I drive a scania topline 4 series and mine did the same kept loosing power and scania said it was the throttle pedal so they wanted £600+ for it got 1 from a scrap yard for £150 that’s all fine now but now I have a problem I lost the feed to my nsf indicator my trip meter stopped workin on the dash and speed limiter tacho works fine but this week I have now lost the feed to nsf side light just problems with that corner can anyone help me out ■■? Thanks rob
I would definitely proceed with caution with the dealer as they’re not inspiring confidence.
The problem with fault codes is they just tell you what sensors aren’t receiving the information they’re expecting not what’s actually wrong.
Bit like with brakes when you think a valve is stuck or knackered and then it turns out a hole in a diaphragm or something is letting air go the wrong way.
Batteries do sound like worth investigating although generally will run straight off just the alternator once started unless the belt’s slipping if you’ve ever turned the ignition on a truck with a low battery you’ll see it often causes the electronics to go haywire. On one we’ve got it switches the windscreen wipers and hazards on of its own accord when the battery’s low.
try changing the fuel filter. the slightest bit of crap in a scania fuel filter, and they run like a bag of nails, several fault codes can come up all because of a filter.
Dont want to frighten you but thought i will tell you my experience!
bought a new to me 06 r420 in feb had same light come on after a month,took it bk to scania said it was a prob with the red can bus spiking the system,it had an engine ecu,a suspension ecu,a new co ordinator adding up to over 3k still same prob so went bk and spent 2weeks having all the wiring looms stripped and checked before they thought it could only be a prob with the dash!! they seemed like they didnt have a clue,in the end they had to buy the motor bk off me and supply a hire one while this all went on!! let them get on with it cos wasnt costing me thank god but frightening how these fitters just slap new stuff on with out alot of worry!!!
YapYap:
Dont want to frighten you but thought i will tell you my experience!
bought a new to me 06 r420 in feb had same light come on after a month,took it bk to scania said it was a prob with the red can bus spiking the system,it had an engine ecu,a suspension ecu,a new co ordinator adding up to over 3k still same prob so went bk and spent 2weeks having all the wiring looms stripped and checked before they thought it could only be a prob with the dash!! they seemed like they didnt have a clue,in the end they had to buy the motor bk off me and supply a hire one while this all went on!! let them get on with it cos wasnt costing me thank god but frightening how these fitters just slap new stuff on with out alot of worry!!!
just had a similar experience with a car. it’s this, it’s that, etc, etc. they tried to sell parts that “only come as a complete unit”. 
they didn’t have a clue. they are all just fitters nowadays and rely solely on the computers.
then i was laid in bed one night, had a eureka moment, kicked my lad out of bed, told him to hold the inspection lamp, and 20 minutes later the car was fixed. edc sensor had a bit of soot on it, and whilst i was at it i give the throttle position sensor a good scrub with an old tooth brush, and some wd40.
rob2012:
I drive a scania topline 4 series and mine did the same kept loosing power and scania said it was the throttle pedal so they wanted £600+ for it got 1 from a scrap yard for £150 that’s all fine now but now I have a problem I lost the feed to my nsf indicator my trip meter stopped workin on the dash and speed limiter tacho works fine but this week I have now lost the feed to nsf side light just problems with that corner can anyone help me out ■■? Thanks rob
Rob the looms on the indicators/side lights are prone for break up etc plus the red plug on the loom can cause probs aswell, the wires also break where it bends out of the headlights!! check to see if you have power at the plug first
your trip meter is it working by that i mean look really close at it as they have a bulb in them what blow!! same bulb as a tacho head bulb if the bulb has gone yep it looks liek the trip meter has stopped working,
also the check your loom by the steering box and at back of the o/side headlight as these also break up,
anybody got any ideas edc light came on in 4 series scania throttle cuts off after about 5 miles stop turn off engine then restart goes for onother couple of miles before it does it again advice please oh and onlt sensible ones lol.cheers martyn.
Did the same thing on me a few weeks ago the engine went onto safe mode I switched it off then it went ok again, am told the computer does a check and if it is all ok the engine will start again ok.
But last week it did the same and wouldnt start again after a lot of checks and new fuel filter it turned out to be the vaulve that controls the fuel pressure in the common rail system it was stuck open with a bit of dirt and let the pressure out of the system.
To find it look below the fuel filter and you will see a 18mil nut sitting out of the side of the engine this is the pressure censor I think its called ? if you take it out give it a clean and press it in and out to make sure the spring is working ok inside it and put it back in it should be fine or you can replace it I think it is £320 + vat oh and there is 2 of them the other one is on the same side of the engine about 3/4 way across to the left as you are looking at it but it gives no bother so I am told, give it a try only takes 10mins to pull it out and put it back in again
Hope this all makes some sort of sense to you
Cheers
Robert
Robert:
Did the same thing on me a few weeks ago the engine went onto safe mode I switched it off then it went ok again, am told the computer does a check and if it is all ok the engine will start again ok.But last week it did the same and wouldnt start again after a lot of checks and new fuel filter it turned out to be the vaulve that controls the fuel pressure in the common rail system it was stuck open with a bit of dirt and let the pressure out of the system.
To find it look below the fuel filter and you will see a 18mil nut sitting out of the side of the engine this is the pressure censor I think its called ? if you take it out give it a clean and press it in and out to make sure the spring is working ok inside it and put it back in it should be fine or you can replace it I think it is £320 + vat oh and there is 2 of them the other one is on the same side of the engine about 3/4 way across to the left as you are looking at it but it gives no bother so I am told, give it a try only takes 10mins to pull it out and put it back in againHope this all makes some sort of sense to you
Cheers
Robert
thanks robert ill give that a try cheers martyn.
A throttle potentiometer fault could be to blame, think of the throttle pedal as a scalextrick hand controll, imagine a break in the windings causing a dead spot at 3/4 throttle, not a big problem on your racing car game as you simply give it a little more or a little less and they’re flying. When this happens on your truck it logs a fault on the trucks computer and it goes into ‘limp mode’ normally, switch off and on & the computer does it’s static checks, spots no fault and it lets you start & run. Until it spots the fault and shuts down again.
The best thing is find a garage with a suitable ‘scanner’ to read the fault codes stored in the trucks system, then you’ll know for certain what is causing it to shut down, but it could be hundreds of things!!
Ross.
bigr250:
A throttle potentiometer fault could be to blame, think of the throttle pedal as a scalextrick hand controll, imagine a break in the windings causing a dead spot at 3/4 throttle, not a big problem on your racing car game as you simply give it a little more or a little less and they’re flying. When this happens on your truck it logs a fault on the trucks computer and it goes into ‘limp mode’ normally, switch off and on & the computer does it’s static checks, spots no fault and it lets you start & run. Until it spots the fault and shuts down again.The best thing is find a garage with a suitable ‘scanner’ to read the fault codes stored in the trucks system, then you’ll know for certain what is causing it to shut down, but it could be hundreds of things!!
Ross.
i think ive sorted it know tomorrow if not its got to go to scania,cheers martyn.
please let us know what was the problem might be of some help to others
Robert:
please let us know what was the problem might be of some help to others
right i did nt sort problem so booked into scania how much to plug in me says scania man says £38.00 plus vat half hour labour me says great plug away about half hour man says found problem alternator overcharging how much for a new one i says he says £351.00 plus vat gulp have you got one yes ok better fit new one being as im here ok comes back few minutes later tensioner knackered i say how much he says £200.00 plus vat ■■■■ have you got one he says yes okay then fit it after a while he comes out truck ready oh well i thought at least its fixed now jump into truck to leave light comes back on have to get man back out with laptop checks battery charging ok checks ecu pigging overcharging so its off with the new alternator and on with the old he then says got good news and bad found problem new ecu could be anywhere between £1000.and £1500.00 pounds and guess what they aint got one in uk or sweden or whever bloody scania comes from truck could be off road 1 week or 3mths depending if they have to have one made .made my weekend. 
are they one hundred percent sure its ecu. i know some trucks have voltage sensing wire to alterntor from starter mtr if this wire is corroded off alternator thinks its not giving out enough voltage output and sends out more voltage then when ecu gets 30v it brings up and error and shuts down to protect its self
mattaid:
are they one hundred percent sure its ecu. i know some trucks have voltage sensing wire to alterntor from starter mtr if this wire is corroded off alternator thinks its not giving out enough voltage output and sends out more voltage then when ecu gets 30v it brings up and error and shuts down to protect its self
thats what its saying ecu chucking out 30amps test batterys putting out correct amps 28.something ill try and have a look at the wiring tomorrow cause i dont really think my scania dealer knows really what they are doing and just looking for easy option hoping it will sort problem out thank you very much for that information cheers martyn.
sammy dog:
mattaid:
are they one hundred percent sure its ecu. i know some trucks have voltage sensing wire to alterntor from starter mtr if this wire is corroded off alternator thinks its not giving out enough voltage output and sends out more voltage then when ecu gets 30v it brings up and error and shuts down to protect its selfthats what its saying ecu chucking out 30amps test batterys putting out correct amps 28.something ill try and have a look at the wiring tomorrow cause i dont really think my scania dealer knows really what they are doing and just looking for easy option hoping it will sort problem out thank you very much for that information cheers martyn.
another thing are the batteries ok check for dry cells