Auto-box probs.

[mr.man]

Hi Guys,my E39 528i auto-box has developed a problem in as much as it does not change up into a higher gear after using a bit of power such as overtaking. Bit of a pain with engine spinning at 6500 revs. and not changing up into a higher gear. I have to flick across into tiptronic mode and change up that way.
In normal driving it works perfectly so I can't believe it's too serious a fault. I'm guessing there's an
electrical signal between the accelerator control and the gearbox that's malfunctioning.
Hoping Blackspider can help. Cheers.

[mr.man]

StuB said:

Tyres are possible, the wheel speed sensors feed the brain that controls the box and if it thinks you're cornering (like if your tyres are of different circumference), it wont change. Did you recently replace a rear tyre?

Got me thinking now,replaced both rear tyres about 2000-3000 miles ago. The car has had Inspection 1 service since then and the dealer commented on a bit of un-even tyre wear on one of the front tyres. Where is/are the speed sensors?

[mr.man]

Just had the car up on the lift at the local Tyre&Exhaust centre.
Nothing wrong.All the tyres are evenly worn. Plan B it is then.

[mr.man]

The plot thickens..........Driving along normaly tonight and out of the blue two bright yellow warning lights appear on the dash. ASC and ABS together. Looking like a wheel sensor failure (or a poor connection or something amiss on the ignition switch). Any input please Mr Blackspider would be much appreciated.

Edited by mr.man on Monday 21st May 23:09

[mr.man]

robertsafc said:

hi, did you solve your problem with them yellow lights coming on. mine has just done the same tonight. thanks
rob

Yes. Wheel sensor replaced,off-side front. Cured immediately.

The wheel sensor is also the ABS sensor hence the lights.