Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat unit

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andy1976
Posts: 2
Joined: Tue May 22, 2012 6:27 pm

Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat unit

Postby andy1976 » Tue May 22, 2012 6:47 pm

Can any of you guys help me please. I have the service and check injection light on and have changed all 4 glow plugs, fuel filter changed and have a dianostic code of Df025 on the canclip. Is this fault code just a posh word for the glow plug reley and if so does anyone no were it is located to change and were can i buy a new one from.
Sorry forgot to say the car only puts the dash light on till it warms up after a couple of minutes, That'S why i changed the glow plugs first.
Any help on this would be great.
Thanks
Andrew

davelowe
Driving Legend
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Joined: Thu May 10, 2007 3:40 pm

Re: Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat un

Postby davelowe » Tue May 22, 2012 10:09 pm

There is a regulator behind the bumper (you have to remove it). Check both the wiring and the regulator since you have 'eliminated' the plug faults.

Don't throw parts at it, get some evidence - though this is the likely culprit.

The 1.9 will start with no problem without the plugs. Be wary of closed and open loop operation. The delay worries me, but not least because the ECU supplies power to the relay on demand - not on and off from cold.
Silver 08 plate 5dr 1.5dci Dynamique 106 Tech Run (re-mapped)

Red 03 plate 5dr 1.9 Dynamique dci120

Best advice for Megane owners: sell it before it bankrupts you!

andy1976
Posts: 2
Joined: Tue May 22, 2012 6:27 pm

Re: Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat un

Postby andy1976 » Wed May 23, 2012 12:10 am

what does this regulator look like mate, do you have a pic and what does it do.

davelowe
Driving Legend
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Joined: Thu May 10, 2007 3:40 pm

Re: Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat un

Postby davelowe » Wed May 23, 2012 10:29 pm

It is bolted to the bulkhead (when you disconnect the front fog lamps (yellow connector) - you will see it). It may be covered with a rubber boot, but is a finned aluminium/alloy block about the size of a smallish box of matches. It sticks out like a sore thumb. Note: passenger side. Unfortunately is is in the prime zone for salt & water corrosion. Check its connections are not corroded.

Its function is to supply a variable voltage to the plugs based on many factors from the ECU such as battery voltage, coolant and ambient temperatures. I.E. it is not a relay; not on and off, so to speak.

Hope this helps.
Silver 08 plate 5dr 1.5dci Dynamique 106 Tech Run (re-mapped)

Red 03 plate 5dr 1.9 Dynamique dci120

Best advice for Megane owners: sell it before it bankrupts you!

igorz
Posts: 3
Joined: Tue May 29, 2018 8:34 am

Re: Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat unit

Postby igorz » Tue May 29, 2018 8:38 am

andy1976 wrote:Can any of you guys help me please. I have the service and check injection light on and have changed all 4 glow plugs, fuel filter changed and have a dianostic code of Df025 on the canclip. Is this fault code just a posh word for the glow plug reley and if so does anyone no were it is located to change and were can i buy a new one from.
Sorry forgot to say the car only puts the dash light on till it warms up after a couple of minutes, That'S why i changed the glow plugs first.
Any help on this would be great.
Thanks
Andrew

How you solved the problem I have the same problem, please!!!

grandadbobby
Advanced Driver
Posts: 499
Joined: Thu Feb 16, 2017 9:05 pm
Currently Drives:: megan dynamique estate 1.9dci

Re: Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat unit

Postby grandadbobby » Tue May 29, 2018 10:26 pm

Hi,
does the fault warning go out like in this original post?
Have you checked the glow plugs are working (see how to on you tube).
Have you got the same fault code as above and does the engine start when cold?
You might be better off starting a new post as this is an old one with no resolution it seems.
Bob.

igorz
Posts: 3
Joined: Tue May 29, 2018 8:34 am

Re: Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat unit

Postby igorz » Mon Jun 04, 2018 5:14 am

Car starts like New, after warm up it lost power on secunde and sometime say " injection fault" sam mechanic say it can bre ECU after warm up.

grandadbobby
Advanced Driver
Posts: 499
Joined: Thu Feb 16, 2017 9:05 pm
Currently Drives:: megan dynamique estate 1.9dci

Re: Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat unit

Postby grandadbobby » Mon Jun 04, 2018 8:21 pm

Doesn't sound like a glow plug problem.
You need to read the fault codes, but when you do, read codes, erase them, start engine for a few minutes or drive round the block to warm up, then read again to see what's registering now.
Codes can be old stored ones.
Bob.

igorz
Posts: 3
Joined: Tue May 29, 2018 8:34 am

Re: Renault megane 1.9 DCI 2005 Fault code DF025 pre-heat unit

Postby igorz » Thu Jun 07, 2018 6:55 pm

The mechanic check error code, one whole day. Sesveral times diagnostic lost conection with ECU when car almost stop on secunde, and say some error thay have no sense, Like some error on 2700 rpm of someting but car was ol time on standby 850rpm. Mechanic say that ECU lost power 12V on secunde and restart, but that happens only wan is warm car, he say 50% but is not sure . After nights car go perfect onli sam 15min and start agine. Ol graund wire a OK, If som wire not ok, way problem start after car is warm or electronic warm up.


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