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post #1 of (permalink) Old 25th March 2009 Thread Starter
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Angry Scenic Gearbox and Immobilser

Now that I’ve found the forum & been welcomed here’s my initial reason for joining……………..

2 technical faults that cause me concern. I’m sorry if they are described in a long winded manner!

The vehicle is a Y reg 2.0 auto box Megane Scenic Privilege. Since acquiring the car I have found a local mechanic (not a Renault specialist) who has fully serviced it at the 72k stage & fitted a new cam belt & associated pulleys. Thankfully the same mechanic also found & fixed an electrical fault that caused poor running. A coil supply wire had chafed through the insulation & was shorting.

1st problem: auto gear box dash warning light occasionally illuminates. This lasts for a short period (usually no more than a half mile travelled) during which auto changing fails to happen. The box appears to be stuck in a mid range default gear & this more often than not generally occurs shortly after starting the vehicle from cold or standing for a while. The fault light then disappears with normal function restored to the box. The mechanic has code read the ECU which diagnosed a pressure switch matter. BUT reading from another source this also pointed to a need to change & level check the auto fluid levels. This latter action has now been carried out & the level re checked after running for a short while. The frequency of occurrence is less than it was, but it still sometimes happens, maybe now once or twice a month.

My simple, I’m not a mechanic, logical deduction thinks that it’s a very temporary low fluid pressure that arises & then shortly disappears. The mechanic has admitted he’s not an auto specialist & has no idea’s beyond the coded information he read. He’s even suggested going to an auto specialist to investigate further. This I’ve done on 3 occasions & guess what, damn thing won’t malfunction when you want’s it to!

ANY ideas gratefully received…………….

2nd problem: This is current & has arisen intermittently during the past 2 months, progressively getting more frequent of late & therefore becoming un reliable & frustrating.

Vehicle drives faultlessly (if you ignore gearbox matter above), engine runs smoothly and sweetly. However, intermittently, when the vehicle is parked, locked and left, on return it fails to start. The doors centrally unlock normally, by inserting ignition key and turning on the immobiliser dash light stops flashing, illuminates for a short period then goes out, as it should. The starter engages and turns the engine over easily but fails to fire & start. I’ve checked that the vehicle is in P, but then again the starter wouldn’t engage if this weren’t so.

When this initially happened, I found that by removing the ignition key (BTW have checked batteries are ok in these), re locking the vehicle, unlocking again & proceeding normally & maybe doing this two or three times than the car would eventually start and run normally. My thoughts therefore have been that the immobiliser itself is still activated, even though the dash light suggests this is not so & the vehicle alarm is not activated. I also guess that as the immobiliser warning light is activated and de activated that the key’s are being recognised. Is this electronically possible?

Returning to my mechanic he suggested disconnection of the vehicle battery, leave it to stand for 30 minutes, insert ign key, turn to run position & re connect battery, thus fooling the electronics into a re set. This worked once but didn’t the 2nd time. But on the 2nd occasion the vehicle was left locked & unused for a whole day. Magically when tried the next morning it sprung to life?????

Back to basics, on suggestion of an independent auto electrician, I asked the mechanic to code read the vehicle again. Gearbox codes still stored but the engine ECU shows no fault codes. This I believes narrows the faulting by demonstrating that normal ignition circuits and engine running equipment to be healthy. Further making me believe that its immobiliser related. Once again my mechanic has said that it’s beyond him & the auto electrician has stated that he doesn’t have an in-depth knowledge of Renault electronics or alarm equipment..

Another comment to add, the weather has been dry & not too cold & I haven’t used a hosepipe to wash it, thus eliminating water!

Once again ANY ideas gratefully received…………….
Currently in DavetheIV's garage:
2001 Renault Megane Scenic 2.0 auto
DavetheIV is offline  
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