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Discussion Starter #1 (Edited)
What sensor read out speed? - 156 [Temporary solved]

Hi, have a strange problem which will probbly cost me a LOT to repair :D

Everytime I clutch/shift my speed-o drops and gets back up again once i shifted. I have a bad feeling thats its something inside the gearbox thats wrong and not the sensor..This can happend aswell that the speed-o moves uneven once I enginebrakes.

156 2.5 -99
 

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Speedometer is driven by pulses from the ABS system, so it shouldn't be related to / caused by any gearbox issues. May be worth checking your wiring to the ABS sensors / ABS pump/ECU ?
 

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Discussion Starter #3
Checked cable that goes from ABS to Speedo, 0 Ohm resistance and put some presure on it with a blub. Lighted up without any problem..May the speedo itself be bad?

Still saving for diagnostic cables.. :D
 
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Didnt manage to get ABS codes but had engine code:

P0500 Vehicle speed signal
Check the wire that runs from the speed sensor located on the passenger side wheel hub all the way to the inner wing. It's usually secured to the front strut but can work loose on occasion. Any wear or rubbing from the tyre can cause this fault code.

But.... Another possibility....Are you getting an intermittent signal to the rev counter? Is it showing the correct revs then all of a sudden dropping the revs then back to normal without no apparent tone in revs dropping in unison?
If so... It could be the rev counter itself.

Bring back Tapatalk !!!
 

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Discussion Starter #6
Passenger side as left?

If so it hangs like nothing else and been slapping the driveshaft :)

The rev counter works perfect, but the speedo can randomly drop if its hot in car (If it stand in sun for some hours) plus it getting jumpy.
 
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Passenger side as left?

If so it hangs like nothing else and been slapping the driveshaft :)

The rev counter works perfect, but the speedo can randomly drop if its hot in car (If it stand in sun for some hours) plus it getting jumpy.
Yes, left hand side... That's the one. If the wire has been damaged or pulled in any way then that would explain the symptoms and fault code you are experiencing. Using a multimeter, strip back the insulation near the hub sensor and further up the inner wing to check for continuity on both wires. If there isn't any, strip it further down and check again until you know where the wire is damaged. Cut out the damaged wire and re-solder a good section in then tape it up and secure it to the correct position on the front strut bracket. Cheapest fix.

Or... Replace the speed sensor in the hub which comes a new wire complete and plug but a bit expensive.

I would do the first option/fix before spending any money on new parts just to make sure it does actually eliminate the issue first;)

Bring back Tapatalk !!!
 

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Discussion Starter #8
Re-rounted the cable to its right place when changing the clutch, the problem remains but so far seems to jump -a little- bit less.

Not sure if speedo or cable..
 

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Discussion Starter #9
Once again..something happened.

I had the car standing still for days since I repaired the floor on it, now when I took it out for a drive speedo jumped a LOT, dropping to 0 and raising to 140 kmh when traveling in 90..Got a bit better after driving it for a while but eh.

Makes no sense.
 

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Will do~! If bad, will a 500Ah do?

Could maybe get some cheap Silver Calcium battery from work then.
Sounds like an earthing issue. My 156 had a similar problem, but every thing on the dash was jumping around, turned out to be the main earth cable from the battery to the body
 

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Discussion Starter #13
So if I earth with an start-help cable then things may disapear? Had one loose earth before on cylinderhead which made my Enigne MIL start to slightly light up past 6000 RPM.
 

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Discussion Starter #15
Hello people & others.

I have unplugged the switch that's located at the clutch pedal, the problem have disappeared and the speedo-meter is working correctly.

No engine MIL so far (been driving for a week)
 

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Interesting - a new one on me. Clutch switch is used in connection with cruise control, so that could be the link, I suppose.....

Thanks for information - always good to learn of a fix.
 

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I don't have cruise control, so no damage made? :D

Probably a connection since the CC turns off if you brake or uses clutch.
Cruise control didn't come along until the 2002 interior facelift, so as a 1999 car it won't have been connected with that.
 
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