Electric Seat Adjustment Failure by rep10



rep10
Rover 75 electric adjustable seat failure fuses ok, connections under seat are correct can anybody suggest something else.

Posted 22 Dec 2016, 18:35 #1 

User avatar
Duncan
Are you sure all the fuses are OK? Is it driver or passenger? Memory or not? Is it all functions or just some? What age of car?

As much detail as you can give helps narrow it down a lot!
Image

Posted 22 Dec 2016, 21:40 #2 


rep10
Thank you Duncan for your reply, I have met you at the club meetings. The car is a Rover 75 V8 Connseur SE 2005, its the driver seat that is the problem, no memory and no functions. The seat is in a useable position but I would like it working properly. 30 amp fuses seem ok. Thanks Richards

Posted 23 Dec 2016, 16:33 #3 

User avatar
Devilish
Need some positive elimination I reckon.

Ensure seat power supply fuses are supplying 12 volts by using a test meter probe on both the supply and load side of the mini blade exposed pins of fuses 49, 51, and 53 while in situ, IGN on.
Image

Are your electric seats retro fitted or original equipment?.

If original, and you stated the seat loom connection is ok, then reach under and unplug the loom.
IGN on
Test thick wires on the loom plug
Black = earth
Yellow = earth
Orange/Yellow = 12v
Orange/Green = 12v
Orange/white = 12v

Thin Slate/Grey = earth

Everything apart from heated seat elements go though the under seat ECU (Engine Control Unit). if there is a power supply problem relating to the ECU none of the motor functions will work.

Next thing I would do is remove the side valance and drive the seat motors direct, bypassing the BCU (Body Control Unit), this will aid removing the seat also. because the seat will not recline, removing the torx screws will be tricky, but I have done it several times, a helping hand to hold the seat cushion out the way helps.

This may help also, only takes a few minutes.

First remove the motor switch covers. Insert screwdriver from above or below a few mm as shown in the pic and lever out until it clicks off. This is the best place to lever off the cover without damaging the microswitch parts underneath the cover.Pull off the switch cover with your fingers.
Image
http://i681.photobucket.com/albums/vv17 ... _UK/4x.jpg

The switch covers click into place by a castleated type turret shown below. Note the cover has to be replaced the same way, be careful not to try to push the cover on upside down.
Image

The valance cover is held in place by 2 X torx screws and a nut with a 10mm head. Recline the seat back as far as it will go and remove the torx screws. The nut is accessed by raising the seat as high as it will go and tilting the front of the base upwards. Reach behind the valance cover and remove the nut. It can usually be removed using only your fingers if you push against the valance, I only tighten it finger tight by pushing against the valance cover. The bolt the nut goes on is held in place though a plastic tube type mount, whammying up with a spanner or socket may damage the bolt mounting.

Take hold of the cover as shown, (torx screw and nut positions arrowed)
Image

Pull the cover away, no need to yank the cover out, there is plenty of room to unplug the switches. the front cover securing bolt can be seen towards the front of the valance cover.

Lever off the plug to the switch module (I use a small screwdriver against the retaining tab)
Image

Same with the memory switch plug
Image
At the module connector in the above picture,
Using a suitable 12v supply and earth, and wires with probes suitable to hold in pin sockets (twisty bits of wire, matches, or cocktail sticks at your own risk
Connect Black pin to earth.

Momentarily Connecting 12v to Yellow/White pin , OR (not both) 12v to White/Yellow pin , will directly power the motor to move the seat forward/back, this will allow access to the seat mounting bolts. Momentarily Connecting 12v to the Yellow/Pink and Pink/Yellow pins will adjust the backrest if needed


Attempt this entirely at your own risk. Any damage caused whatsoever, from blowing fuses to firing airbags or pre tensioners is entirely your own responsibility
If at first you don't succeed, hide the evidence.
Image

Posted 29 Dec 2016, 17:54 #4 

User avatar
Devilish
The memory ECU does more than just remember seat positions.

Under the O/S front seat you have 4 wires in the supply loom, earth, switched earth from the heated seat switch, 12v to heated seats, 12v to motors.

Just connect those 4 wires up to a memory seat and you will get zilch.

I have only removed 2 ECU's and re wired the seat, one had a fault I did not want to go into, the other was bought from a scrappy, dismantler must have dropped or plonked the seat on something, because the ECU looked like it met the head of a lump hammer and was toast.
If at first you don't succeed, hide the evidence.
Image

Posted 30 Dec 2016, 13:43 #5 


rep10
Just want to say a big thank you to Devilish and also Duncan for their help and advice for the problem I had with electric adjustment on my driver side seat. I have not had time to investigate the problem, busy moving house at present. Going to live in Bewdley. Many thanks Richard

Posted 08 Jan 2017, 17:03 #6 

User avatar
Devilish
I wired up a set for someone the weekend, the memory ecu casing looked like a banana, reckon something got stuffed under the seat, the seat got moved back, and tried to rip the ecu from the seat, amazed the PCB (Printed Circuit Board) was in tact and it worked.

Forgot to mention at the seat loom connector, one of the thin wires to the ecu should have 12v, forgot the colour and cant find my cd. My daughter thinks she is taking over my study now I am retired, I soon told her.
If at first you don't succeed, hide the evidence.
Image

Posted 09 Jan 2017, 22:08 #7 

User avatar
Trebor
Yes you told her you wanted to book an appointment to go back in !
Robs Pictures at :

Robs Car Gallery

click below to access nano website
Image

Planning is an unnatural process, much better to just get on with things, that way failure comes as a complete surprise instead of being preceeded by a period of worry and doubt

Posted 09 Jan 2017, 23:04 #8 


Top