Harold57

Yes, that is correct.

TarheelNic

Bimmer,
Yes, just read the resistance between those two pins (2 & 6 on the S20 harness) with a multimeter. I wouldn't recommend powering the motor directly (particularly while its shaft is still connected to the car's roof mechanism) ---but I would recommend removing, cleaning (with spray-contact-cleaner), and then re-seating the harness at the motor-end, and at the Roof ECU end.

These are either standard 12V DC motors that they're using pulse-width-modulation to control --- or they are stepper-motors. (I've ordered a spare for my car that should be here early next week --- so that I can see for myself exactly what type DC motor they're using for these.)

The duty cycle and wiring-diagram for the roof motor are shown below. The ECU sends 12V pulses the two motors to make them turn, and the ECU reads the feedback-pulses from both sides to try and keep the two motors (left and right) synchronized, to avoid binding the mechanical linkages.

Hope this helps. Please keep me posted.

_____________________________
2007 SC430
Starfire Pearl/Ecru
Vais SLX w/XM;
NavTool 3.0-HDMI for AppleTV,
BU Camera & BlindSpot Cam.

TarheelNic

my spare roof motor & linkage assembly arrived today, unfortunately it arrived in pieces, with the motor's worm-gear housing broken. just my luck. I think its fair to say I still don't actually have a spare... :-/

Anyway, the motor is a standard 12VDC unit (it's not a stepper motor), so the ECU obviously uses PWM to control the motor's speed.

Bimmer: Here's a photo of the actual motor....

_____________________________
2007 SC430
Starfire Pearl/Ecru
Vais SLX w/XM;
NavTool 3.0-HDMI for AppleTV,
BU Camera & BlindSpot Cam.

Matt169

Update... I took to an independent shop and they diagnosed the left hand side cable was broken. Getting that replaced today.

416tt

iTrader: (1)

Thankyou Tarheel, I didnt get a chance to do it this weekend im hoping to try tomorrow evening. Will keep you posted for sure. should i have the car to 3rd ignition when reading the resistance between 2&6? and sure i will re-seat the connectors, and thanks for the diagram.

hmm so since its not stepper, that means motor is powered until the next switch detects postion? and thats too bad, will the give you a refund if you send back?

Thats good news . Hope there not charging alot, im not sure what "left hand side cable is but you should post a pic incase someone runs into this problem later" also did you have a error code? thanks.

TarheelNic

You're welcome... But No. Disconnect the battery before you remove the the S20 cable harness from the roof ECU to read the resistance.



Correct, or it stops if it senses the two motors aren't turning at the same rate --- Remember, the ECU sends pulses to the two motors; and it measures separate pulses coming back from those two motors, to keep them synchronized.

I'm waiting to hear back from the supplier on the return/replace issue.

rlp1949

I have a low mileage 2002 that's mechanically and physically perfect, except for an intermittent roof issue. I've discussed it in this forum before but not recently. When the issue does occur, my roof closes or opens 99.9% of the way but won't do that last 0.1% and turn off the red light on the button. The button is then unresponsive and I have to stop and start the car to get the button to become responsive again. I thought the car had worked out its issue because it went through 30 or maybe 40 cycles this year without an issue. Then a week or so ago the roof got stuck in two cycles back to back. It scared me enough to start working again on the fix.

I live 2-1/2 hours away from the Bellevue Lexus dealer and convertible roof issues scare away everyone closer to home. I did get my car in to a Toyota dealer when the roof was stuck and got an error code. The DTC error code is B2530, Luggage Front Lock Switch (LH), which I understand is a limit switch. The Lexus dealer knocked me over with the repair estimate. $4,840.72 for the entire hinge assembly and $1,350 installation plus 10% sales tax. Great help on this forum identified the limit switch and the hinge assembly part. The switch was about $100 from Sewell and the entire hinge (used) was $250 on eBay. I bought the eBay hinge.

The dealer won't install a used part; however, he did say that he knew a body shop that worked on these roofs. I have a call into the service advisor to follow up.

I learned through this forum that replacing the hinge requires a jig that's sole purpose is the alignment and replacement of this part. It's fortunate that this complex roof mechanism is pretty darn reliable, considering the cost of the parts and the installation difficulties.

I read in this discussion that someone was able to get an independent shop to work on his roof. Lucky guy.

Of course, I can drive my car without using the top, but that's one of the biggest reasons to own this car!

Harold57

I was able to get an independent shop to work on mine but that shop specializes in Lexus cars. The company was started by Lexus certified mechanics.

Is the switch reasonably easy to remove and replace? If so, consider just swapping out the switch from the new assembly on to the one currently on your car.

rlp1949

Good point. It's possible the switch is accessible without removing the hinge assembly and doing the realignment.

rlp1949

The Lexus service advisor gave me a phone number for a body shop that he would recommend. The body shop said they actually sub out convertible work. He gave me the number for the sub. The sub is unsure whether they've ever worked on an SC roof. He's checking.

If anyone knows of an independent shop like Harold's in the Seattle/Bellevue area, I'd sure appreciate the info. Roof issues with this car are indeed an uncommon specialty.

DshngDaryl

If you are bold and have a "What the heck, it doesn't work anyway attitude, you can try taking a sharpie and tracing out the outline of the hinges on the trunk lid and on the floor pan. Make sure to do all 4. Then get a helper and remove the trunk lid and place it on the floor. Once off, remove the problem hinge and replace the new one exactly in the same place as the old one using the outline. Replace the trunk lid using the said outline.


If all the hinges are built to spec and haven't been twisted or warped in transit, theoretically it should work.

Please know....
I HAVE NOT DONE THIS, SO I DO NOT KNOW IF IT WILL WORK, but think I am going to give it a shot if my motor continues to act up.

416tt

iTrader: (1)

I hope they do replace it!

Thanks alot! Lol I finally got the multimeter so will test it tomorrow but before I do that I have a stupid question, lol what do I set this to?


Thanks again

Scarletti

Ah! Ok, well a long winded step by step explanation then...

The switch positions labelled in Black, with the numbers. The upside down horseshoe icon (Ω) covering all the black positions is the symbol for Ohms, the unit of resistance.

Top left is DC Volts ("V" & solid + dashed line).
Top right is AC Volts ("V" & wavy line).
Bottom right is DC Amps ("A" & solid + dashed line).

Most Digital Multimeters (or DMM for short) only have a few positions and auto set their own values. Yours is rather manual, so you have to set the maximum limit yourself. EG the 2000 Ω positions will let you measure from 0 to 2000Ω. If you use to high a value, it won't show small values (small values will just show as 0 and you'll be led to believe that is correct, but your being fooled by a rounding error).

Anyway, the test you are going to perform is called an "open circuit test".
1. Disconnect battery
2. Set DMM to 2000Ω (I would guess the wire in your loom would read ~ 500Ω, but may be as low as 250Ω or as high as 1000Ω. This is just a function of it's diameter and it's length. The principle being that you select the switch position that best matches the value you're expecting. ( EG to measure a 12v car battery the best choice would use the DC Volts "20" position, the worst choice would be "1000" position. Irrelevant to this test, but used to illustrate how the DMM ought to be used.)
3. Put black probe in the Common (black) terminal and the red probe in the right hand (red) terminal (labelled V.Ω. mA - the left hand terminal is for current and is marked 10A).
4. Connect probes to pins 2 & 6 (doesn't matter which way around, will be the same results either way).

If you see the meters display say OL (some makes/brands might say UL or "1") which stands for Over Limit (some people may say it's Outside Limit). Because you are measuring Resistance, in this context OL means infinite resistance which is an Open Circuit (which means there is a break in the wire).

As you are doing an "Open Circuit" test, you are looking for OL (bad cable, as it has a break in it) or for a value to be displayed by the DMM (doesn't matter what the value is, just means the cable isn't broken... therefore its a good cable as far as this test is concerned).

Repeat the test a few times to ensure you get it right and report back!

Edit: When I wrote the above I had it stuck in my head the Wiring Loom was likely 5M/18Ft long (IE running length of car). In reality it's much less than that as Roof ECU is in the trunk of course. Likely resistance for a sound cable is more like 15-50Ω

416tt

iTrader: (1)

Thank you so much, i will try this today.

oh and i had a seperate question, on the ecu does anyone know what these pins are for on the s19 connecter? i think they are 6, 7, 8

TarheelNic

S19SignalDescription1-BRFRBattery Roof Fuse Right (B+)2- BRFLBattery Roof Fuse Left (B+)3 -BLGRLuggage Fuse Right (B+)4- LFR+Luggage Motor Power (Left)5 -RLM+Roof Lock Motor (Power)6- BLGLLuggage Fuse Left (B+)7-BPTBattery Package-Tray Motor Power (B+)8-CPUB+12V9-E2Body Ground10- E3Body Ground11-E4Body Ground12-LFR-Luggage Motor Power (Left)13-RLM-Luggage Door Detection Switch