no cotrol of throttle

[rob70]

This is a very nasty fault, dash says ignition fault but the car accelerated away all on its own the only way to slow it down without deglutching is to brake. If you declutch the engine blips upto 2000revs and back down several times . press stop and all is ok for about 2 weeks then it does it again. Should have said the car is a 1.6 Megane II cabriolet with the K4M 760 engine.

[AlexB]

Start with OBD, looking at the fuel trim. It may show a vacuum leak in the intake manifold or antipollution system. It will also flag any problems with the throttle pedal. If not the case, then it could be the throttle body...

[fredcamp2]

The fault your experiencing is not uncommon to Renaults as they suffer a lot with from wiring problems interference from other circuits. could even be a ecu fault. I'm going to give you a few a few basic's to check The 4 signal re-turn wires from the acc pedal sensor to the ecu (input) at key on check voltages at the following ecu pin no's
ecu pin no 1f3 throttle pedal fully closed o.15v-o.3v
ecu pin no 1f3 throttle pedal fully open 1.75-2v's
ecu pin no 1h2 throttle pedal fully closed o.3v's
ecu pin no 1h2 throttle pedal fully open 3.5v's-4v's Can you check & post back Hth Regards fredcamp2

[rob70]

Thanks will check and post results

[rob70]

The readings are as follows Battery voltage at test 12.7v

1F3 throttle closed 0.18
1F3 throttle open 3.1v
1H2 throttle closed 0.17v
1H2throttle open 3.53 ( reading a bit unstable cleaned plugs and skt with switch cleaner but still the same)
Trouble is car is again running ok

[AlexB]

OBD -- your car has a powerful diagnostic system built in! ELM327 is £5-10 on ebay.

[rob70]

Ran car thru Diagnostics at garage,only major code that might produce fault was DF017 flywheel target fault) but mechanic was dubious that this was fault. Reprogrammed throttle so now we wait till next time.

[rob70]

Thought I would update this fault. Since the throttle was reprogrammed there has been no further problems since October(touch wood). I think that when most people have the throttle body cleaned they naturally unplug the lead to the EMU this will in itself cause a reset to the EMU and I think it is this which clears the fault rather than the cleaning of the unit.

[rob70]

Here we go again the throttle fault has surfaced once more. I have ordered a second hand throttle body from ebay and a second hand EMU. I hope this will cure the fault but I probably won't know for some weeks. It is now 18 months since I replaced the Dephaser unit. I am now on my fourth set of pencil coils and the car has only done 100 kilometers,not a lot for a modern car. As I said before the car is MK2 megane cabriolet K4M engine.I am loath to sell the car until I cure this fault as it could cause a nasty accident to an inexperienced driver.

PS I got the dephaser kit from ebay and it contained all the parts cambelt etc needed for the replacement a good bargain at £90 from Poland

[rob70]

Hello once again

The no control of the throttle problem has I hope finally been solved. The diagnostics revealed nothing which pertained to this fault. The EMU and the throttle body did not cure the fault,what did was a new throttle pedal unit . It was just a matter of replacing everything I could think of until the fault went away. Luckily the fault stayed on while replacing the various items which control throttle position.