Need Help! Can't figure out electrical issue

[///Monty]

Originally Posted by tom @ eas

Easy way to spot a failed FRM usually will result in no window operation & no response to highbeams pulling back on the stalk. Also angel eyes will both be off.

If wipers are stuck on, likely you have a failed JBBF module (underneath glovebox).

Already checked the wiper module. It's fine. Windows and lights work. I have aftermarket raptor eyes from.OSS Designs

[BPMSport]

Sounds to me like a faulty SZL. The SZL when unplugged or unable to communicate can cause the wipers to wipe indefinitely.

Definitely does not sound like a faulty footwell module.

Check the connections at the SZL and ensure proper resistance and voltage. If these check out, replace the SZL. If a new or used SZL stops the wipers, you'll just need to have it programmed and will be good to go.

It's expected that the turn signal cancel functionality and DSC errors would follow pulling any associated fuses and/or relays.

If reinserting them and clearing faults does not restore turn signal cancelling, this would be another sign of a faulty SZL (provided you are still using the original unit). Replacement of the SZL would cause a number of faults that would be rectified after proper programming.

Water ingress can certainly cause a number of issues depending on the location and severity. The first thing to rule out here is whether any control modules became wet and whether there is a power/ground/resistance issue or damaged circuit as a result.

We have the SZL in stock and can program and calibrate it remotely if needed.

[deansbimmer]

FRM....JBE...SZL.... There are a few more potential culprits if anyone else wants to get in on the action?

Joking aside... If you're not going to take it anywhere, get hooked up with Rheingold, run vehicle test for faults, and run the test plans. Aside from guessing and throwing parts at it, there's really nothing productive to do until that happens.

[///Monty]

Originally Posted by deansbimmer

FRM....JBE...SZL.... There are a few more potential culprits if anyone else wants to get in on the action?

Joking aside... If you're not going to take it anywhere, get hooked up with Rheingold, run vehicle test for faults, and run the test plans. Aside from guessing and throwing parts at it, there's really nothing productive to do until that happens.

Yeah, it is a bit of wash lol. Sucks I'm so far from a dealership. Are you familiar with anyone reputable I can have remotely test it? For the quotes I've asked from different places based on labor and parts, it almost feels it would be safer/better to trade in for something new

[deansbimmer]

Originally Posted by ///Monty

Yeah, it is a bit of wash lol. Sucks I'm so far from a dealership. Are you familiar with anyone reputable I can have remotely test it? For the quotes I've asked from different places based on labor and parts, it almost feels it would be safer/better to trade in for something new

Try Mike Benvo, BPMSport above. He can do lots of fun stuff remotely. He'd be your best shot and may or may not be able to provide the cable to connect to your car.

If you don't have access to a BMW shop and you aren't equipped with the resources to do your own service then yes, perhaps any out of warranty BMW might not be the best choice of vehicle.

[Zertag01]

///Monty...Did you replace Bank 1 and Bank 2 Throttle body actuators yourself. Sounds like the wires to the Throttle body actuators needs to be check again. These Throttle actuators will cause a lot of error messages, especially DSC error

[///Monty]

Originally Posted by Zertag01

///Monty...Did you replace Bank 1 and Bank 2 Throttle body actuators yourself. Sounds like the wires to the Throttle body actuators needs to be check again. These Throttle actuators will cause a lot of error messages, especially DSC error

No, they were professionally installed. However, I am highly doubtful of either being the cause here, as there were no DSC issues until I started pulling fuses to test the wiper issue

[Zertag01]

///Monty...You can also contact Mr. Joseph J (codemyride@gmail.com) he is very good with INPA software, he can possible help you to troubleshoot the error remotely.

[///Monty]

Originally Posted by Zertag01

///Monty...You can also contact Mr. Joseph J (codemyride@gmail.com) he is very good with INPA software, he can possible help you to troubleshoot the error remotely.

Thanks Zertag, I’ve actually emailed him in the past, as I seem to have his contact info saved. I sent him an email from your recommendation. Thanks!

[Richbot]

I don't remember if auto cancel and wipers were borked when my SZL needed to be cleaned, but got DSC/ABS/hill start/yada faults all at once at 50,034 miles (thanks BMW warranty doomsday clock!)

Did some searching, found some had found the plastic ring the SZL uses to sense position could get dirty with some sort of gloop that it is theorized accumulated during production and then crystallizes causing it to lose track of position and throw a fault.

Pulled airbag and steering wheel, (VERY CAREFULLY) cleaned the SZL ring (ALSO VERY CAREFULLY), replaced, I'm at 114,000 miles and no further faults knock sycamore anthracite

It worked in my case, obviously proper diagnostics are better but at the time I was lookinga t a minimum $150 in diag time just to check it, so I figured why the hell not try it and learn something and if it didn't work, no harm. Ended up costing <$1 in shop towels qtips and acetone...props to BMW for indexing everything so I couldn't accidentally install it upside down or something

EDIT: here's the thread. I didn't have to take it apart further or solder anything, just cleaned teh ring

https://www.m3post.com/forums/showth...&highlight=szl

[///Monty]

Originally Posted by Richbot

I don't remember if auto cancel and wipers were borked when my SZL needed to be cleaned, but got DSC/ABS/hill start/yada faults all at once at 50,034 miles (thanks BMW warranty doomsday clock!)

Did some searching, found some had found the plastic ring the SZL uses to sense position could get dirty with some sort of gloop that it is theorized accumulated during production and then crystallizes causing it to lose track of position and throw a fault.

Pulled airbag and steering wheel, (VERY CAREFULLY) cleaned the SZL ring (ALSO VERY CAREFULLY), replaced, I'm at 114,000 miles and no further faults knock sycamore anthracite

It worked in my case, obviously proper diagnostics are better but at the time I was lookinga t a minimum $150 in diag time just to check it, so I figured why the hell not try it and learn something and if it didn't work, no harm. Ended up costing <$1 in shop towels qtips and acetone...props to BMW for indexing everything so I couldn't accidentally install it upside down or something

EDIT: here's the thread. I didn't have to take it apart further or solder anything, just cleaned teh ring

https://www.m3post.com/forums/showth...&highlight=szl

Read his post. I’ll try this after I talk to one of the guys on the forums here for a diagnosis. Thanks man!

[///Monty]

Originally Posted by BPMSport

Sounds to me like a faulty SZL. The SZL when unplugged or unable to communicate can cause the wipers to wipe indefinitely.

Definitely does not sound like a faulty footwell module.

Check the connections at the SZL and ensure proper resistance and voltage. If these check out, replace the SZL. If a new or used SZL stops the wipers, you'll just need to have it programmed and will be good to go.

It's expected that the turn signal cancel functionality and DSC errors would follow pulling any associated fuses and/or relays.

If reinserting them and clearing faults does not restore turn signal cancelling, this would be another sign of a faulty SZL (provided you are still using the original unit). Replacement of the SZL would cause a number of faults that would be rectified after proper programming.

Water ingress can certainly cause a number of issues depending on the location and severity. The first thing to rule out here is whether any control modules became wet and whether there is a power/ground/resistance issue or damaged circuit as a result.

We have the SZL in stock and can program and calibrate it remotely if needed.

Originally Posted by deansbimmer

Try Mike Benvo, BPMSport above. He can do lots of fun stuff remotely. He'd be your best shot and may or may not be able to provide the cable to connect to your car.

If you don't have access to a BMW shop and you aren't equipped with the resources to do your own service then yes, perhaps any out of warranty BMW might not be the best choice of vehicle.

Sorry to revive something a little old that you may not remember, but hopefully I can add some new info that I can steal your expertise for again.

Lucked out and had a recall for the blower motor wiring harness, so I took the opportunity to drop my m3 off at a service center (Passport BMW, Maryland).

With the prior issues, they agreed to take a (long) look and make sure that it was not related to any shorts in the wiring harness, etc. After replacing the harness and finishing the recall, and much due diligence, they originally quoted me a price for SZL replacement because they thought that was the issue.

Then eventually called me and told me (with a great deal of certainty; not sure if I believe), that the codes they receive have them believe it is a failure with the DSC module, not SZL. Now, I assume they mean the ABS DSC Pump module, which I can find many on eBay for $100-$500. They quoted me $4,000 for this job...

Also, considering the water leak issus and moisture (now fixed), is it possible it could be the speed sensor under the driver seat?

DSC Part Number: 3451-7841232-01
Avg $ ~200
Speed Sensor Module: 34526781575
Avg $ ~75
Thoughts?

Buy the two parts off ebay, install, then have someone remote program?

[deansbimmer]

I think I told you before that your issue is likely stemming from a corrupted CAN line. We diagnose these frequently here. You can diagnose this by measuring voltages at the CAN lines to find the corrupted bus, then de-pinning that CAN line from the module(s) until your communication comes back online. Replace the module that's disconnected when communication is reestablished. Has anyone looked into this on your car yet?

Dealer's only install new parts. A used module isn't going to come with a 100% success rate like a new module would. Also be aware that the DSC assembly is M3 specific. $200 sounds low (wouldn't trust one that cheap)- we usually sell the M3 variety for $500.

[///Monty]

Originally Posted by deansbimmer

I think I told you before that your issue is likely stemming from a corrupted CAN line. We diagnose these frequently here. You can diagnose this by measuring voltages at the CAN lines to find the corrupted bus, then de-pinning that CAN line from the module(s) until your communication comes back online. Replace the module that's disconnected when communication is reestablished. Has anyone looked into this on your car yet?

Dealer's only install new parts. A used module isn't going to come with a 100% success rate like a new module would. Also be aware that the DSC assembly is M3 specific. $200 sounds low (wouldn't trust one that cheap)- we usually sell the M3 variety for $500.

Is there a wiring schematic that you can share with me? I have the tools and knowledge to do these sort of checks, but no drawings. I have tried doing research to find this information for pin readouts, etc, but at best I have found is a flow chart style picture.
Is this the subconnector in the glove box? Supposedly a blue connector with blue wire w/ redstrip pin1 (CAN+) and red wire pin2 (CAN-)??


Those were used modules. Coupled with being on eBay probably accounts for the lower price. The first one I looked at (same PN) was $500.

As for their techs, the service manager told me they did a thorough check of the fuse box, checked voltage on the battery, as well as read error codes. So I highly doubt they did a pin readout of different pins to check for voltage.

I wish I lived near texas so I could bring the car to you!

*edit* -- also, i assume you are talking about K-CAN bus, not PT-CAN?

[deansbimmer]

Bookmark this site:
https://www.newtis.info/tisv2/a/en/e...nctional-info/

It could be either PT-CAN or K-CAN. The last time I saw these symptoms the FRM had failed and brought down the PT-CAN. We also wanted to blame the DSC at first... Check voltage conditions by back-probing the connectors' CAN lines. Then De-pin the suspect CAN bus at the module (I'd try FRM first) and see if communication comes back up with the other modules. If not then try again at the DSC connector.. It's basic CAN troubleshooting. You can google for more details. CAN diagnostics is almost universal.

[///Monty]

Originally Posted by deansbimmer

Bookmark this site:
https://www.newtis.info/tisv2/a/en/e...nctional-info/

It could be either PT-CAN or K-CAN. The last time I saw these symptoms the FRM had failed and brought down the PT-CAN. We also wanted to blame the DSC at first... Check voltage conditions by back-probing the connectors' CAN lines. Then De-pin the suspect CAN bus at the module (I'd try FRM first) and see if communication comes back up with the other modules. If not then try again at the DSC connector.. It's basic CAN troubleshooting. You can google for more details. CAN diagnostics is almost universal.

Awesome! That is a super useful resource. This makes me happy lol. I'll continue to do research and hopefully find the issue. Thanks, Dean!

Hopefully I can figure something out now and won't have to sell my car O.o