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MG MGF Technical - Steptronic wont start

Hi all, this is my first post, hope someone can help with a problem I have on my MGF Steptronic.
Recently returned from holiday to a flat battery (the car had been standing for 3 wks prior to that). I recharged the battery and reconnected it. As soon as the neg terminal was connected the alarm started sounding continuously. From past experience if I remember correctly the alarm normally gave one bleep only. The only way I could stop the alarm was to disconnect the Neg terminal again, the key fob had no effect. On the third attempt at connecting the Neg terminal the alarm stayed silent but when I tried to start the engine nothing happened not even a clunk or chatter from the starter solenoid. All dashboard lights illuminated and extinguished as normal. I have checked all engine bay and main fuse box fuses as well as the stand alone fuse that protects the steptronic gearbox - all are OK. Not knowing which or where the starter relay is I have removed and tested the Yellow relay from the engine bay as well as the yellow relay to the side of the main fuse box (don't know what the Red relay is for) - both operate OK.
It is as if the car is in the park mode or has the immobiliser permanently engaged. While I had my head in the engine bay I noted a low hum which starts when the ignition switch is set to position II and can only be silenced by disconnecting the battery NEG terminal.
Any help would be greatly appreciated
s Richardson

It is likely that your fob may need to resynchronise with the immobiliser since the power down. If so, all you need to do is press either one of the fob buttons rapidly (eg 1 second interval) half a dozen times in succession while standing close to the car.
Give that a try first and report back...
Charless

... and it might not be only the car's battery that had flattened - if the re-sync Charles suggests doesn't do the trick, try the other keyfob (if available) or fit a fresh battery in the keyfob & try the sync process again.

The car battery, having spent a period completely flat, is best regarded as 'suspect' - the capacity will have been reduced, by how much is hard to say but erring on the side of caution and scheduling a new battery fairly soon will save you finding out the frustrating way. My spies inform me that entering promo code Battery15 in the Euro Car Parts site results in a Bosch Silver 3yr warranty battery arriving at your door for £35 odd - bargain I thought as I ordered 2...
bandit

Hi guys, thanks for your speedy responses unfortunately I omitted a couple of things, which has probably lead to me feeding you a red herring. I omitted to say the battery is relatively new (10 Months)and more importantly that the fob works OK. I can set and unset the alarm with it, plus the alarm operates if triggered. So am I looking in the wrong area when I suggested an immobiliser problem.
s Richardson

Have you tried with the gearlever in both P and N ??
Geoff F.
Geoff Farthing

When you unlock & disarm the alarm with the keyfob, does the red LED extinguish or continue flashing? If it extinguishes, indicating that the ECU regards the car to be un-immobilised, but the starting circuit is still disabled, then suspicion would lie with something in the gear selector area. I forget which positions of the lever will and won't allow engine starting, but would it be fair to say the car is behaving as if you weren't following 'correct' procedure for engine starting, even though you are?
bandit

Hi Geoff, yes I've tried that. Because the alarm sounded continuously I'm assuming the fault lies with the immobiliser but is my thinking wrong? Could the problem with the alarm sounding be a coincidence and it is in fact just a bog standard starter fault? Can anyone tell me where the starter relay is located, is it any of the ones I mentioned in my fist post or is it located somewhere else? If I can find and test this I will know that the fault either lies with it or between it and the starter motor. How accessible is the starter motor? Again any help would be greatly appreciated.
s Richardson

Sorry bandit I was replying to geoff, hadn't seen your post come in. Yes the LED behaves normally - flashes rapidly when keyfob is pressed, then settles down to a regular flash when the alarm is set and extinguishes when it is disarmed with the keyfob. The alarm can be set regardless of the gear stick position but car can only be started if the gear selector is in either P or N position.
s Richardson

The starter motor is visible through the grille aperture, just to the left of the engine block & above the gearbox. The small cylindrical object on the side of the starter motor is the solenoid, which may be stuck - giving it several sharp taps with a heavy object may serve to free it up. That's one of the more likely causes, bearing in mind the car hasn't moved for a few weeks. The starter relay is usually reliable, so much so I'm not sure about its location - behind the ECU in the grille aperture I suspect. If a sharp tap or two on the starter solenoid doesn't do the trick, have someone try to start while you listen in the ECU area, identify anything that is giving a 'click' and report back...
bandit

Call me stupid if you will but with respect to the starter motor location, I have removed the grille itself but cannot see anything that looks like it. Is the set up on the steptronic different? To the left of the engine there is a rectangular plastic box that is ducted to the inlet manifold I assume this is the air box? Whatever it is it obscures my view of the gearbox. I could upload a photo to show what I mean. Is there any point in jacking the car up and going at it from below? Regarding the clicking - yes when the key is turned to start there is a single click from the area of the ECU and again when the key is turned off. Is this the starter relay making and breaking?
s Richardson

Ah, was forgetting yours is a Steptronic, sorry... Ought to be visible from below if you jack up the NSR corner, but you may need to remove the NSR wheel and the closing panel in the back of the wheelarch to get a good look / access to administer the sharp blow to the solenoid casing.

The clicking in the area of the ECU would suggest the relay is functioning, so a stuck solenoid on the starter is definitely the most likely issue.
bandit

Thanks to all contributors, the F is purring like a good en again. You were right on both counts, the starter relay is located behind the ECU and it was a jammed solenoid. Knowing where the starter relay was allowed me to pull the connector off and do a volts check to confirm voltage was reaching that far. With that confirmed I went in search of the starter motor, which on the steptronic by the way is on the bottom left of the engine, looking in at the NSR wheel arch. After cleaning the starter solenoid connector which was slightly corroded and a couple of difficult to administer(due to its location)sharp blows to the solenoid the problem was sorted.
Thanks again.
s Richardson

Score 1 for the Clarkson school of mechanical repairs - hit it with a hammer, that's bound to fix it 8-)
bandit

For the Techies.
The Solenoid was percussed.
Geoff.F
Geoff Farthing

This thread was discussed between 13/01/2012 and 21/01/2012

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