All,
I replaced my 5 year old lead acid battery after I load tested it and it was indicating about 75% capacity after a fresh charge. I decided to go with a new Automotive Glass Matrix (AGM). Both are Everstart MAXX batteries.
When I installed the new AGM, after start I get the battery not charging message. If I swap batteries to the old lead acid the message goes away, swap back to the AGM and message appears.
Both batteries start the car fine but the lead acid was getting sluggish in cold weather confirmed by my load test.
New alternator installed this summer probably due to the old battery needing replacement. I'm an electrical/electronics engineer, not a novice.
I'm wondering if there is a setup in IDS/SDD to calibrate the charging circuit for a different battery type?
Anyone else experience that symptom? when upgrading from a lead acid to an AGM?

 

Hi Glenn,

What is the state of charge of the new AGM battery? Perhaps the charge is low from sitting on the shelf and the system is raising the charging voltage accordingly?

As far as I know, there is no option in IDS/SDD for modifying the charge strategy.

I have used absorbed glass mat batteries in lots of Jaguars with no issues, although an AGM is not theoretically the best choice in an X350 due to the elevated charging voltages designed for the original silver calcium batteries. AGM batteries reportedly do not respond well to charging voltages above 14.8 volts, but the X350 charging system can reach 15.3 volts. However, we have many members using AGM batteries in their X350s and no reports of premature battery failure that I can recall.

Cheers,

Don

 

internally regulated

either you have a charging problem or your chinese sweatshop regulator is no good as usual 🤷‍♂️

 

Here's a snip from pdf page 341 of the X350 Workshop Manual Electrical section which clearly states that low battery voltage/state of charge can cause the battery warning light to illuminate:






Cheers,

Don

 

Deep Cycle AGM: AGM batteries should be charged using a charger that has an AGM mode selector. Following
deep cycle usage, use a charger with a current limit of 20% or 0.2C of the battery capacity and a charging voltage
of 14.6–14.8V for deep cycle use, or 13.6V–13.8V for standby use.

 

@RandyS Yes, good advice. My charger/maintainer has a selection for AGM, delivers a maximum of 4.5 amps that is varied by its intelligent charging cycle, actually most of the time it automtically detects the battery type which is quite interesting. I would like to know that technology. Yesterday while charging it went through a series of charging voltages and over the course of several hours went to 14.8VDC for a while,

 

UPDATE: So after some experimenting, and giving the AGM battery a full charge using the 4.5 amp AGM detecting charger/maintainer, the battery seems to keep a constant voltage about 12.85 - 12.87 VDC sitting for a week with no load which is higher than a lead acid battery. Without a doubt, it is definately something in the programming of the Instrument module triggering the message from the higher AGM battery voltage.

On cold mornings I get the "battery not charging" warning message eventhough the alternator is putting out 14.1 - 14.8 VDC at the battery terminals, which the message extinguishes after about 5 minutes or less of driving. Then if I drive the car same day or multiple starts/stops, no message comes up.
Usually I get the message, drive a few hundred feet, stop, switch off the engine and then restart, no message, and still charge voltages at the battery with the message and without.

I have found all sorts of programming niggles in these cars. The one that takes the cake is the OE ECM, that when I upgraded to the last version for a 4.0 AJ27 after intermittent upstream O2 codes and swapping the O2 sensors between my 2000 and 2001 verifying they were indeed working and confirmed by the IDS waveforms, the Bank too lean codes and failed O2 sensors dissapeared and changed to what was actually causing the problem - fuel injector air which got resolved by replacing an O-ring at the throttle body.

Programmers

 

Out of curiosity, what made you "upgrade" your ECM?
Did the "niggles" begin after the upgrade?

 

I've been running AGM batteries in my '01 XJR for more than 10 years. Have never seen that error.

 

The niggles were long before the ECM upgrade and are not isolated to just one of my XJ's, and each x308 car's niggles ended with the ECM update with no other changes.

I upgraded my 2001 X308 AJ27 ECM because it had a number of bad ECM inputs that were causing some very strange CPU internal codes determined by the Dealer shop foreman after pinpoint testing and chasing both banks lean, all upstream and downstream O2 sensors intermittently defective and the host of other pinpoint tests pointing to the ECM. Dealer confirmed my findings, but could not source a replacement ECU. I suspect it was a previous owner or mechanic unplugging/re-plugging the ECM under power chasing bad connectors.

I replaced my first ECM with a latest PN exchange from “Foreign Computer Repair", an automotive repair shop in Texas. That original symptom was from a defective O2 Sensor code that would intermittently throw the codes between all four sensors and then disable the sensors for presets and also restricted intermittent performance messaged. It took the dealer service shop about two weeks to formulate the same diagnosis for a $149 charge. Money very well spent, but I determined a bad ECM before taking it to the dealer, just did not believe my own pinpoint tests.
Updated ECM, same old sensors, same connectors, problems vanished.

The "niggles" on all four of my XJ''s from my 1996 to my 2005 (and by this forum, quite a lot of other owners) were mostly related to intermittent "reduced performance" isolated to a short period after filling my fuel tank which would then disappear after a few miles of driving with no logged codes, then reappear about 1/3 full tank condition again with no logged codes, almost like clockwork. Even the dealer could not diagnose thinking the condition was a vacuum leak somewhere, performing leak tests for himself and myself also in the shop, or some problem with the vapor emissions caused by an altitude issue and the purge valve (I'm at 5000 feet elevation). Purge valves are 1 psi reference calibrated for sea level.

When initially searching for another ECM for my other X308 I thought, I'd again go for the last version designed for my AJ27 to see if that cured my restricted performance, but before searching, I swapped ECMs between my 2000 and 2001. After installing the newer part number and re-performing the security setup, "reduced performance" on my 2000 x308 AJ27 XJ8 immediately vanished, where all four of my XJ's previously had the exact same behavior after filling the fuel tank, two were now cured. So I located a newer PN ECM, installed it swapping back the exchanged ECM and no more restricted performance or missing or erroneous sensor codes. Two x308 XJ's no longer exhibited the problem, The '96 is long gone, and the 05 still needs some intake manifold vacuum leaks fixed first, but the symptoms with the restricted performance is exactly the same, different engine, but early version of the ECM for the AJ33 engine. but note in the DTC's the troubleshooting is exactly the same indicating the programming checks are also, exactly the same.

Another niggle? When the transmission switch starts to fail, causes an intermittent high gearbox temperature fault, but absent a spare input, swaps temps with the engine coolant? HUH!?! 04-09 upgraded the TCM to include more sensor inputs for more gears and communications, along with the instrument Modules

And don't even ask about corroded connectors or sufficient battery voltage, that was another very early tail chasing fiasco from the diagnosis troubleshooting table and advice, neither of those cars had any harness or connector corrosion issues and all had either pin connector TSB updates by the dealer prior to troubleshooting pinpoint tests, which all had gold pins, corrosion free connectors and no broken or shorted wires. I ran those gambits eventually on just about every accessible connector on my X308's over my ownership.

Nothing changed except the version of the ECM. And what is one of the resolutions for the restricted performance? Reflash or update the ECM with a specific campaign level which are always bug fixes.

Now I am not advocating everyone go out and change out their ECM's when their ECM throws a few sensor codes or restricted performance without performing the relevant pinpoint tests at least twice, but when the tests all point to the ECM or the repeated troubleshooting and DTC's do not add up, then it is a strong indicator of the root cause.

Speculate all you want, I have ran that gambit well over a dozen times, the pinpoint tests were all done multiple times by myself, swapping all the recommended sensors and pinpoint tests, flashing with the correct campaign, then again with the dealer service foreman and the same conclusion. The only difference was, the dealer foreman somehow managed to get deeper into the CPU codes in the ECM and gave me a printout of error codes I was not able to drill down into with IDS/SDD. Somewhere there is documentation of what was fixed listed by Firmware and ECM part number hardware upgrades and compatibility of the ECM's across an engine series. Then the 04 models came out. with the AJ33 and the cycle begins again.

Want to see the niggles? Search the forums for undiagnosed restricted performance and see how many had no DTC’s logged in IDS/SDD, and vapor emissions purge valve dealer complaints and related TSB’s, and the exact same problems span 25 years of models right up to this model year, engine types on all JLR models. The only ones that were resolved were DTC vacuum, unmetered leaks or they all threw specific sensor related DTC's pinpointing a bad sensor. Toss those, look for the unresolved ones, those are the niggles.

Then go onto the other JLR forms, same restricted performance issues and similar niggles for the same model range engines.

It is difficult to get detail root failure analysis with limited production volumes across a short model range before the new models come out and when the consumer and dealer are part of the final troubleshooting.

 

I certainly agree that chasing individual connection points is usually not the answer. I also
agree with flashing the ECM to the most applicable level is desirable. It is the "what is
causing the ECM to flash the restricted performance message" when nothing about the
ECM has changed...that makes me wonder.

 

The physical ECM's did change, each to a later part number for both of my X308's AJ27 ECM's, that was the difference.

The company in Texas had told me the ECM update was a design change to add protections to sensor inputs and component changes in the ECM for bug fixes with FW updates which they repair quite a lot of them.
With the first ECM exchange for my 2001, it was plug-n-play as they took the security from my failed ECM and installed it on the new part number. When I installed it, it was literally twist the key and drive. Later when I was curious about the O2 sensors and MAS trends now that I could see them operating, IDS/SDD did indicate there was a newer campaign so I flashed it just to be the latest, not for any issues.

The second ECM, I simply searched for the part number and bought that next one on eBay, did the security commissioning myself using IDS/SDD, ran it for a while and later also updated the campaign FW just for the latest campaign FW.

Actually it was pinpoint tests and individual connection point diagnostics that then said to replace the ECM, which after running through the tests multiple times, I took the car to the dealer who confirmed a defective ECM. So yes, pinpoint tests DO work to get to the root cause if followed properly.

 

"Nothing changed except the version of the ECM. And what is one of the resolutions for the restricted performance? Reflash or update the ECM with a specific campaign level which are always bug fixes."

I guess I misread that posting, or did not quite understand what it meant.