New to me 2017 MX... Code 33 / 007 charging fault...

[Don Thuren]

Just unplugged all 3 connectors from the DCCP at the same time, and Negative isolation KOHMS still low 200's...

 

[Rashid510]

Code 33 on MT, and MT notes very low number 230-260 KOHMS negative isolation..

Weird thing is if the bike sits for a while and I key-on MT will be 260 KOHMS, then cycle the key again 255 KOHMS, cycle again and 250 KOHMS, again 240 KOHMS.... It keeps going lower as I cycle the key over and over....

I unplugged the DCCP harness that connects to the charger, and no change on KOHMS.

The other test would then be to check isolation on the pack. Unfortunately you would need a way to connect to the battery (bypass the DCCP).

 

[Mark911]

Yes, the iso resistance varies as batt voltage/temperature/etc changes over time. Shouldn't change more than 10-15% I would expect. For more safety and redundancy Alta built in circuity into BOTH the positive and negative legs of the HV DC system. If the fault is in the negative side of the leg that's another clue. Since you disconnected the DCCP with NC in isolation I'd lean towards something in or around the battery pack. Could be water in the LV pack connector. If that's not the case and the problem seems to be pointing at the pack there's literally dozens of potential sources for a low negative iso numbers. ANY interaction (and there's many) between the LV and HV circuits inside the pack could be the cause. The HARDWARE biggies are - 300 to 12v DCDC converter and associated circuits, the negative contactor or associated circuits, any one of many opto-isolator circuits, any one of the many data line interface isolators, a few high to low Voltage regulators, the isolation measurement and monitoring components and circuity themselves. Other potential causes - Any water and/or humidity inside the pack, loose conductive debri, damaged cells and/or modules, etc. Also, any corrupt firmware files might do it as well.
Bottom line, other than making sure things are nice and dry the only thing you can do outside the pack is re-load all the firmware (which is always a good idea before digging into the hardware).

 

[Mark911]

Another thought - Rashid gave me a bad HV DCCP cable a few weeks back. The red tag said it failed highpot (a test for isolation). I took the harness apart and actually found a tiny nick in one of the two HV charge wires which was intermittently contacting the pigtail for the shield ground termination wire. You might be seeing something similar. Strange things these electrical/electronic beasts!

 

[datadog]

I replaced one of those DCCP subharnesses in the field after diagnosing it as the problem, solved low negative isolation. I also found a subharness with water intrusion in the connector - it had been removed at some point and was not fully seated when reconnected. It's an easy enough thing to check, and Rashid may know where to find those subharnesses.

 

[Don Thuren]

Sweet thanks guys!

Mark I'll try reloading the firmware that makes sense to at least do that.. I want to say that when I bought this bike the guy told me that the Alta dealer said the charging issue popped up right after doing a firmware update, or something...

Datadog I pulled apart, inspected, and taped up the DCCP harness while in there, and all seemed good. Also, it seems like the bike turns on fine with it completely unplugged to test that as a source of the problem.

 

[datadog]

Sweet thanks guys!

Mark I'll try reloading the firmware that makes sense to at least do that.. I want to say that when I bought this bike the guy told me that the Alta dealer said the charging issue popped up right after doing a firmware update, or something...

Datadog I pulled apart, inspected, and taped up the DCCP harness while in there, and all seemed good. Also, it seems like the bike turns on fine with it completely unplugged to test that as a source of the problem.

Sounds like your problem is not in the subharness.

 

[Don Thuren]

Mark's been helping me a bit(thanks Mark!), and I tried replacing this switching mosfet thingy, but still no luck. Kinda fun doing this stuff though. Used a 5min setup thermal epoxy and added a little heatsink anyways!