Rev Counter Speedo Fault

[colinw]

Twice now I have glanced down at the clocks on my 39k mileage 05 gs to see them cycle down to zero then back up to normal ????????????

Has anyone got an idea of cause or witnesed this themselves??

 

[Wapping]

If I had to guess, it's a failing rear drive or ABS sensor.

 

[colinw]

If I had to guess, it's a failing rear drive or ABS sensor.

I thought the speedo collected pulses from the rear abs sensor, but why would a failing rear drive unit or abs sensor cause all dials to drop to zero, that is speedo and rev counter surely the revs are picked up from engine side ??

 

[Wapping]

I thought the speedo collected pulses from the rear abs sensor, but why would a failing rear drive unit or abs sensor cause all dials to drop to zero, that is speedo and rev counter surely the revs are picked up from engine side ??

Good question.

I missed the bit about the rev counter dropping as well as the speedo.

 

[davedyer]

I would guess it's a part of the circuit that they share that is failing intermittently. A common ground? Return wire on the can-bus? Have you checked the connector at the back of the instruments?

 

[SVENA]

Twice now I have glanced down at the clocks on my 39k mileage 05 gs to see them cycle down to zero then back up to normal ????????????

Has anyone got an idea of cause or witnesed this themselves??

Check the connector on the backside of the instrument, could be lose

 

[nedflanders]

not sure about the rev counter but when my battery was just about to give up the ghost the speedo stopped working and the ABS light came on. Switched off then on and all ok, happened a few times then the battery died, changed the battery and all's been well since.

 

[KevG]

Hi Colin, Do you loose the gear position indicator and fuel and temp too?

 

[colinw]

Hi Colin, Do you loose the gear position indicator and fuel and temp too?

No I dont think so, but the neutral indicator has been playing up lately, but i think i have cured that by cleaning the plug at the rear of the gearbox. it just seems to be the two needles drop to zero then straight back up, the lights stay on the clocks too!

 

[roadkill]

I had similar but just speedo. Ridin Maroc, when slowing or stopping at lights etc, speedo took ages to show me that I'd stopped. Lasted two weeks, intermittently but cured itself. Also slow to tell me I'd started again!

 

[barneydinosaur]

I had similar but just speedo. Ridin Maroc, when slowing or stopping at lights etc, speedo took ages to show me that I'd stopped. Lasted two weeks, intermittently but cured itself. Also slow to tell me I'd started again!

I have exactly the same problem. It's intermittent and thus very difficult to track down. Fortunately the rev counter appears to be reliable. I'm looking at ways of marking the rev counter to indicate given speeds in certain gears. Otherwise I have a table of gear/revs/speed in my tankbag window for those times when it' not working. (I can remember some but not all of the combinations)

 

[Pukmeister]

It could simply be machining and wear swarf building up on the inductive sensor in the rear bevel drive, due to its magnetism. This feeds in to the ABS and Speedo circuits. Worth taking out and cleaning (don't lose the o ring).

 

[barneydinosaur]

It could simply be machining and wear swarf building up on the inductive sensor in the rear bevel drive, due to its magnetism. This feeds in to the ABS and Speedo circuits. Worth taking out and cleaning (don't lose the o ring).

Thanks, I'll have a go. Are there any particular issues associated with taking it out? I tried a while back but it seemed pretty stiff so I didn't force it.

 

[Pukmeister]

Thanks, I'll have a go. Are there any particular issues associated with taking it out? I tried a while back but it seemed pretty stiff so I didn't force it.

IIRC I just cleaned around the sensor with an old toothbrush to remove dirt, then undid the tiny TORX retaining screw and prised out the sensor from the rear drive unit, being careful not to lose the sealing ring.