of the way, just stuff them by the chock for the time being. Put your hand through this hole and past the starter motor, your other hand can go between the shock and the rear subframe to get at it from the front. (pic 9)
Attachment 56332
10) Looking through the hole by the sprocket cover where your hand just was, this is the speed sensor, it is held on with two 10mm bolts and has 3 wires with a 3 pin plug at the end coming from it. It is very difficult to get your hand in there and you will wish you had girl hands by the end of it. (pic 10)
Attachment 56333

These two steps are optional but are probably worth doing.

11) To check the sensor: Follow the wiring from the top of the sensor to the wiring loom, reconnect the battery, switch on the ignition and check for about 12v between the black and green wires on the 3 pin connector – stuff the multimeter pins into the back of the VSS plug (It is VERY hard to reach, I used needle type multimeter wires, clamps and cable ties to get them into position – very fiddly).

12) Position your multimeter between the pink and green terminals, spin the wheel by hand and check for 5v peaks as the VSS sends a pulse. If no reading is obtained then your VSS is probably knackered. Buy a new one. If it does give a pulse then it may still be knackered but could mean that your clocks are faulty. If like me, you get about 30s of working speedo at the beginning of most rides then this probably doesnt tell you any more than you already know because the speed sensor is likely to be working but only intermittently.

13) If you have a fault the 1st thing to check is the condition of the metal contacts at the plug on the VSS and the loom end of the wiring. I had a bit of green furring and a bit of grease built up in the plug. Spray everything down with the contact cleaner and try and file/sand the contacts a bit to reveal shiny metal. It is extremely difficult to get to the wiring loom end of the plug, I don’t have photos of this as both of my hands were needed to get to it. Needless to say this is an arse of a job. (pic 13)
Attachment 56324

14) Either repeat the above tests to see if the cleaning worked or get on and remove the VSS. Set up your socket extensions, have the 6 inch extension connected to the universal joint and then have a smaller extension with a 10mm socket on the end or just use a deep 10mm socket. This is the routing of the sockets to get at the sensor bolts. (pic 14)
Attachment 56325

15) Position the deep 10mm socket over one of the VSS bolts, you will need to force the coolant hose out of the way to get to it. I found it easier to get the socket in position without the extensions and universal joints first, then slot the extensions in from the top through the hole just in front of the rear subframe. (pic 15a and 15b)

Attachment 56326
Attachment 56327
16) Remove both bolts, then unplug (if you havent already) and remove the sensor, there is a rubber O ring around the base of the sensor, don’t let this drop into the crankcase – it might be left in the VSS hole, replace it when you replace the sensor.


17) This is the speed sensor. It is magnetic and it has been proposed that the reason it fails intermittently is the build up of metallic particles on the outside of the sensor. I didnt actually replace my sensor this time, I was testing out the theory that cleaning these particles off might help it. I did just this, and cleaned out the connector plug with a file and contact cleaner and there has been no change in my speedo situation.
I need to buy a new one, at a stupid Honda stealership price of £120. (pic 17)
Attachment 56328

18) Installation is the reverse of removal, the only thing to add is that it is important to get the speed sensor round the right way round, the bolt holes don’t align if the wiring exits the sensor forwards so turn it round if you cannot get the second bolt to line up.

In short, bolt the new sensor back down, plug it in at the loom. Reconnect everything, lower the tank, replace the rubbers and metal pieces at the top of the tank, bolt it down. Either check it with a multimeter or replace the fairings and go for a test ride. Buy beer if it has worked and cry if it hasn’t.


Also be sure to reroute the overflow hoses and make sure you plug all the connectors back in, you may have unplugged:

Fuel pump wiring
Battery
VSS wiring
The breather on the tank is very easy to dislodge so check it is stuck back on before you lower the tank.

End

Excellent post. I managed to do this procedure on my bike today following your advice.

I'd differ slightly in that I didnt remove the entire left side of the fairing, only the top covers left and right to get the tank propped. I also took out the rear shock absorber to get more room.

The hardest part was getting a socket on over the bolt under the coolant pipe....!

Glad it helped :)

I agree, the coolant pipe is a total PITA and in exactly the wrong position when doing this job.

Hi all,

Sorry to bring this thread back to life but it looks like the speed sensor needs to be replaced on my 04 F4i & I can't view the pics in this thread. I thought I'd kill two birds and post on the forum to let the admins know that I am not a bot nor a rich Nigerian prince and reference the thread that looks like it will make this work a little easier, one I can view the pics that is. Of course, the pics may be gone too.

The symptoms are once the bike gets hot (normal operating temp) after 20 minutes or so of riding, the speed goes to zero and the FI light comes on. I pulled the codes and it says the speed seror is bad. I have a new one sitting right here just waiting to be installed.

cove

I am unable to view the photos. is there anyway to view these?

Weird I can see them but no worries, I will put them on photobucket tonight and upload them.


Yours sounds v similar to mine though so I would highly suspect the speed sensor.



EDIT: Photos uploaded, hope you can see them.

The speed sensor on this bike is crap and in a really bad position, the task itself is very simple just a bit of a pain.


Good luck!

i had the same problem. speedo would not register did some digging and found out it was the kph to mph converter. if you follow the wire from the speedo sensor it is a little black box with 3 wires on each side. un clip it and join the two wires together. take your bike for a spin to see if it works. your clock will be in kph but will do until you can get a replacement converter plus i can guarentee its a hell of a lot cheaper than a 150 quid speedo sensor.

Thanks for the guide
 

Hi, just wanted to thank you for this guide. I did the speed sensor swap today! It took a lot longer than i expected, luckily i had a friend with small hands to help. I would never of managed it myself. All done and working. Well chuffed. I bought the part from partzilla in america. 60 dollars and 40 delivery. Still half price compared to uk prices.