battery removal - what gets cleared?
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From: Douglasville Ga.
I hope nothing. I have had my XK8 battery disconnected for several days at a time while repairing ABS modules and didn't have any problems. I just didn't use sport mode for a couple of drive cycles.
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From: Tasmania, Australia
Not sure if your spec has radio code or not.
Oz spec cars (ROW) has radio code.
Disconnecting battery doesn't seem to affect ECU memeories.
Just run the car through a full drive cycle....including using the 'J-gate' and Sport mode switch....vary speed up and down.
This basically resets or re-learns the ECu and gearbox ECM.
Some experience a brief 'high idle' period but this goes away after a drive cycle.
I use an automatic 6 stage charger which can be set on de-sulphation mode which takes 24 hrs before resumes bulk charge and float.
Has helped my 11 year old Varta Silver Calcium sealed battery go the distance and still behaves like a new battery.
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From: Sunny Southport UK
Throttle calibration resets (initial startup and variable revs as throttle recalibrates)
Trans - follow the adaptation process for best performance
ECU nothing
Memory (seat steering position) - sometimes!
Radio presets or code
climate - last setting
That's all I can think of right now...
Trans - follow the adaptation process for best performance
ECU nothing
Memory (seat steering position) - sometimes!
Radio presets or code
climate - last setting
That's all I can think of right now...
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From: Limousin, France
For an XK8/R but I'd guess the same (you get an honourable mention too)
https://www.jaguarforums.com/forum/x...connect-74146/
https://www.jaguarforums.com/forum/x...connect-74146/
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From: on-the-edge
Thanks guys.
No radio code, so no problem.
I was really only concerned about seat memory, mirror memory and fob association with the memory. Very fiddly and time consuming to get right. Guess I'll just hit the memory save button before moving anything.
... arghh! Just did the full transmission adaptation cycle by the book last month. Had to find a disused country road at 2:00am to have enough room ... in another town.
It didn't change the shifting behaviour anyways. So, not that fussed by it. I habitually use 4+S except on the highway.
BTW ... an interesting tidbit from JTIS ... when reconnecting the battery ... a minimum of 30 seconds must have passed since the last disconnect. Guess this is to avoid partial reboots of systems.
The genesis of all this is a suspicion that the regulated alternator voltage is too low for proper charging of lead/calcium type batteries such as the Delco Freedom Maintenance Free types. They *like* 14.8vdc. Short trips result in a chronic charge deficit due to inadequate charging.
And there is a ground circuit that almost never gets mentioned in troubleshooting threads. The attachment of the alternator case to the engine. Any corrosion here results in lower voltage and poorer charging because the regulator signal floats above ground potential. On a 12 year old car with an undisturbed alternator ... it's a worthwhile place to investigate.
No radio code, so no problem.
I was really only concerned about seat memory, mirror memory and fob association with the memory. Very fiddly and time consuming to get right. Guess I'll just hit the memory save button before moving anything.
... arghh! Just did the full transmission adaptation cycle by the book last month. Had to find a disused country road at 2:00am to have enough room ... in another town.
It didn't change the shifting behaviour anyways. So, not that fussed by it. I habitually use 4+S except on the highway.
BTW ... an interesting tidbit from JTIS ... when reconnecting the battery ... a minimum of 30 seconds must have passed since the last disconnect. Guess this is to avoid partial reboots of systems.
The genesis of all this is a suspicion that the regulated alternator voltage is too low for proper charging of lead/calcium type batteries such as the Delco Freedom Maintenance Free types. They *like* 14.8vdc. Short trips result in a chronic charge deficit due to inadequate charging.
And there is a ground circuit that almost never gets mentioned in troubleshooting threads. The attachment of the alternator case to the engine. Any corrosion here results in lower voltage and poorer charging because the regulator signal floats above ground potential. On a 12 year old car with an undisturbed alternator ... it's a worthwhile place to investigate.
Last edited by plums; Jun 4, 2013 at 10:56 PM.
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From: on-the-edge
mission accomplished
The battery went from 12.36vdc open circuit which is about 55 percent state of charge for a lead/calcium plate battery to full charge with float voltage of 13.09vdc.
But ... more importantly, it allowed a baseline to be established for making future measurements quickly without having to go open circuit as is usually required
After starting and going off fast idle, the charging circuit sat at 14.2vdc at the battery posts. 14.8vdc would be better for short trips.
The battery baselines at 12.93vdc after turning off the engine, key out, and trunk open for 5 minutes to both drain the float charge and allow for the usual time to open the trunk and expose the battery for measurement without having to go open circuit.
But ... more importantly, it allowed a baseline to be established for making future measurements quickly without having to go open circuit as is usually required
After starting and going off fast idle, the charging circuit sat at 14.2vdc at the battery posts. 14.8vdc would be better for short trips.
The battery baselines at 12.93vdc after turning off the engine, key out, and trunk open for 5 minutes to both drain the float charge and allow for the usual time to open the trunk and expose the battery for measurement without having to go open circuit.
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From: Limousin, France
It's worrying about your lead/calcium charge voltage. This type of battery seems to be getting much more common.
I don't know how the ECM senses battery voltage -I think the ECM controls the regulator rather than an integral doodad in the alternator.
A wee voltage divider in the sense line (or a diode for the 0.6v drop) might do the trick ?
I don't know how the ECM senses battery voltage -I think the ECM controls the regulator rather than an integral doodad in the alternator.
A wee voltage divider in the sense line (or a diode for the 0.6v drop) might do the trick ?
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It's worrying about your lead/calcium charge voltage. This type of battery seems to be getting much more common.
I don't know how the ECM senses battery voltage -I think the ECM controls the regulator rather than an integral doodad in the alternator.
A wee voltage divider in the sense line (or a diode for the 0.6v drop) might do the trick ?
I don't know how the ECM senses battery voltage -I think the ECM controls the regulator rather than an integral doodad in the alternator.
A wee voltage divider in the sense line (or a diode for the 0.6v drop) might do the trick ?
The diode would do the trick. The difficulty with Jaguar is that they chose not to use the remote sense line provided by the Denso regulator. That should have been routed to a junction close to the battery. That leaves the other two lines to guess at.
Denso also usually ships regulators with a 14.5v set point which would have been preferable. Don't suppose in your multitude of catalogs and sources you could determine the pinouts of the existing or similar regulator? It's the newer three pins in a line version.
I am guessing that many of the low battery problems for these years can be laid at the doorstep of the choices made by Jaguar. The problems in the newer models seem to be even worse. This would be caused by the newer charging algorithms that are designed to ... you guessed it ... improve reported CAFE and related fuel economy mandates. They shaved it too close, and the battery problems in the newer models are biting owners.
The latest generation premium lead/calcium batteries have never been better. The problem lays in the new generation charging systems.
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From: on-the-edge
and to make things worse ...
From an article at autospeed.com:
ouch ... that was a Cobra kit car. Not nearly as much electronic gizmos as found on a late model Jaguar.
The draw at idle was 14 amps, comprising the load of the fuel pump, injectors, computer, instruments, etc. Turning the headlights on saw another 15 amps being drawn. I then switched on the cooling fan and saw a total draw of 59 amps at 800 rpm idle.
If I put my foot on the brakes, the alternator wouldn’t cope and so the system started drawing current from the battery.
If I put my foot on the brakes, the alternator wouldn’t cope and so the system started drawing current from the battery.
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From: on-the-edge
Notice the list above did not include the usual mod-cons such as air, stereo, heated screen, power window usage and such. Items that are usually desirable when sitting in traffic, which is when 800 rpm conditions exist. In running around the globe electronically, the figure most often quoted as the parasitic power consumption is 5HP.
Already spent hours at it.
It is D-IG-L. Meaning "dummy", "ignition", "lamp". So, there is no "sense" wire to use or fiddle with.
JTIS says this:
Now, if Translator would just drop by and parse that properly, it would appear that "IG" is only a supply and no amount of external deception is going to affect the programmed field voltage. Floating the ground would work, but it has to be done as a modification internally. At that point, might as well install another regulator. Certain Land Rovers have the same regulator type with a 15V set point. But, no one can find them for love nor money.
There is of course the option of a regulator for a Camry which has the same basic design and fitment, but it has a "S" terminal which is not entirely a bad thing. Because the "S" terminal can be manipulated as desired.
BTW, the cause of all the angst with pictures not showing properly may be in the picture upload function. It discriminates against .gif files and resizes them much more aggressively than .jpg, .png, .bmp, etc. The diagram was a .gif of about 42kb. Perfectly fine for blank and white. But noooo, the server resized it to a minuscule thumbnail. Redoing it as a .jpg showed it properly ... but, at a cost of 220kb. Not good for farmers running modems on barbed wire
Already spent hours at it.
It is D-IG-L. Meaning "dummy", "ignition", "lamp". So, there is no "sense" wire to use or fiddle with.
JTIS says this:
The voltage regulator senses (at the 'B' terminal) battery terminal voltage, which within limits is proportional to the state of charge of the battery. The regulator then adjusts the supplied voltage between the 'IG' terminal and the regulator 'F' terminal (a continuously variable process) to maintain the 'B+' output at a constant level.
There is of course the option of a regulator for a Camry which has the same basic design and fitment, but it has a "S" terminal which is not entirely a bad thing. Because the "S" terminal can be manipulated as desired.
BTW, the cause of all the angst with pictures not showing properly may be in the picture upload function. It discriminates against .gif files and resizes them much more aggressively than .jpg, .png, .bmp, etc. The diagram was a .gif of about 42kb. Perfectly fine for blank and white. But noooo, the server resized it to a minuscule thumbnail. Redoing it as a .jpg showed it properly ... but, at a cost of 220kb. Not good for farmers running modems on barbed wire
Last edited by plums; Jun 6, 2013 at 03:58 AM.
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There are any number of choices including ... get this ... a regulator for Caterpillar, Isuzu, Komatsu, etc. All exact physical and electrical fit.
Any clues in the circuit diagram?
Any clues in the circuit diagram?
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Just a brilliant rant on complexity in vehicles:
As soon as processor-reliant components are introduced into any system, two more potentially troublesome elements are introduced: microcircuit hardware and coded software. Unlike a four- or five-terminal relay, which can be trouble-shot by a trained gibbon, computers need diagnostic experts with high levels of skill and training.
You are also at the mercy of potentially inept programming which creates logic errors ('bugs' to you and me). On a CANBUS-controlled vehicle, this could cause erratic operation if battery voltage isn't up to spec, component malfunctions, sensitivity to changing resistance... nudge, nudge, wink, wink...
At my last technical authoring stint, I worked at BAE Systems. I was told a fascinating story about the SA Air Force's newly-introduced SAAB Gripens. The plane was introduced with enormous fanfare to the SAAF brass as 'The best air-superiority fighter in the world'.
On the day the plane was to be publicly introduced at Waterkloof AFB, nearly all the delivered fighters' engines started - and promptly died! This caused the much-anticipated aerial demonstration to be scrubbed, amid great embarrassment on the part of SAAB.
The explanation came through a couple of weeks later. The Gripen's Volvo-aero turbofan originally used control software that had been set up for Swedish local conditions (ambient temperatures of 15 degrees C maximum at the height of the Swedish summer). At the height of our summer, ambient air temp is more like 30 degrees. Under start-up conditions, the plane's environment-monitor ECU interpreted the high ambient temp as a sign that the engine was overheating, and since the plane was still on the ground, promptly cut off the fuel supply.
Control software can be a bit like 'flu... invisible and intangible as it is, it can still make your life an utter misery if it's virulent enough...
As soon as processor-reliant components are introduced into any system, two more potentially troublesome elements are introduced: microcircuit hardware and coded software. Unlike a four- or five-terminal relay, which can be trouble-shot by a trained gibbon, computers need diagnostic experts with high levels of skill and training.
You are also at the mercy of potentially inept programming which creates logic errors ('bugs' to you and me). On a CANBUS-controlled vehicle, this could cause erratic operation if battery voltage isn't up to spec, component malfunctions, sensitivity to changing resistance... nudge, nudge, wink, wink...
At my last technical authoring stint, I worked at BAE Systems. I was told a fascinating story about the SA Air Force's newly-introduced SAAB Gripens. The plane was introduced with enormous fanfare to the SAAF brass as 'The best air-superiority fighter in the world'.
On the day the plane was to be publicly introduced at Waterkloof AFB, nearly all the delivered fighters' engines started - and promptly died! This caused the much-anticipated aerial demonstration to be scrubbed, amid great embarrassment on the part of SAAB.
The explanation came through a couple of weeks later. The Gripen's Volvo-aero turbofan originally used control software that had been set up for Swedish local conditions (ambient temperatures of 15 degrees C maximum at the height of the Swedish summer). At the height of our summer, ambient air temp is more like 30 degrees. Under start-up conditions, the plane's environment-monitor ECU interpreted the high ambient temp as a sign that the engine was overheating, and since the plane was still on the ground, promptly cut off the fuel supply.
Control software can be a bit like 'flu... invisible and intangible as it is, it can still make your life an utter misery if it's virulent enough...
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From: Limousin, France
If you follow terminal 3 (B+) back leftwards there's a connection into the voltage regulator (white circle). That's the volts sense input - if you cut that and put your diode in (anode to B+) it will up your charge volts by 0.6v
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argh .. no joy.
What's the effect of the two vertical circuit fragments to the left of the chip?
One with only a condenser, the other with a transistor and diode. Filter and bypass?
What's the effect of the two vertical circuit fragments to the left of the chip?
One with only a condenser, the other with a transistor and diode. Filter and bypass?
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From: Limousin, France
Filter and I'd guess the diode is actually a Zener which gives the reference voltage.
A bit wierd but a variant on this
http://pubpages.unh.edu/~aperkins/pd...nijunction.pdf
By 'no joy' you mean it didn't work?
Can you get to the junction of the diode and transistor collector to see what volts it sits at?
A bit wierd but a variant on this
http://pubpages.unh.edu/~aperkins/pd...nijunction.pdf
By 'no joy' you mean it didn't work?
Can you get to the junction of the diode and transistor collector to see what volts it sits at?
Last edited by steveinfrance; Jun 6, 2013 at 05:42 AM.
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"Oh, I see" said the blind man to the guy driving with a necker's knob. 
No ... no joy means I'm unhappy at the prospect of it not being possible to add the diode at the exposed IG or L inputs. It's been done internally by someone who floated the ground on the regulator through a diode. You snip the strap on the regulator running to ground and insert the diode there. Of course, after going to the trouble of opening the case, one might as well install new brushes and a suitable regulator that does not need surgery.
There is one small straw left to grasp. The setpoint on the regulator is *supposed* to be 14.5v but I am seeing 14.2 at idle. So readings need to be taken at off idle as well. to see if 14.5 ever gets achieved. The 0.3 differential may lie in the fact that the B+ cable connection has been there for 11+ years and the same for the machined face contact at the mounting lug.
All of the other main junctions have been cleaned, tightened and greased. Time to order new idler and tensioner bearings as well as plan an oil change at the same time.
Hmmm ... I wonder if it would be okay ... as in it wouldn't hurt ... to try the diode at the IG position.
No ... no joy means I'm unhappy at the prospect of it not being possible to add the diode at the exposed IG or L inputs. It's been done internally by someone who floated the ground on the regulator through a diode. You snip the strap on the regulator running to ground and insert the diode there. Of course, after going to the trouble of opening the case, one might as well install new brushes and a suitable regulator that does not need surgery.
There is one small straw left to grasp. The setpoint on the regulator is *supposed* to be 14.5v but I am seeing 14.2 at idle. So readings need to be taken at off idle as well. to see if 14.5 ever gets achieved. The 0.3 differential may lie in the fact that the B+ cable connection has been there for 11+ years and the same for the machined face contact at the mounting lug.
All of the other main junctions have been cleaned, tightened and greased. Time to order new idler and tensioner bearings as well as plan an oil change at the same time.
Hmmm ... I wonder if it would be okay ... as in it wouldn't hurt ... to try the diode at the IG position.