Daf LF55.180 Euro 3 running issues HELP

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1

Hi there excuse me if this is in the wrong section I’m not very good with computer’s .

I have a Daf lf55.180 recovery vehicle . About 2 months a go i got back from a long journey and parked the lorry up. The following morning i had a call out so got in sharp after literally using the truck the previous day it suddenly started hunting . I went to drive out of my compound and nothing! Totally shut down. No accelerator pedal , Stop warning on the dash and engine management fault on the cluster. I am a vehicle technician to trade so i thought its an old truck ill have a look and see if i can any broken wiring etc , It was all i could do as didn’t have access to HGV diagnostics. I spent all morning just visually inspecting the main loom / fuses relays. I did however find two broken wires deep within the wiring loom that i repaired but made zero difference.

I got hold of a computer and plug for the daf and pulled out these codes:

Now i think some of these where Due to hunting

190-2 Engine speed. Data erratic or intermittent

639-9. J1939 can-bus. No communication. Intermittent

441-15 Smart cooling derate above upper regulation limit threshold. Intermittent

723-2 crankshaft to camshaft signal data erratic . Intermittent

1077-14 HPCR PUMP leakage . Intermittent

157- 4 fuel pressure voltage to low or short circuit to lower voltage . Permanent

I cleared all the codes and the only ones i got back was

157- 4 fuel pressure voltage to low or short circuit to lower voltage . Permanent

And a throttle pedal fault .

So i ordered a fuel pressure sensor at an eye watering price. It didn’t make a difference. Checked the wiring from the ECU to the pressure sensor and was all ok my voltages where also there.

Ive checked the fuel tank isn’t blocked as i read in a previous post on here its common and all good its a relatively new tank. Replaced the fuel filter.

Does anyone on here have the slightest idea what it could be ?

Im edging towards an ECU but again its throwing money i don’t have at parts that mite not fix it. So before i do i thought id come on here and ask . Any advise is appreciated.

It also allows you to rev it hard once from idle then shuts down into sort of limp mode. If i try move the vehicle it shuts the throttle pedal down entirely

2

any idea what the fuel rail pressure should be, and what it actually is ?

Furthermore, in this link, press ctrl f to search , then type 157 - 4 and it’ll show the fault find sequence.

3

Had a few of these on cummins engines and it turned out to be a failed low pressure pump. The low pressure pump is all part of the pump assembly under the fuel filters.Think it was about 600 quid for the pump.Easy fit as no pump timing needed.

4

Thanks for that much appreciated , I still need to check the fuel pressure to be honest been off the road since. Ive replaced the fuel pump with no difference . I need to move yard and the truck is still off the road ive replaced the pump fuel lines and fitted a new tank :man_facepalming:

5

first thing: I’m not a technician.
When I looked back at your list of codes, made me think,
maybe it’s not the ECU itself, but the plug and socket. You’d had a long run before, so probably got nice and hot, then cools down overnight. That plastic at that age tends to go a bit funny, before you know it, you’ve got intermittent contact, which when you’re testing for continuity, you miss because you naturally put the meter tips against the connectors.
I might be sending you in the wrong direction so take it with as much scepticism as you wish.
hope you sort it one way or tuther.

Unless there is some sort of problem with the safety circuit inside the throttle pedal, and the ECU is sensing that fault there, thereby inhibiting proper start up. I assume it has more than just a single position sensor to prevent a fault causing catastrophic engine revs.
It was Toyota cars wasn’t it that had a big problem with that? Toyota argued for years it was only a mechanical problem with mats etc getting stuck under the pedal, and careless drivers…
But again, I’m not a technician. buyer beware :wink: