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Disco 3 Auto

Would you believe it. Auto box wouldn't change up or at least not every time it should have. Was in dealers for a few days to sort out, since it would have been dangerous to drive. Guess what! It turned out to be an incorrect wattage bulb fitted a few days earlier in the rear light cluster. The fault not happening when lights were off, and the garage did all the testing in daylight running. It only came to 'light' when some 'bright spark' in the trade had come across this before. Switched the lights on and tested on a run, and the fault occurred, auto box wouldn't change gear. After fitting the correct wattage bulb, all is well. So now we all know how to fix it. Gordon

Reply to
Spanner
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Spanner uttered summat worrerz funny about:

I read as far as wouldn't change and related it to my RRIII. First car I've had that won't let you out of park unless your foot is on the brake. My immediate thought was tail lights.. as I read on I deffed it out but for once my gut feeling was right! Spooky - should I be looking towards another marque / challenge :-)

Lee D

Reply to
Lee_D

What make and model of box is fitted to a Disco 3? Electronically controlled ZF boxes are sensitive to line voltage feeding their ECU - if it drops below a certain limit they go into limp home mode. It's sometimes the first warning you get of a faulty charging system if the no charge light doesn't come on.

I'd be interested to know the explanation of how a wrong bulb in a taillight could cause problems, though.

Reply to
Dave Plowman (News)

Something to do with multi-plexing [1] the wiring, I believe. I think new Renaults also have a similar 'issue'.

Just need to make sure the right bulbs are fitted ... ;)

[1] There was a thread, which I think was on here but might have been in a n other group, that told chapter and verse of why it happens. Summat about relative voltage drops compared to a datum (standard bulbs) when diffferent bulbs are used. Long while ago ...
Reply to
Paul - xxx

There can be issues with the bulb failure unit with out of spec bulbs - the failure sensor constantly monitors them on or off by pulsing and checking. But it's a strange design which allows this to interfere with a totally non related circuit. Designed by MS?

Reply to
Dave Plowman (News)

Nah, just a "Solihull CAN-Bus", Dave. Badger.

Reply to
Badger

My 1997 Ford Exploder did the same thing. Took an AA man to figure it out - I couldn't get the lever out of Park.

Reply to
David Millen

Typo corrected.

Reply to
Rich B

Didn't know there was a Ford Exploder

Reply to
Spanner

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