I may have found a partial answer. A bad parking brake module (the electronic brain) can cause both messages, just like a battery problem can also do:

https://www.jaguarforums.com/forum/1829748-post35/

Not the answer I had hoped for, but oh well.

Still no idea if you only get one message with a bad parking brake actuator, the motor that actually applies the parking brake.

 

On Saturday, I probed every fuse in both fuse boxes, and the total draw is right around 50mA, so nothing unusual. After that, I put the battery on the charger for 36 hours. The CTEK was in float mode when I got to it this morning, so it appears to have passed the Analysis check. Voltage before engine start: 12.8V
Charging Voltage: 14.5v
OBDII Voltage: 13.6v (it must be regulated, it would make sense) [edit: turns out 13.6v is the average of 14.4 and 12.8]

When I got to work and parked, I bypassed the parkbrake (paddle down while pulling the key), then checked the battery voltage. 12.3v

Time to take it to someone and have the battery tested. I can't monitor the charging voltage or log it, because the OBD power is regulated, and I don't have a PID for Charge Voltage. I could bodge together a datalogger (Arduino!), but I think it's just time to take it to a parts store and have them test the battery. If it's fine, then there must be a charging problem, no?

Ken

 

Ken, how are you taking those voltage readings? Reading between the lines, is that with an OBD scanner? Or are you measuring with a separate meter right at the battery terminals? I'd suggest the latter just to be sure of accuracy.

You mentioned 14.5v as the charging voltage. That's from the alternator, not the battery charger, right? I think so, but want to be positive. Does the alternator's charging voltage ever settle down to approximately 13.5v? I think that's the normal pattern you want to see after a few minutes run time with a late model car. On my '02, I don't see it above 13.5v, but I'm not sure if that was how the early models were designed, or if the battery already has a good state of charge (long round trip as a daily driver) so the 14.5v initial burst is never commanded. Anyways, since you did mention 14.5v, if that never drops down, your battery may be getting cooked.

Lazy as I am, I'd suggest making sure the charging system is within specs before having the battery tested. The 12.3v you recorded right after shutdown seems a bit on the low side.

I'll mention again the good results I've had with a meter that plugs into the cigarette lighter. The charging voltage isn't really monitored while driving, and you can't trust the little battery warning light on the dash. It annunciates some failures, but sadly if the alternator's control module totally died, you'd get no warning light. That's why I previously suggested something like this:



With this particular model, the blue digits are hard to read in direct sunlight, so maybe shop around for similar products. Even if you hate the thought of such an accessory, it's still a good idea for the interim until you get this sorted out. It even has a little buzzer to catch your attention if voltage drops low, so you don't have to constantly monitor it.

 

Um, Ken, here's another red flag. Per the quiescent drain write-up, linked earlier in post #6, the limit is 30mA, not 50. Also there are 3 fuse boxes, not 2. That means you may have missed some circuits, so the total drain may be higher. The overlooked fuse box is probably the one on the outboard side of the passenger (US) footwell.

A quiescent drain may not be the root cause, though, so maybe keep this on the back burner. I'm more concerned with the valet incident, and the 12.3v recorded separately right after shutdown. That has me suspicious that your charging system is not operating at full capacity.

 

I'm going to to voltage drop tests tonight on the charging system. It's a little bit of a pain to have the battery in the trunk when doing this, but I'll manage.

And, thanks for the point about allowable quiescent drain. I remembered 60mA for some reason, not sure why. Since it's so easy to check voltage drop on these fuses, I'll quickly check the panel anyway. Wouldn't be the first time my car was suffering multiple failure modes simultaneously.

Insert some outdated joke about Lucas electronics.

Ken

 

I'm taking voltage readings, when possible, directly at the battery with a multimeter. Charging voltage, until I drive off, was measured the same way. The 13.6v number is coming from my OBD scanner.

That 14.5v number was taken right after I started it up, after removing the battery charger. I didn't wait for it to settle down before driving off (running late for work). I will take another reading tonight, after I get home, but before shutting off the car to see what the charging voltage is at the battery. However, it may be that, by the time I got Torque configured to start logging the voltage, it had settled down and was reading 13.5-13.6v. The trace never deviated from that range, so that might be the charging voltage. I'll find out tonight.

I've got something like that already - just need to find it. I also have a test adapter for my multimeter that will probably work as well.

Thanks for staying engaged and plugged-in to my odyssey

Ken

 

Went to AutoZone on the way home and had them test the battery and charging system. I don't know how authoritative their equipment is, but he said everything was "perfect".

When I left work, the battery read 12.5v, up from 12.3v when I parked. I started the car and took note of the voltage at the battery: 14.4v. When I checked the OBD voltage, it said 13.4v. It seems to read almost exactly 1 volt too low. When I got to AutoZone, it was still show 13.1v, and the direct battery reading was 14.1v. After I got home, I let the car idle in the driveway until I noticed the OBD voltage drop down to 12.8v. Got out and took a direct battery reading and it was 13.8v. So, the charging system will *eventually* settle down to a lower voltage.

I then went through and did a better quiescent drain test. Hooked up my meter between battery neg and body, then buttoned her up and locked it. It read 4A until a few seconds after it was locked and all the lights went out, then it dropped to 750mA. After an hour, it had dropped to 60mA. Too high.

I was planning on doing a voltage drop test tonight, but I'm too tired. I won't be able to even attempt it until Wednesday evening.

Probably unrelated, but maybe important because it's electrical, and has the potential to create a large current short: I was getting a misfire today, but only under moderately hard accel. I romped it a few times up hills and got it to trip a misfire code. Cylinder 3. Checking my Bank 1 O2 sensor voltage and fuel trim traces (I run the data logger in Torque to check fueling every time I drive it, since I had a crank-no-start problem last year), and Bank 1 has been running slightly rich for a while now. Failing coil. Potential short? I already had a new coil on the way because I could feel it hesitating at high RPM under load. (What good is driving a rocketship if you can't have fun with it now and then?)

Car is on the CTEK again tonight. I need to find a parking space close enough to an outlet to charge the battery while at work. I need to figure this out because, come first of Feb, I'm moving to a different parking garage with employee-only valet parking (HELL YES), and don't need them fighting the EPB :/

Ken

 

So, if the battery checks out fine, and the charging system checks out fine, then would a cheap next step be to disconnect the battery cables, clean them thoroughly, then reattach them? I already know that I had a bad body ground right at the battery last year. I was getting horrible flickering of the lights - all the lights. After reading around the forums, I decided to pull the ground bolt and chase the threads/clean them up with a tap and die. After reattachment, the flickering was gone. So... maybe pulling the cables and doing a little OCD cleanup and reattach might be in order.

Ken

 

Cars post-2002.5MY have a smart charging system - thus the 14.5V (even 15.1V) for a while. It won't do it every time as it figures it out. Then it drops to a lower figure. See JTIS - they wrote it down so you can read it.

It's also why you need to fit the right kind of battery i.e. good old lead acid. It's not optimised for some of the new-fangled stuff.

I am fairly sure the dash (ETM) and OBD volts are after some lengths of wiring or some voltage regulators or the like as mine also reads lower than using a meter (any of them as I have a few). So, don't panic over that.

However, that does not rule out a bad power/ground connection. You can attempt to do that by using the same meter to check volts around the car. You need the car to be drawing a decent current (to exaggerate the effects of any bad connection) or it'll be fooled. Put headlights on, seat heaters if you have 'em, and so on. I think it should be OK to run the engine (don't want to flatten the battery) but haven't thought that through. (Feels OK, since any drop probably doesn't care if battery is sourcing or sinking current.)

 

The general consensus seems to be 12.6v minimum before starting. Is it worth gambling on a new battery, since your charging system seems to be fine? Tough call, but I'd probably try it before digging into anything else more expensive.

Has the car behaved itself in the morning after the times you had the battery on the charger? That should give a big clue.

Of course, because I work in electronics, all faults are therefore electrical in nature. Could very well be mechanical, as Mikey has suggested. Also, after the valet incident, that got me to thinking about the typical failure. For most people, they report just the dash lights, but yours seems different as you're also having the parking brake stick in the on position. So between that clue and the current wind direction, I'm now leaning towards a mechanical problem.



To avoid the feel of having to rush, can you disable the parking brake for now? I think if you have the parking brake released and then pull fuses F35 and F52 in the rear fuse box, that should prevent the parking brake from reapplying. Perfect, no, but maybe adequate to let you troubleshoot and repair at your own pace without having to gamble on some potentially expensive repairs that may not help.

 

This wouldn't hurt, and is free to do. As far as cleaning up this connection, the primary contact area is where the cable lug is clamped against the body. Clean up those two surfaces and then apply a light coat of grease on both sides to keep corrosion at bay. Dielectric compound, the stuff used on spark plug boots, is perfect for this. The bolt itself? That just provides the clamping force to hold the lug against the sheet metal. The bolt may carry some current, but that's really more of a secondary path.

Back to the flickering lights. Were they worse at idle, smoothing out at higher RPM? This makes me wonder if your alternator is pumping out excessive AC ripple. One bad side effect of AC ripple is the voltage regulator can get tricked into thinking the battery state of charge is higher than it really is.

This is super easy to check. Set your voltmeter to AC volts, not DC. Connect the test leads as close to the alternator as possible. You'd think the location wouldn't matter, but it does. It can be tough to connect the leads directly at the alternator due to poor access, but you can probably get reasonably accurate results from the front power distribution box. With the engine running, record the AC voltage. Try various combinations of RPM and electrical load. Anything more than 0.5VAC indicates excessive AC ripple, usually from a failed diode in the alternator.

It can also be caused by battery problems, too, as detailed here:


https://www.motor.com/magazine-summa...tery-of-tests/

 

12.4v when I left work today. I measured AC ripple too. At the battery, so it's not definitive, but it was only 60mV.

Slog through bumper-to-bumper traffic for about 45 minutes, so a lot of nearly-idling.

Thankfully, when I got to where I was going (not home), I bypassed the park brake. When I started it up 2 hours later, Park Brake Fault and Cruise Not Available. I didn't check the battery voltage before, because it was POURING rain.

Let's talk about climate control modules... I've repaired mine twice now. Rebuilt a trace once, resoldered the ground pad of one of the big MOSFETs. I replaced the DCCV at the same time as the first CCM repair. Well, it's been on the fritz for a few weeks now. Same thing happened last year when it got cold and wet. Well, I replaced the fuse under the hood that it keeps blowing (a 10A) before leaving work. Boy, it was nice having no fog on my windows for 20 minutes! It eventually blew the fuse, though.

What's the point of this? I read somewhere on the forum that climate control computer problems need to be ruled out when trying to diagnose battery/charging issues.

Oh, and I lost #3 ignition coil today as well! I have a new one waiting to go in, so no big deal.

It's a good thing this car is so damn pretty

Ken

 

The Bosch DCCVs just seem to fail. When they do it's something like chance how soon it takes out the CCM.

jaguarclimatecontrol offer a fix with some sort of fuse - resettable I think.

 

Interesting comment, if the climate control can affect the charging system. I'm not sure, but I have had situations where one system was drawing excessive current and pulled down system voltage. The current flow wasn't bad enough to blow the fuse, though. The battery voltage may still be fine, but individual circuits downstream of a branch of the fuse panel could be affected.


From the cheap and easy department:


1) Try undoing the connector from the DCCV. This will eliminate any current draw through the DCCV. The two internal valves should spring open to the full hot position and you'll have max heat. Manually turn the fan way down as needed. You may have to crack open a window to regulate the cabin temperature.

2) Remove relay #7 in the front power distribution box. This disables the aux coolant pump. Maybe the pump is blowing the fuse and/or drawing down the system voltage, not the DCCV.


I don't think selecting OFF at the control panel would do the same thing as removing the DCCV connector. With OFF selected, I'm pretty sure the DCCV solenoids are still energized to shut off coolant flow. Also, you'd have no defrost action available, which is a safety issue.

 

If it turns out to be the board, again, I'm going to get one of theirs.

I read the same thing about the Bosch valves. Not sure if it's really just the same, but I got a Motorcraft instead:

 

There do seem to be fewer reported problems with the Motorcraft DCCVs vs. the Bosch DCCVs. I decided years ago that when my original factory DCCV shows signs of giving up the ghost, I will also get a Motorcraft replacement. I guess I have been lucky thus far since my factory DCCV is still going strong....

 

So, I've learned something valuable about my climate control issues... I pulled relay #7, and the climate control fuse hasn't blown in a week. I have a dry cabin and no condensation now . It's not quite as warm as I'd like, but it's not really cold right now anyway. Furthermore, it appears I've found my (very slow) coolant leak: the aux coolant pump has orange gunk on it. So, even if the pump is fine electrically, it's leaking and must be replaced.

Quiescent drain hasn't changed, but the operating drain is lower - evidenced by the fact that the battery is getting a better charge now during my drive to and from work. I'm parking with 12.6-12.8v in the battery. The Park Brake Fault warning has not gone away on its own, though. I'll pull the battery cable today to reset it, and see how it goes. I've been charging the battery every night with my CTEK. This week I'll be buying an amp-clamp and a DVOM with data-logging features so I can record the drain as I am driving.

Ken

 

Still have enough drain (or battery failure) that i'm reading 12.4v after work. Short drive gets me back up to over 13v. Charging is good. Going to charge the battery this evening then disconnect it overnight and check in the morning. Should tell me for sure if battery or drain.

Ken

 

Charged up the battery when I got home last night, then disconnected it at 13.2v. This morning, it was at 12.9v. After being disconnected all night, I got the EPB calibration prompt when I turned on the car.

When I got to work it was 12.6v. Compared to leaving it off the charger at night (or during the day), which generally leaves the battery at around 12.4-12.5v.

Apart from doing a run-down test on the battery (which I can do), it seems like there is a parasitic drain that is taking the battery down.

 

I did something more quantitative last night. I have a circuit I built which allows me to create a constant amp-draw through a voltage regulator. I set it for 4A. The battery SOC chart I could find basically says that for every 1/10 volt drop, you've lost about 10% of battery capacity. If a 90Ah battery is supposed to be able to supply 1A for 90h, then it should be able to supply 4A for 22.5h. Every hour I should see about a 4% drop in battery capacity, or something around .044v drop.

I charged the battery, knocked off the surface charge, then disconnected the battery from the car, hooked up my circuit, and let it go for 2 hours. The results were almost exactly as predicted:

Initial Voltage: 12.79v
After 1h: 12.74v
After 2h: 12.69v

I had enough parts to build another circuit, so I did while the experiment was running, and hooked it up in parallel at the 2h mark.

Total draw: 8A
Initial Voltage: 12.69v
After 1h (3h total): 12.60v
After 2h (4h total): 12.51v

It looked like the battery was discharging as expected. Reconnected the battery and left it on the charger overnight. It was floating at 13.2v this morning. Drove to work, but had to make a stop in a different building for a quick errand. Parked, but bypassed the EPB. Quick run inside and back out took 2 minutes. When I got back in the car, got "Park Brake Fault" and "Cruise Not Available". So far, this has been 100% correlated with low battery voltage. This morning, typical for the Pacific Northwest, I ran with headlights, seat heater, windshield wipers, demister (on and off), rear defroster, radio. That's a substantial amp-load...

Tomorrow I'm going to try and run without anything but headlights and see how it goes. I've got an amp-clamp coming so I can take current readings with all the electrics running. Until then, I'm left to attempting to eliminate possibilities. I feel like I've eliminated the battery as a culprit, though.

Ken