Yaris 2016 Driver Window Malfunction

[DSAL]

 

Thank you for taking the time to read this. I have an issue with my Yaris 2016 which I hope someone can help me with.

I have tried to summarise below: 

Vehicle/System:

• Yaris 2016 RHD.
• Driver side window with "auto" function.  10-pin window motor (on LIN?) 

Issue:

• Driver side window stopped working (closed). 
• Motor occasionally makes a faint noise when trying to operate but no action. 
• Passenger side window OK. Both from master switch and individual switch. 

Investigation: 

• Master switch checked with multimeter for continuity/correct operation. All OK.  
• Fuse OK. 
• 3 different motors tried - issue still exists.
• I'm unable to find this motor new anywhere but I feel it's highly unlikely all the used ones I received (from different sellers) all have the same defect. 

 

Can anyone suggest anything else to check before I bite the bullet and the car to the main dealer (who reckons it's the motor and wanted £400+ to replace)?

Thank you 🙂

[Starensis]

Have you checked power at motor? The switch reverses polarity for up/down operation.

if you have switched power ( including earth ) at motor, then it’s motor and/or lift mechanism. Is the glass wedged somehow in frame? Does glass slide up/down glass channel freely? Be worth taking glass out and trying motor without it attached.

[DSAL]

15 minutes ago, Starensis said:

Have you checked power at motor? The switch reverses polarity for up/down operation.

if you have switched power ( including earth ) at motor, then it’s motor and/or lift mechanism. Is the glass wedged somehow in frame? Does glass slide up/down glass channel freely? Be worth taking glass out and trying motor without it attached.

Thank you for the reply.

I have tested the motor(s) without the regulator assembly and still had the issue so it's definitely not related to the window mechanism.

Yes, power does reverse at the motor when the switch is pulled/pressed.

From everything I've checked so far, it does seem to be an issue with the motor. I just find it hard to believe that I ended up with 3 bad motors (4 if we include the original!) so I was just wondering if I might be missing anything obvious.

[Starensis]

47 minutes ago, DSAL said:

Thank you for the reply.

I have tested the motor(s) without the regulator assembly and still had the issue so it's definitely not related to the window mechanism.

Yes, power does reverse at the motor when the switch is pulled/pressed.

From everything I've checked so far, it does seem to be an issue with the motor. I just find it hard to believe that I ended up with 3 bad motors (4 if we include the original!) so I was just wondering if I might be missing anything obvious.

If you have power and earth at motor, then it has to be motor. Are you getting 12v? Motors do have sensors built in for anti-trap function, plus to tell system window is open.

Passenger window is OK you say?

[flash22]

You have a control side and also power direct to the motor, so 2 fuses, iirc 30 amp supply and one for the control side

you say the voltage changes when you press the switch that is the control side do you have power to the motor, the 2 fatter wirers

 

PW-RHD yaris.pdf

PW-RHD.pdf

[DSAL]

2 hours ago, flash22 said:

You have a control side and also power direct to the motor, so 2 fuses, iirc 30 amp supply and one for the control side

you say the voltage changes when you press the switch that is the control side do you have power to the motor, the 2 fatter wirers

 

PW-RHD yaris.pdf 22.86 kB · 1 download

PW-RHD.pdf 19.21 kB · 1 download

Thank you very much for the diagram. This validates the information that I have been able to establish by physically tracing the switch PCB layout and checking continuity between connectors.

Yes, it's the control side that changes polarity (red and green wires). The 2 fatter wires have 12v "permanent" power (when ignition is on).

Interestingly, I noticed today that there's sometimes a significant voltage drop on the 2 permanent power wires at the motor when operating the switch. Could this be indicative of the motor stalling and therefore evidence of a bad motor? Or could it be something else on the vehicle side?

[flash22]

If you have a broken or partly broken wire somewhere (hint, between the car and door in the rubber) it may have the correct voltage but not enough current to power the motor

I would check the resistance of each power wire between the motor and the door loom plug behind the driver's kick panel (everything unplugged) - also check for corrosion in the connectors - use a jumper wire from the motor ground to somewhere on the body (not the door)

also check the ground junction in the door loom if you can find it

[DSAL]

2 hours ago, flash22 said:

If you have a broken or partly broken wire somewhere (hint, between the car and door in the rubber) it may have the correct voltage but not enough current to power the motor

I would check the resistance of each power wire between the motor and the door loom plug behind the driver's kick panel (everything unplugged) - also check for corrosion in the connectors - use a jumper wire from the motor ground to somewhere on the body (not the door)

also check the ground junction in the door loom if you can find it

Thank you so much! You've solved the puzzle!

I started by measuring the resistance of the power wire as suggested, and to my surprise found it to be in the mega ohms! Touching the rubber between the car and door caused significant fluctuation in the reading. I managed to find a position that gave a reading as close to 0 ohms as possible and tried the window switch. And lo and behold - motor started spinning!

So now with the culprit found - how big of a job is it to replace the door loom? Or is it feasible to change the bad wire only?

Thanks again for the great help!

 

[Starensis]

You could splice it, but may make it more vulnerable to breaking again. If you run a cable inside door or car and splice there, it would be better. You may also find a couple more wires ready to break, so check the lot.

[flash22]

You can splice in a new section soldered or open crimped and heat shrink

looms are a bit tricky, you need to pop the rubber off the car side feed the plug out, the loom in the door it's held by loom brackets (loom former) the tricky bit it getting the loom around the front window runner - the runners are a tad sharp too - don't ask

[MikeSh]

1 hour ago, Starensis said:

You may also find a couple more wires ready to break, so check the lot.

The thicker, higher current, wires will be the first to fatigue, so hopefully the only other one would be the ground wire. Might be worth 'fixing' that while sorting the window feed.

[DSAL]

Thanks everyone. I have never done a wiring repair in a similar area, so apologies for the basic questions.

I'm just wondering what the best method is to expose the wires within the rubber sleeve for inspection and to carry out the repair in the tight area between the door and body.

Alternatively, I may try to run a couple of wires through the sleeve/grommet and splice on the car and the door side as suggested (not sure how straightforward the run is), but I would still like to inspect the rest of the loom within the rubber sleeve. 

Appreciate the guidance 😊

[flash22]

Don't repair the break, splice in a new section say 300-400mm long from the plug in the car, as i said above it's a tight bend as it enters the door and goes around the runner

it may be easier to swap the loom be aware there are a few types so you will need the part number off the loom - toyota will want an arm, a leg and your firstborn if available

[DSAL]

1 hour ago, flash22 said:

Don't repair the break, splice in a new section say 300-400mm long from the plug in the car, as i said above it's a tight bend as it enters the door and goes around the runner

it may be easier to swap the loom be aware there are a few types so you will need the part number off the loom - toyota will want an arm, a leg and your firstborn if available

Thank you.

I think the point that's still not clear to me is how to "fish" the wire from the car through the rubber into the door (or vice versa). Maybe it will become more clear once I actually try to do it in the weekend. 

[flash22]

The rubber is just a tube, it is easier to disconnect the plugs in the car, pull the rubber back both on the door and the car, think of the rubber as a sweet tied at both ends

Example door loom - you may be able to visualize the job better

https://www.ebay.co.uk/itm/274583707970

https://www.ebay.co.uk/itm/203158056563

 

[DSAL]

So I need to remove the loom in any case? I was under the impression that I could run the repair wire from the car or door side without removing the loom, hence my confusion. 

[flash22]

You could, but it's all a bit tight and fiddly - you will see when you go to look at it