Front Passenger Seat Stuck in Forward Position

Is the fore/aft motor or the recline motor running? The potentiometer is only for recline (see Item 11 in the diagram below). The fore/aft motor and the other motors have inbuilt Hall sensors for position feedback.

I'm guessing the upholsterers don't have the knowledge to fix what they broke.

I'm not overly familiar with the controls. Do you need to manually tilt the seat to its fully forward position before it triggers the forward movement of the seat base?

There are 3 microswitches associated with the seat tilt (easy entry system). One, I believe triggers forward motion of the seat.. i.e. switch 3M.

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Having said that, the WSM does say that the motor should stop running if it hits an obstacle. I assume this includes the seat track endstops.

Anyway, make sure these switches haven't been squashed with the new seat leather.

I have a wiring diagram for the driver's seat, but the passenger seat should be similar.

Experts?

 

I meant to say, what happens on the driver's side when you do this?

Good question. The recline motor is Item 8 in the graphic above. Since access is limited, I guess you would only know by sticking a stethoscope or plastic tube to the motor and your ear. There are two fore/aft motors in series (Item 11).

I think this issue has happened before. Maybe try searching this forum.

 

And when is the motor triggered? As soon as you push the manual release button or when the seat back is at a certain angle? Is the decline assisted with a motor?

Have you tried pushing the memory switches on the faulty seat? Do you have any saved settings?

 

I'm trying to establish what is normal. i.e. what is the behaviour on the driver's side. This may tell us which components are faulty on the passenger side.

 

I think something has been lost in translation. What is the driver's seat doing. "Nothing"? Or is it working normally? What is normal?

When is the driver's seat forward motion triggered ... when the easy entry knob is moved or when the seat is at a certain angle? Is the tilt asssisted by a motor?

When does the driver's seat stop moving (at the forward endstop or short of the endstop, perhaps at a position programmed by you or the factory). Does the recline motor and the fore/aft motor operate simultaneously after being triggered?

 

Just to clarify... (Sorry, I had to edit my last question). Does the Easy Entry knob cause the tilt motor to assist the tilting of the seat. The microswitches involved in this system have caused issues before. I'm more concerned about the Easy Entry automatics, not the operation of the buttons on the seat base. I would hope that the upholsterers wouldn't have damaged the manual seat controls (although I don't want to rule that out completely).

If you saw that the Easy Entry seat movement was going to crush something, how would you stop it? Can it be stopped by letting go of the Easy Entry knob or can't the seat forward motion be stopped?

 

Thanks. That gives us something to work with.

What do you mean by "usually"? Do you mean there are times when they don't move separately (when the seats are working normally)?

456M owners: I’m trying to establish what is normal operation for the Easy Entry function.

When is the driver's seat forward motion triggered ... when the Easy Entry knob is immediately moved or when the seat is at a certain angle? Is the tilt asssisted by a motor during Easy Entry operation?

When does the driver's seat stop moving during Easy Entry operation (at the forward endstop or short of the endstop, perhaps at a position programmed by you or the factory). If the recline motor is activated during Easy Entry operation, does the recline motor and the fore/aft motor operate simultaneously after being triggered?

During Easy Entry operation, when does the driver's seat stop moving (at the forward endstop or short of the endstop, perhaps at a position programmed by you or the factory). Does the recline motor and the fore/aft motor operate simultaneously after being triggered?

How is the seat returned to the normal position after Easy Entry operation? Is the Easy Entry knob pushed in the opposite direction (if that is possible)? Again, is the recline motor activated? Do you have to keep your finger on the Easy Entry knob to control the movement (for recline and aft movement). If the sequence is automatic, how do you stop the seat moving during Easy Entry operation if, say, your seat starts to crush something in the footwell or behind the seat?

I'm trying to understand why there are 3 microswitches AND a potentiometer in the seat back recline system and whether or not the potentiometer is involved in the Easy Entry operation. The potentiometer may be involved in returning the seat to its original position (assuming it does go back to the original position).

Driver's seat wiring diagram here:

https://www.dropbox.com/t/yBW7U7bJtXJVfNdS

 

Here's what is supposed to happen (although it still doesn't quite explain microswitch operation)

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Because of that last paragraph, lever E seems to have electrical as well as mechanical properties. However, there are no microswitches shown in the wiring diagram for this lever.... The microswitches in the parts manual are shown at the bottom of the seat back.

Does the lever only move in one direction?

Is the sentence "press again lever E or use the adjustment pushbuttons to allow the seat to complete its movement" only refer to when the seat is mechanically blocked?

I assume the rear safety threshold is set up by the factory with an SD tool.

 

The diagram in post #2 shows the approximate location. I only have a photo of switch 1M

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I just realised there is a cable drive from the Easy Access lever "E" to the microswitch.

Is it obvious how to get the leather coverplates off? I would at least try to inspect these switches before paying $$$

 

Here's a shot of the back of the seat showing, I'm told, the potentiometer:

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You can buy repair kits for these on eBay

 

The orange things....

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... but they may be other colours.

Since leatherwork has been done, I would be looking for leather jamming the cam attached to the cable or leather interfering with the microswitch arms.

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It would be great if you could get a photo of the other side, but the centre console might make it difficult.

 

I don't think I have any photos of the ECU (mounted to the 456M seat). Here's a 456 ECU (with the seat lifted):

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Doesn't look easy to get to.

 

Just found this photo in my archives

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The ECU looks very difficult to get to unless you can raise the back of the seat base.