Expert Level - Charging System Fault 2016 LR4

[itsaguything]

Variable output from the generator based on load and current state. And residual charging voltage on the battery is probably what you're reading... What's the battery reading after sitting all night?

 

[powershift]

That reading is after one startup after a 60A charger was left on the battery for 7 hours with the negative cable disconnected. I was wanting to point out the 14.33V in the OPs test result is not enough. With the battery left disconnected overnight it will still read 13V. After a few days it will drop to 12.9xV while disconnected.

 

[djkaosone]

OMG!! I've chased my fair share of voltage issues over years. I've gone through 3 alternators, 6 batteries, and simply accepted my fate. My voltage will typically range from 12.xV to 14.xV, but rarely stays at 14.xV. Most of the time it's 12.xV to 13.xV. Long story short, ALL my electrical gremlins went away and now constantly getting 14.xV with a $7 Littlefuse 400A Mega Fuse, just last year. For $7, it's worth a shot.

 

[97disco]

OMG!! I've chased my fair share of voltage issues over years. I've gone through 3 alternators, 6 batteries, and simply accepted my fate. My voltage will typically range from 12.xV to 14.xV, but rarely stays at 14.xV. Most of the time it's 12.xV to 13.xV. Long story short, ALL my electrical gremlins went away and now constantly getting 14.xV with a $7 Littlefuse 400A Mega Fuse, just last year. For $7, it's worth a shot.

Thanks I'll definitely give that a shot. Where is the location of that fuse?

I ordered a replacement Alternator plug on eBay but it's not a good fit and doesn't securely clip into place.

Sigh.

SO unfortunately I have not been able to rule that out.

 

[djkaosone]

Thanks I'll definitely give that a shot. Where is the location of that fuse?

It's located on the positive (+) cable on the battery post.

 

[97disco]

It's located on the positive (+) cable on the battery post.

View attachment 26852

replaced an unfortunately no change.

 

[Lr4KP]

I recently had the same issue. Replaced the alternator and light stayed on. It was my negative battery terminal. There is a module on the top of it that went bad. I replaced it with a used one and no codes now

 

[Lr4KP]

 

[powershift]

I'm curious about that part. There is a bare wire hanging off it and its connector with BMS written on it somewhere and I'm constantly handling it to disconnect the battery so I thought if I ever break it while handling it then I'll know what I need to buy lol. What is the specific Land Rover part number or part name for it?

 

[97disco]

PDATE:

Still no fix. GAP TOOL had the following codes:

Vehicle scanned on 06-02-2026 12:01
Using IIDTool BT V4.0 B0098

BCM-Body Control

• U0241-00 (2E) Lost communication with the headlamp control module A
  ( on 06-02-2026 11:53:52 at 78845 mi )

GWM-Gateway module

• P0A1A-87 (2F) Generator control module - Bus signal/message failure - missing a message
  ( on 27-01-2026 20:44:55 at 78845 mi )

HVAC-Ventilation

• B13C2-86 (2F) Windshield misting sensor - Bus signal/message failure - signal is invalid
  ( on 27-01-2026 20:44:55 at 78845 mi )
• B13C2-96 (2F) Windshield misting sensor - Component failure - internal failure
  ( on 27-01-2026 20:44:55 at 78845 mi )

RCM-Airbag

• B1212-13 (AB) Driver safety belt buckle pretensioner deployment control - General electrical failure - circuit open
  ( on 27-01-2026 20:45:08 at 78845 mi )

I also located a pinched wire from the harness to the alternator, did a temporary twist and after 30-sec from startup the charging system fault returned.

I then ran a temporary wire directly to the alternator to bypass the previous repair. Again, after 30-sec from start the charging system fault returned.


Any ideas based on the fault code P0A1A-87 (2F) ?