Hi, I too have exactly the same problem. Its not the components failing my Laguna II 2001 has had the throttle body changed and I am convinced that its either a wiring issue from the throttle body to the ECU as my wires have also been changed or the accel pedal wiring to the ecu. If you take the battery off for an hour the fault will go away and come back. I also took out the ECU cleaned pins and plug sockets (3) and it worked for a while until it reappeared. I have ordered a pedal to eliminate this from the problem. I get code P0120 Throttle potentiometer so my next task will be to check wiring from pedal to ECU. I did strip the pedal down its only a PCB with wipers so there not much to go wrong other than a bad connection or board eroded away. Its the wiring believe me once I plug it all back works fine for a while.
If you find out anything more let me know. I get injection fault and the revs are up and down.

turbineguy

 

thanks for your reply im going to take the acc pedal off my dads car as he has the same type laguna f4r manual. failing that im might need to recheck all throttle body and pedal wires. i'm really running out of ideas.

cheers

 

Can you post up your engine code as you only posted 1 half of it as there are 4 different engine codes for these the 3 numbers after the f4r is required

 

hi there
the pedal off dads car was different, his one has cruise control.
the engine code f4r712.
thanks

 

The acc pedal sensor on your pedal has a 6 in line terminal plug clearly marked 1 to 6 The following data should hopefully help
Bg4 Bg3 Bm3 Bm4 Bg2 Bd3 Ecu pin no's
1 2 3 4 5 6 Acc pedal no's
The 6 terminals are as follows terms 4 & 5 are 2 5v feeds from ecu Terms 1 & 2 are earth return wires to ecu Terms 3 & 6 are signal return wires to ecu This should allow you to check out wiring from acc pedal sen to ecu plug Hth Regards Mickeybo

 

thanks man will check that in the morning, i have a new pedal coming tomorrow as well see how i go and let you know.

cheers rsparis

 

Hi, I got my pedal today. I knew that it would make no difference but I have eliminated this out of the picture. Next step is to check for continuity between the pedal wires and the ECU wire by wire colour by colour. If I am not satisfied that the wires are good then I will replace them.
So to date:
changed throttle body
changed accel pedal
replaced wires for throttle body
cleaned all pins and plugs at ECU (this is where the fault may lie) as the plug pin sockets weaken
I need know to find out what voltages should be at the throttle body and pedal any ideas?

 

A continuity Test (check) will tell you nothing on car wiring if theres 8 strands of wire within the cable your checking and 7 of them broken you will still get continuity but it wont carry a load Do a ohms check on this first plug to plug.This wiring may need to be load tested. Hth Regards Mickeybo

 

hi turbineguy,
attached is some info hope it helps you. im still waiting for my pedal to arrive.
there are 60 pages let me know if you can't read it
Cheers Noel

 

mickeybo
thats a good point i'm going recheck all wiring this afternoon just to make sure

Cheers

 

Hi guys an update on my Laguna problem checked and recheck all wireing and connectors they were found good replaced throttle body acc pedal but no fix. Checked power and earth to throttle body and found good earth but lost engine positive from pin number 4 on throttle body plug check to see if it had power at the ecu plug and no power there either. My conclusion is that the engine ecu has crapped it. Does anyone know if the ecu can be taken from another car to try. The reason I ask is the Laguna one can be done as long as you don't touch the central locking. Thanks for the people who replied to first post.

 

The throttle body 6 terminals are as follows
bg4 bg3 bm3 bm4 bg2 bd3 Ecu pin no's
1 2 3 4 5 6 Numbers on throttle body plug
Terminal 1 Earth (bg4) Terminal 2 key on o.5 approx (bg3) Throttle closed Throttle fully open key on again at (bg3) approx voltage 4.3 Terminals 3 & 4 are the the throttle motor terminals A 12v feed to terminal 4 via ecu terminal 3 is the earth the throttle motor should have approx 8 ohms measured between terminals 3 & 4 At key on terminal 5 should have a 5v feed Hth Regards Mickeybo

 

Hi do you have the circuit diagram for this? What I have done is to cut the wires at the ECU plug (centre plug) and at the throttle body to see if there was any intereference in the wiring. Before I did this the car was going 2000-3000 revs but would settle down when warm but still have the injection light on but once I cut the wires and connected them with fresh wire the fault stays there all the time. Today I am going to solder the connections back as they were and test the voltages but I am unsure of the voltages as you state can you explain them in lamens terms for an idiot to understand please?
thanks turbineguy

 

Hi guys
i received my engine ecu today and was told by my local renault dealer that it should be a plug and play unit, also to print the old configuration off the old ecu to match up with the new one. the new ecu is not detected on our renault clip v119. is there something i have missed. any help would be great as i need the get this car going asap.

cheers rsparis

 

Hi, do you have a circuit diagram for the laguna 2 2001 petrol F4 engine?
thanks

 

injection light means there is a ECU emmisions or feedback error.
have you tried changing the Temp sensor.
(i had this one on mine, excessive fuel consumption and the error, changed the sensor and it went away after a run(150 consecutive readings and either the error clears or activates the engine error.))

getting some secondhand spare sensors from a scrapper is the best bet to cover some faults. MAP air pressure sensor, air temp sensor, dephaser solinoid, tdc, pencil coil and a lamda sensor(top and bottom are both the same part.)

and yes i do have the AutoData wiring diagram for the F4P-770/1, as well as Diagolys pdf manuals.

the engine ECU is pretty stupid, not all that many sensors.
if it looses feedback it drops into one of several limp modes. throttle/body, emissions feedback, crank tdc detection, engine RPM is one indicator of what the problem is.

look online for 2.0 clio engine manuals (they have the same engine, though the heads can vary.)they will have the fault diagnosing instructions.

 

Hi, can you email me and the members the manual as I do not have one would that be possible or at least pdf the page that shows me the ecu pedal and throttle body? Your help is appreciated.thanks

 

Hi again, UPDATE.
Checking the throttle body I have all the correct signals EXCEPT any voltage on the motor positive on pin 4 therefore, I checked the output from the ECU still no voltage so where does the motor get its positive feed from ? it must come from the battery through the ECU so which pin is it on which plug going in? Once I know this I will know if the ECU is faulty. Thanks

 

I have already posted up the correct data for the Throttle valve control unit. But to put you in the picture better.The throttle control motor on this control unit gets its 12v directly from ecu pin no bm4 to control unit terminal 4which then travels through motor coil to terminal 3 and then on to ecu earth at pin no bm3 to activate the motor The colour for both wires bm3 & bm4 Are cream Hth Regards Mickeybo

 

I appreciate your help but I dont understand where bm4 is ? Does B represent the centre socket on the ECU and M4 the pin no (which incidentely is one of the six larger pins) as marked inside on the black plastic? Yes the wires are cream one has a black trace mark on it. What does Hth mean?
I do have the earth at pin 1 on the socket at the throttle body and the 5 volt at pin 5 I am just missing the voltage positive at pin 4 so my last question is there must be an input to the ECU via another pin then goes out to pin bm4? What controls the motor is it a variable voltage from the accelerator pedal? If there is no input there would be no output correct? but if there is an input and no output then the ECU is faulty thats my reasoning.
Sorry to be a pain but as I say I am new to this stuff.
regards turbineguy

 

Hi,
I have quite the same probems...I am owner of VS 2.0t with LPG installation, 2002 year with F4R, same as laguna II.
Two months ago, while driving, the car prompted Fuel Injection fault(body throttle regulation is switch off and motor is at cca 3500 RPM).
At the R service, the body throttle was replaced (new), as they said that the potentiometers of both measuring tracks were dead. After replacement the problem occurred again and again… INJ fault, ESP & ABS fault, handbrake… this is all connected with ECU fault behavior, as I was told.
They checked all the wiring of ECU, body throttle, gas pedal, …. all the connections to the injection ECU, replaced all ECU relays, connection between ECU and body throttle…
Finally they concluded that ECU is faulty and I bought used one. But the problem stayed…so ECU seems it is OK…unless both ECU had the same fault
ECU was also upgraded with last FW (some posts suggests upgrade for laguna).
They have no clue how to help me,…. I forgot to mention, that car was moved also to second R dealer/service…but also no luck…
Now they are waiting me to allow ordering new ECU which is 1350€… but I am worried that it is not ECU faulty, as the problem is the same from beginning

It is interesting, that after throttle replacement problem/fault occurs when the car is started (during initialization), and not during the drive (during the drive happened just at the beginning, two months ago), or maybe this only by chance.
What else to do...

 

Your quite correct B is the centre plug at m4 pin no ecu must have a 12v output from ecu m4 to throttle motor. I don't know how you checked this wether it was at the throttle body terminal 4 or directly at the ecu plug this could be a ecu problem If i were checking thisi would startby checking wiring from throttle body plug terminal 4 to ecu plug both disconnected at ecu terminal bm4 Hth Regards Mickey (Hth hope this helps)

 

let an auto electrician loose on the wiring loom, its probably a fracturing of the strands of one of the wires, the looms do tend to suffer conectivity faults on occasion, only a continuity test on either end and then flexing the loom will see where the fault is.

the dealership bods, will only follow the manuals logic diagram (at your expense) till either the fault or you go away...

the ECU would ideally need to be scoped in real time to read all signals to see where the problem is.

 

Thanks to you both I just have a few comments.
I am not worried about the OUTPUT from the ECU to the Throttle body motor as I have checked the voltage two inches from the plug of the ECU as I have cut the wires (all six from the throttle body to the ECU) and replaced them. What I need to know now is where does the INPUT for the voltage go in the ECU what pin does it get the feed from? I know the output pin (as there is no voltage) the INPUT feed to the ECU is what I need. The question is, for the motor to be controlled to open the accelerator pedal must send a signal to a pin input to the ECU then the ECU sends this signal out to the throttle body so my issue here is I do not know which input pin the voltage goes in at. If I now this and knowing there is voltage going in and nothing coming out its the ECU at fault. Does anyone understand what I am saying? Thanks.

Turbineguy

 

Hi, when you purchased a used one did it have to be programmed to your key card or did you take the keycard as well and do you still have it? I could borrow it and check mine if you do.
regards
turbineguy

By the way I am an Electrical Engineer but on power electrics not electronics

 

Hi,

No the used ECU was recoded with my codes. Also I am from slovenia, far from UK