Intermitent speedometer,multiple warning lights on display,DTCO tacho fault codes 19 to 21.No faults logged on E.C.U.Daf agent struggling to find out whats going on.Truck runs perfect.Any body out there had similar problems…any ideas ?
Tacho sender is faulty .Done a few myself.The faults in the other systems will probably be speed signal related
MIxer ?
hmm had that on a Volvo FM when I did TK Max it would show speed limits of 60mph or other limits even when stationary they said thy couldn’t find any fault and didn’t believe me. stopped this one night at the gate and managed to get it recorded on the phone … never knew what the outcome was
Code 19 is faulty sensor wiring or faulty sensor
Code 20 is again faulty wiring or faulty sensor
Code 21 same again
Code 22 same again
It isn’t difficult to check the wiring ,the problem they may be having is that they are using the stoneridge optimo ,which can test a sensor ,I’ve have never found it to throw up a faulty sender ,even when they are faulty…
There is a bad batch of senders and you probably have one…
I’m having a guess that it is also an automatic
Thanks for that chaps…yes it is a mixer…with manual gearbox…back in main agents again next tuesday.Have to politely suggest they
change the sender !
i’ll put money on it being the sender…let us know how you get on
had a 85cf do the exact same, replaced sender and sorted, a month later same again, replace wiring and fixed
Well we do know the wiring issues are legendary 
…I rewire it using rubberised 4 core ,stays flexible and never had it fail yet 
The new looms that have been installed for about a year now with the car style plugs ,seem to be holding up well .And the installation on the Euro 6 motors looks to have hopefully sorted a lot of the issues
With a 13 plate i’ll stick with my sender
Also depends where he took it Norb
Very true neversweat ,though any tacho centre ,and especially a dealer who knows ,where the wires exit the bulkhead , generally where the loom fails , has access to a helpline and bulletins ,and to top it off there will be more than 1 tacho guy 
The optimo is good at checking the wiring ,it is just the sender it is useless at …Though I still like using my multimeter ,put it on ohms an see if any wire is shorting to earth or each other…
All sorted ( I hope).T’was the sensor.Brian Curries tacho man Jim at Milton Keynes Daf sorted it in no time.All warning lights have now gone ( I can’t spell disappeared).Again,thanks for your help.
Cheers for letting us know what the outcome was…