Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E36 (1991 - 1999)

E36 (1991 - 1999)
The E36 chassis 3-Series BMW was a huge hit among driving enthusiasts from the first moment the car hit the pavement. The E36 won numerous awards over the years it was produced and is still a favorite of many BMW enthusiasts to this day! -- View the E36 Wiki

Reply
 
Thread Tools Display Modes
  #1  
Old 04-26-2014, 07:35 AM
JMF56 JMF56 is offline
Registered User
Location: Chicago, IL
 
Join Date: Apr 2014
Posts: 4
Mein Auto: 98 328ic, 96 328i
Cannot synch top - DIS reports lid motor shorted to ground

I've been fighting an non-operational top for a few weeks now and am at the point of where I am out of ideas. I'm hoping someone can shed some light on what might be going on.

Background
1/98 328ic Fully automatic top
Purchased the car late last year, top did work once then quit.

What I know/ have done
Tried doing the synch process with the top stowed, no motors will active, switch led blinks.
Checked all fuses: ok

Hooked up DIS and read fault codes and status:

Fault code I am seeing is: Code 1 - Motor Outputs Short Circuit to Ground. MOLID1 & MOLID2. I'm assuming 1 & 2 refers to motor outputs (Pins 9 and 5 on the CVM)

I did a Status Check with DIS both with the top open/stowed and with the top up/locked. Terminology is as reported by DIS.

Top Down and Stowed
S1:Open
S2:Open
S3: Top Stored: Yes
S4: (Not Fitted in Automatic)
S5: Closed
S7: Open - Not locked
S8: Closed - Top Unlocked

Lid Motor M100: Off
Top Motor M101: Off
Hall Sensor: bar graph shows "closed"

Top Up and Locked
S1:Open
S2:Open
S3: Top Stored: No
S4: (Not Fitted in Automatic)
S5: Closed
S7: Closed - Locked
S8: Open - Not Unlocked

Lid Motor M100: Off
Top Motor M101: Off
Hall Sensor: bar graph shows "closed"

As far as I have read and understand al the microswitches are correct.



I've disconnected the connectors at the motors and measured the resistance to ground and measured open. I measured each motor resistance:
Top Lid Motor: 1.2 ohms
Top Motor: 1.7 ohms

Can someone confirm this is normal?

Verified that there is not any conductivity between each of the motor terminals and the metal case of the motor, so this would rule out a direct short to ground.

I am able to power the motors directly by using a battery (tested both at the motor and at disconnected X13156 at CVM). Motors were disconnected from gears. Ran for several minutes ok, in both directions. Measured current draw:
Top Lid Motor: 1.4A
Top Motor: 1.0A

Verified wiring from CVM to motors: ok

Tried running motors from DIS (there is an entry in DIS to do this, but it appears to be only for the top motor): no response from motor, but sets the same fault code.

Replaced CVM with identical part number from ebay, same issue. I'm assuming ebay CVM is good.

At this point, Im wondering if the lid motor is bad. Just dont know if the resistance I measured is acceptable or is that triggering the CVM to think it is shorted.

Thanks is advance for any insight...

Jeff

Last edited by JMF56; 04-26-2014 at 02:19 PM. Reason: added clarification
Reply With Quote
Advertisement
  #2  
Old 04-26-2014, 08:19 AM
CitizenOfDreams CitizenOfDreams is offline
Officially Welcomed to the 'Fest
Location: Orlando, FL
 
Join Date: Aug 2013
Posts: 953
Mein Auto: 1998 BMW 740i
Have you measured the resistance between the motor leads and the ground? The motor may have an internal short to the case.
Reply With Quote
  #3  
Old 04-26-2014, 10:46 AM
JMF56 JMF56 is offline
Registered User
Location: Chicago, IL
 
Join Date: Apr 2014
Posts: 4
Mein Auto: 98 328ic, 96 328i
Good point, but I just remeasured that again and it shows its open. I even engaged and disengaged it from the gear, still the same.

Thanks for the suggestion though
Reply With Quote
  #4  
Old 04-26-2014, 02:38 PM
dc_wright's Avatar
dc_wright dc_wright is online now
bimmerfest Supporting Member
Location: Orlando, Florida
 
Join Date: Nov 2007
Posts: 7,252
Send a message via ICQ to dc_wright
Mein Auto: '96 328iC, '04 325Ci
Have you released the motors and moved the top manually to verify there's no mechanical binding?

Also, try checking from the motor connector to chassis on the connector that comes from the CVM to see if you see a short there. If that's good then either your eBay CVM is bad or your motor......
__________________
2006 Z4 3.0si Sport Package (But I'll still hang with my "homies" in the E36 forum)
Reply With Quote
  #5  
Old 04-26-2014, 05:08 PM
JMF56 JMF56 is offline
Registered User
Location: Chicago, IL
 
Join Date: Apr 2014
Posts: 4
Mein Auto: 98 328ic, 96 328i
I've verified that there are no shorts to ground (or each other) on the cable that comes from the CVM to feed the motors (X13156).

Tried doing a synch with the motors disengaged, no motor movement.

DIS has a motor test that spins the disengaged motors for 1 second clockwise or counter-clockwise, depending on which of the two tests you pick. No movement.

I am able to move the top thru the entire range without much difficulty.

As far as the ebay CVM, it is operating identical to my original one, so either their both bad or it is a motor(s)...


I think the next test I'll perform is the DIS motor spin test with no motors plugged in and my DVM connected to see if the CVM is sending voltage....

Thanks...
Reply With Quote
  #6  
Old 04-28-2014, 04:48 AM
JMF56 JMF56 is offline
Registered User
Location: Chicago, IL
 
Join Date: Apr 2014
Posts: 4
Mein Auto: 98 328ic, 96 328i
Hooked up DIS again, cleared faults, pulled motor connectors, hooked my DVM into lead coming from CVM to motor and re-ran the 1 second motor spin test: no voltage being read from CVM to motor.

Maybe both CVMs are bad (bad output stage?)

Jeff
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E36 (1991 - 1999)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 06:19 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms