Our CF75 (08) has been running like clockwork since we bought it 18 months ago. However the other week she started flashing an engine fault, dipping in power and conking out so brought out the local DAF agent where it happened. He diagnosed a crankshaft sensor, which they replaced but didn’t solve the problem. Managed to get us home though. The truck has now been seen by a number of mechanics and we’re none the wiser as to what’s going on. At first we thought it may have been a timing issue but its looking more and more electrical as time goes on. The truck has now began to rev intermittently and not react to the throttle and the cruise control refuses to engage. It can go through periods of running faultlessly and then suddenly drop power. We’ve been through wiring looms, vic boards, diagnostics, throttle sensors, Cruise control switches.
Has anyone seen or had an issue similar to this or have any suggestions as to what it may be. Been off the road for four weeks now and its beginning to really pinch.
Do you know what the fault codes where ■■?..It sounds electrical .To be honest start with the basics ,Make sure all basic electrical connections are sound ie battery ,alternator ,mega fuses if fitted ,and feeds and earths at the bulkhead,also make sure the earths are sound removing and cleaning them if required…
The cruise won’t work if there is an issue with the brake pedal /clutch pedal switches
I have known the NOX sensors to cause issues ,though from here it is difficult to say
The fault codes would really be helpful
Hi Norb,
I’ll be talking to the mechanic later and I’ll get those for you. Any other info I should ask about?
Norb,
The DAF agents that put it on a DAF diagnostic only came back with a crankshaft fault. Of the two agents that looked at it one didn’t have time to spend on it and the other didn’t want to spend time on it. It is currently with a private mechanic I use, he’s a good guy and he has been quite thorough. He used a Dephi diagnostic device and the codes currently showing are
P 0335 Crankshaft
P 2135 Pedal Sensor
P 1335 Crankshaft
P 1337 Crankshaft
The engine fault is a nuisance but its not making it undriveable. It would hiccup and drop power momentarily while driving or when idle but now it has started also revving independently, not responding to the throttle and losing all power to the extent you have to crawl to the side off the road. Next day it could run fine for a few hours.
The mechanic has been through the visible wiring (found one tiny broken earth) Crankshaft sensors, Throttle position sensor, Cruise control switch, finally relented and opened the wiring loom reluctantly, had a look at the VIC and bar replacing the two ECU’s has gone through pretty much everything he can think off.
Next stop is an oscilloscope to check the crankshaft but that wouldn’t explain the throttle issue so we’re convinced the issue is electrical all along.
Hi,
I have had this problem on my LF45, LF55s and CF65. I did the same as you and came up with the same faults, I had all the sensors changed, even the immobiliser on the CF and still the same problem. After a bit of internet searching I found there is a fuel metering valve on the high pressure fuel pump and tried changing this. It does not show on the diagnostics ( I have my own Delphi). I changed this each time and sorted the problem CF 6 moths not faults, LF45 18 months no faults and LF 55 no emissions lights or limp mode 3 months and better fuel consumption.
Try this it worked for me
some of the dafs had wiringloom problems which give different problems the loom fills with water … not all daf dealers know of this …was told by electricians who had a load to fix as they couldnt find the fault in the dealers…
scania topline:
some of the dafs had wiringloom problems which give different problems the loom fills with water … not all daf dealers know of this …was told by electricians who had a load to fix as they couldnt find the fault in the dealers…
Not having a go at you as what you say about looms is correct ,but any DAF dealer who never knew about wiring issues would be best to hand back the franchise 
Greenhorn:
Norb,The DAF agents that put it on a DAF diagnostic only came back with a crankshaft fault. Of the two agents that looked at it one didn’t have time to spend on it and the other didn’t want to spend time on it. It is currently with a private mechanic I use, he’s a good guy and he has been quite thorough. He used a Dephi diagnostic device and the codes currently showing are
P 0335 Crankshaft
P 2135 Pedal Sensor
P 1335 Crankshaft
P 1337 Crankshaft
The engine fault is a nuisance but its not making it undriveable. It would hiccup and drop power momentarily while driving or when idle but now it has started also revving independently, not responding to the throttle and losing all power to the extent you have to crawl to the side off the road. Next day it could run fine for a few hours.
The mechanic has been through the visible wiring (found one tiny broken earth) Crankshaft sensors, Throttle position sensor, Cruise control switch, finally relented and opened the wiring loom reluctantly, had a look at the VIC and bar replacing the two ECU’s has gone through pretty much everything he can think off.Next stop is an oscilloscope to check the crankshaft but that wouldn’t explain the throttle issue so we’re convinced the issue is electrical all along.
Hi
I have had a look at the fault codes ,1 question I have ,has there been any engine work been recently carried out ? Reason I ask is the flywheel has holes drilled in it which the crank sensor will read .What can occasionally happen is an operator when it comes to turn the engine over by hand ie valve adjustment will put a bar in to the holes to turn the engine over ,this damages the holes and the sensor then reads incorrectly which will cause all sorts of problems
Anyway to you fault codes
P2135 The throttle pedal …Causes ,interruption on pin B37 of the ECU
interruption on pin B38 of the ECU
Interruption ,short circuit to earth on pin B41 of the ECU
short circuit to supply on pin B41 of the ECU
short circuit between pins B33 & B37 of the ECU
short circuit between pins B38 & B41 of the ECU
fauty pedal sensor
P1337 poor connection
faulty sensor
air gap between sensor and crank ( sometimes corrosion can get between the sensor and the bellhousing …Removing the sensor and polishing the bellhousing with some emery cloth usually sorts it ,sensor may not have been pushed fully home .and external influences
P0335 Interruption or short circuit to supply or earth
interruption in the wiring of pin A49 and or pin A50
faulty sensor
air gap
damaged holes in flywheel
P1335 Short ciruit to supply and or earth on pins A49 A50
faulty sensor
air gap
Obviously certain faults are common to multiple codes
Check where the loom plugs in to the throttle pedal if water has got in the that is your problem…The plug you need should be a purple one located top centre of the cab junction …wires of the top of my head should be 3 twisted wires black blue and grey,and two solo black wires I think are 4166 4680…thats if DAF haven’t changed the numbers etc…Wiring usually fails where it flexs where the cab tilts ,a close inspection of the loom may show where it may have been rubbing against brackets
The crank sensor loom is generally ok ,it just runs from the sensor to the ecu ,and it is pretty bullet proof
If you lad pulls the plugs at the ecu and at the bulkhead…Then put 1 of his multimeter leads to earth (whilst set to ohms) if he then puts the other lead on to each throttle pedal wire he should not get a reading his meter should read open circuit,if he doe get a read ing then that wire if faulty …The same check is used for the crank wiring
When you say it revs independently,do the revs o to a 1000 rpm ■■? If so that is a throttle fault,if the wiring checks ok then you will need a pedal sensor ,easy to change ,held on to the pedal with 2 screws,dont think they are that dear
Going by your fault codes ,the VIC IS INNOCENT .
Wires pass through the bulkhead at plug 3C you wil see the graph on the bulkhead
the 3 twisted wires at in pins 1,2,3 wire numbers are 4677 ,4678,4679, then the 2 black solo wires pins 4 and 5 wires 4166 4680
Let us know how you get on
Thanks lads, I’ll show your posts to the mechanic and he can check out anything he hasn’t checked already.
No work was done on the engine since I bought it Norb. Anything there to suggest it could be an ECU issue? Ever see the timing between the cam and crankshaft to be out of sync because of wear on the timing gears?
J Brickell:
Hi,
I have had this problem on my LF45, LF55s and CF65. I did the same as you and came up with the same faults, I hyou’v the sensors changed, even the immobiliser on the CF and still the same problem. After a bit of internet searching I found there is a fuel metering valve on the high pressure fuel pump and tried changing this. It does not show on the diagnostics ( I have my own Delphi). I changed this each time and sorted the problem CF 6 moths not faults, LF45 18 months no faults and LF 55 no emissions lights or limp mode 3 months and better fuel consumption.
Try this it worked for me
Interesting one, my adblue fault light came on when this issue arrived also but we’re assuming thats because its running rough. Either you have horrible luck getting it on 3 trucks or it must be a common problem. You wouldn’t have a link to where you found that info would you?
norb:
When you say it revs independently,do the revs o to a 1000 rpm ■■? If so that is a throttle fault,if the wiring checks ok then you will need a pedal sensor ,easy to change ,held on to the pedal with 2 screws,dont think they are that dearGoing by your fault codes ,the VIC IS INNOCENT .
Let us know how you get on
I’m nearly certain he’s changed it already but its still intermittent. Comes back yesterday, gone today, all without the truck moving out of his shed.
Greenhorn:
Thanks lads, I’ll show your posts to the mechanic and he can check out anything he hasn’t checked already.No work was done on the engine since I bought it Norb. Anything there to suggest it could be an ECU issue? Ever see the timing between the cam and crankshaft to be out of sync because of wear on the timing gears?
Nothing to say any ecu has issues,timing is ok have never known the gears to wear
Greenhorn:
J Brickell:
Hi,
I have had this problem on my LF45, LF55s and CF65. I did the same as you and came up with the same faults, I hyou’v the sensors changed, even the immobiliser on the CF and still the same problem. After a bit of internet searching I found there is a fuel metering valve on the high pressure fuel pump and tried changing this. It does not show on the diagnostics ( I have my own Delphi). I changed this each time and sorted the problem CF 6 moths not faults, LF45 18 months no faults and LF 55 no emissions lights or limp mode 3 months and better fuel consumption.
Try this it worked for meInteresting one, my adblue fault light came on when this issue arrived also but we’re assuming thats because its running rough. Either you have horrible luck getting it on 3 trucks or it must be a common problem. You wouldn’t have a link to where you found that info would you?
The LF 45 55 & CF65 use the ■■■■■■■ engine ,CF75 runs a DAF px pe engine ,I can never remember its code
The mil light doesn’t mean it has an ad blue fault…
Id get the wiring for the throttle checked…at the bulk head it is easy to access and check down to the ecu and up to the pedal
norb:
The LF 45 55 & CF65 use the ■■■■■■■ engine ,CF75 runs a DAF px pe engine ,I can never remember its code
The mil light doesn’t mean it has an ad blue fault…Id get the wiring for the throttle checked…at the bulk head it is easy to access and check down to the ecu and up to the pedal
Could this register as an engine fault? The throttle issue and revving is only a recent development i.e. in the last week but the initial problem developed about 5 weeks ago.
I first had it on my 45 same faults as you discribed I then found an old post on here about a DAF horse box with similar problems (cutting out for no reason) which was cured by changing the metering Valve on the fuel pump.
My 45 would drive fine then just die for no reason, then also show engine warning light. We just coasted to a stop waited then she fired up and was ok until the next time. I changed the throttle pedal and other bits and it still did it. It also idled rough I thought it might be timing but changing the valve in the pump cured it and I have not yet had another problem.
Last year I brought a CF65 and this would just cut out, lose power as you said above. I had forgotten about the 45 so changed the throttle pedal, changed the sensors even the immobiliser as I thought it could be this but it kept cutting out. I then remembered the 45 changed the same valve no more problems.
I was also having problems with 2 of my LF55’s both putting on the emmisions light and going into limp mode. One was worse than the other. It got so bad I brought my own delphi system as using DAF was costing a fourtune. The diagnostics kept coming up NOX sensor, crank sensor etc etc. I changed all of these still the problem went on. I even changed all the sensors on one lorry still no joy. I said to my mechanic as last resort chuck that fuel pump valve on and see what happens.
No emmisions light no limp. Did it to the other one also cured that also. I have now changed them on my other 2 55’s just in case.
This valve never showed on any diagnostics at all.
Also all are 58 reg except the 45 which is older.
My mechanic who is old school presumes these are a bit like a coil and lose strength over time but the other systems mask them but when they get so bad they don’t control the fuel properly and that then throws everything else out.
It costs about £100 so worth a try. As I said it worked 4 times for me.
It could be engine related in the fact that say the flywheel holes where damaged ,so there is the possibility ,but a sensor is then involved that it is picking up a spurious reading ,though it does sound electrical,i take it the vehicle starts ok in the morning and just has an intermittent fault …Get your lad to clear any faults ,then road test it,hopefully it faults and see what is in the memory.Some times people don’t clear the memory after a repair
norb:
It could be engine related in the fact that say the flywheel holes where damaged ,so there is the possibility ,but a sensor is then involved that it is picking up a spurious reading ,though it does sound electrical,i take it the vehicle starts ok in the morning and just has an intermittent fault …Get your lad to clear any faults ,then road test it,hopefully it faults and see what is in the memory.Some times people don’t clear the memory after a repair
Memory has been cleared a number of times but engine fault appears immediately on start up. Only once did it not register on start up but appeared within 5 mins
if it is they 4 faults ,then everything that I wrote down to check for they fault codes need to be checked …They are the issues which cause those specific faults to become active…If your lad works through them he should hopefully cure the issue ,You may have more than 1 fault
Just a quick post to let you know that it turned out to be an intermittent fault in the ecu. Have it replaced now and she’s back to running like a clock.
Thanks for the suggestions anyway lads