Wrangler battery goes dead. Instrument cluster LIN bus never shuts down
Longshot here. I am not experienced at all with domestic cars, but I was asked to look at this jeep that kills batteries. The customer narrowed it down to fuse M13 which supplies the WIN/WCM, cluster, and multifunction switch (turn signal switch). Not equipped with alarm module or ultrasonic sensors on this car (if equipped would be supplied from M13).
There are a few scenarios that may happen:
- After 3 - 5 minutes, vehicle goes to sleep and draw is acceptable, around 20-35 mA.
- After 10 minutes, draw indefinitely stays around 800 mA, with a draw on fuses M10, M11, M12, M13.
- After 5-15 minutes, draw indefinitely stays at 500 mA, with a draw only on fuse M13
I am focusing on scenario 3, because that is the most reproducible of scenarios 2 and 3.
I traced 480 mA of that going to the instrument cluster. Scoping of the cluster data lines shows that CAN will go idle shortly after key off, but the LIN bus will communicate indefinitely.
I have physically unplugged all items present on the LIN bus, the left multifunction switch, offroad switch bank, seat heater module, and the lower switch bank. I can't access the compass module, but I did remove fuse M34 which supplies it. Still, LIN bus activity continues, as well as the 500 mA draw. Unplugging the cluster causes activity to stop, as well as the draw.
I've tried to decode the LIN messages on my autel scope, but either I'm not getting the baud rate correct, some other setting is wrong, or it just doesnt work on the software.
It would seem the cluster is bad, but I don't know if the cluster is perhaps sending shutdown messages on the LIN, and waiting for confirmation messages before shutting itself down.
The only relevant code that was recorded was stored in the cluster for seat heater module missing message, however the seat heaters work, and I could not get this code to set again.
Anyone have intimate product knowledge of these jeeps, or can say if I am on the right track with a bad cluster, or know of any common issues with an M10-M13 fuse draw?
There is a lot of forum posts about M13 draws, but really no evidence or solutions I saw. Most say it is an ongoing problem. A few said the dealer replaced their TIPM, but these are constant supply B+ fuses, and the CAN bus is idle while the draw is present, so I don't believe the TIPM could be causing this.
Not 100% sure,but i did replace a few clusters on 2013 and 2015 for same issue..
It may be worth de pinning the the power, ground, or LIN at the cluster connector, and hooking everything back up to possibly further narrow down the cluster is the issue and not another module on the network causing an issue. Just food for thought.