Expert Level - Charging System Fault 2016 LR4

[97disco]

What do you do when you already have a couple rovers? Buy another one of course!

I picked up a 2016 LR4 with 77,000 Miles with a rebuilt title from a trade in. Showed a "Charging System Fault" and I didn't think much of it as it's typically just an alternator, battery or something straight forward. Drove it home and found all the service records (over $8,800 in three years) from the previous owner who had chased in problem for over a year and gave up.

Battery shows 12.7V
When running 13.6V

SERVICE RELATED HISTORY (per shop receipts):
Previous owner bought it in 2022 as a rebuilt with 42k.
AUG of 2023: 64K MILES, He replaced the alternator by an independent shop.

AUG 2024: Independent shop service to diagnose the "Charging System Fault", proceeded with the following:

1. Direct Comment from Technician: "Vehicle is requesting 14.2v vehicle is charging at 13.6. Tested signal wire from BMS module (battery monitoring system module) back to Gateway Module. Confirmed integrity and can hold a load. Updated software on gateway module. No change. Inspected and found vehicle data shows incorrect battery installed. Inspected and found lead acid battery installed. Called dealer and confirmed agm battery should be in place. Recommend before any further testing that new agm battery be installed then continue diag if no change."
2. Shop replaced with new NAPA AGM battery. Direct Comment from Technician: "Installed new battery, and the system is still showing a charging fault indicator. I tested the LIN (local interconnect network) communication wire from the alternator and the PCM. I checked for continuity between the the pom and the alternator on the LIN circuit. I have good resistance there. I load tested the circuit. All checks out there as well. Then tested circuit for a short to ground. Checks okay there."
3. Installed New Alternator from JLR ($1,200), however, it appears to be a re-manufactered. Direct comment from Technitian: "Per Land Rover/ jaguar specs, installed new alternator, installed new battery, tested all circuits for opens, high resistance, short to ground, and load tested circuit. Based off testing results and Land Rover specs, Land Rover says to replace PCM (powertrain control module )"
4. Shop could not resolve, suggested replacing the PCM.

SEPT 2024 Owner took the vehicle to the local JLR Dealer:

1. Technician comment: "Verified the customers complaint, but also noticed that the eco light comes on right before or at the same time as the charging system fault message. Checked fault codes and the GWM has had faults set for the secondary battery and the generator control module (B13C5-92, POA1A-87) Checked the charging system at the main 12v battery and measured 13.6v, checked the aux 12v battery and measured 9.3v. Found that the power distribution box has failed and has caused the aux 12v battery to fail and is causing the charging system fault message to come on due to not charging the aux 12v battery properly. Est power distribution box and aux 12v battery"
2. Replaced the secondary Start/Stop battery. (Not confirmed if through dealer or not)
3. Replaced the Power Distribution Box. (Not confirmed if through dealer or not)

ALL THIS DID NOT RESOLVE THE "CHARGING SYSTEM FAULT".


CURRENT TESTING AND DIAGNOSTICS:

1. Battery currently tests at 12.7 V. (manufacture Date of 05/2024) Passed test from Nampa. I did have to put it on a charger to get it back to 100% and re-installed. Only added a few more seconds to the warning message upon start-up.
2. When running, the charging system is at 13.6 V and does not increase.
3. I have tested under maximum load by running all electronics I could think of (AC, heated seats, heated windshields, stereo, headlights, etc) and the charging system does not go above 13.6V.
4. Grounds show no significant voltage drops. No visible corrosion, and no corrosion at the right-wheel arch.
5. Tested the positive wire for the BMS back to the BMS sensor. minimal resistance
6. Tested positive to the alternator.
7. Checked the "Power distribution box" near the secondary start/stop battery. When running, 13.6 V to all three points. When turned off, 13.2 V from the secondary battery, 12.7V to the other points (from main battery, to fuse box).
8. Removed alternator and had it tested at Autozone. Passed test with around 14.33 under load.

There has also been an oil leak from the Vacuum Pump near the alternator for some time. I had to replace the alternator on my 2019 Discovery (around 60k) because of the oil leak which also showed a "Charging System Fault" message. I assume the oil leak had ruined the FIRST Alternator the previous owner installed in AUG 2023.

Question: I did not test the LIN Communication wire to the back of the battery. But any other way to test without an oscilloscope or GAP tool?

Any suggestions? I feel like the JLR Dealer didn't do a good job and diagnosing, but did find "a problem" and assumed it was the cause.

Thanks in advance!

 

[itsaguything]

Thank you for the detailed summary. I had not seen this in the other forum.
Truly, I can't see the poor quality Napa battery being the issue.
And you've ruled out the generator as it is a reman and load tested it worked out.

You mention grounds are good. And all cables and connections? Some have had their power distribution boxes replaced, which fixed similar issues.

Undoubtedly, the dealer followed the pinpoint tests. But it seems the vehicle was back and forth between a dealer and not a dealer. And that's where it falls apart.

Moreover, you mention "retitled" which has me wondering... retitled from what event? As you mention, something as simple as a minor voltage drop causes havoc. I think you're on the right path. Do you have the Workshop Manual?

 

[powershift]

POS alternator. Mine charges way tf more then that at 14.5V or so. Read up on AGM battery charging. There may be times when it is at 13.6V, nothing wrong but staying at that voltage is a charging problem.

 

[greiswig]

I wonder if most parts stores’ testers can properly test a PWM alternator output?

 

[97disco]

Here's a pic of the test results:

 

[97disco]

Removed the alternator from the '19 D5, installed the one from the D4... no fault codes on the D5.

However, I noticed the alternator LIN wire was replaced with an aftermarket pigtail at some point. (see pics). Looks like they modified the connector to make it fit.

I ordered a replacement.

 

[97disco]

Thank you for the detailed summary. I had not seen this in the other forum.
Truly, I can't see the poor quality Napa battery being the issue.
And you've ruled out the generator as it is a reman and load tested it worked out.

You mention grounds are good. And all cables and connections? Some have had their power distribution boxes replaced, which fixed similar issues.

Undoubtedly, the dealer followed the pinpoint tests. But it seems the vehicle was back and forth between a dealer and not a dealer. And that's where it falls apart.

Moreover, you mention "retitled" which has me wondering... retitled from what event? As you mention, something as simple as a minor voltage drop causes havoc. I think you're on the right path. Do you have the Workshop Manual?

So the owner bought it in NOV 2022 with 42K miles as a branded/rebuilt title (I have the paperwork)... and get this.... for 29K!!!

I feel bad as he got completely ripped off on a 6 year old branded LR4 for that price is insane.

He drove it for 20K when he replaced the alternator from an independent shop in AUG 2023. This alternator must have failed as it was replaced by ANOTHER independent shop in AUG 2024 with 64K miles on the clock.

I do not have the workshop manual. Do you have a link for the 3.0 SDV6?

 

[itsaguything]

PM me.

 

[itsaguything]

Well... the previous owner replaced the POS generator... with another POS generator. What's the definition of insanity?

Merry Christmas!

 

[powershift]

Putting a volt meter on the battery with the engine running shows the alternator is putting out 14.9V and not 14.5V like I mentioned earlier in the thread. Then after shutting down and disconnecting the battery cable it sits at 13V. 12.9V+ is charged.