Ok , Im new to the forum but well versed in vehicle repair, except for Jag. lol.
Ive owned mostly American cars but went thru a 328 couple years back .
The scans
What I have is a 07 XK Vert with 91K miles in Physically good condition for a stolen recover, oh well.

Ive been putting it back together as it was partially stripped. It runs and drives with issues.

My starting question. The scanner is telling me that almost every module is having communication issues. I am getting some codes.
The question becomes is there a priority for diagnosing these issues ?

For instance , the EPB refuses to communicate or reset and Ive done all the tricks , followed the manual except for doing the pinout checks which are next.
My intuition tells me that until the EPB is talking the rest of the issues are mute. Correct ?

I wont post codes at this time cause there are A BUNCH from all the other modules. Looking for a starting place. Im good a tracking down and fixing things , just never done a Jag.

Any pointers would be appreciated

 

Number one step; make absolutely certain the battery is COMPLETELY healthy and fully charged.

 

Done and thx,

The first scan , I had a Fluke DVM hooked to the batt terminals in the back seat with the top down and everything off, batt showed 12.8.

Sure enough , opened the driver door , turned ignition on, saw voltage go to 12.4. Most of the modules reported battery issue.

Erased the codes, hooked a 20 amp charger to the terminals, got voltage up to 13 and redid the scan. Pretty much the same results without the battery codes.

Step 2 ?

 

When you say "got it to 13v" what do you mean?
9/10 the EPB issue is caused by a low voltage or activating current. that 1/10 chance either the module is kaput or a wiring issue.
Do you have the workshop manual?

 

With charger going , i monitored the batt voltage and as soon as I saw 13 volts I redid the scan. Same result on EPB , no comm

Yes on workshop manual.

 

It's almost always the battery.

Have your battery load tested for free at your local national chain auto parts store.

 

With Battery on a 40amp charger, voltage showing 13.9 Ran a 100Amp Load test with charger disconnected All good.

Cleared all codes. Reran Scan. Almost every module came back with cant comm with EPB, this is while batt is connected to charger and on 40amp charge.

 

As you can see from my sig, I've been through a number of BMW's. This is an easy car to work on, similar to the BMW in difficulty (meaning not very). Absolutely nothing weird about it, no mysteries. If you have the service manual, the electrical guide and a JLR compatible reader, you're most of the way there: Denso Ignition, fuel and ECU. ZF transmission. Tendency towards vacuum leaks after 15 years, and the (many) bushings weaken -- though they're Lemfoerder, probably the best OEM out there. But 15 years is awhile.

From the info you've gathered, can you define whether the MOST and CAN busses are communicating ? The MOST in particular is a ring and any break will disable all links. A recovery can easily have breaks in the bus(ses). Figure 21.1 -.3 in the electrical guide have layouts of the two CAN busses and the MOST bus units, at least for VIN's up to 9000 or so.

Do you have SDD? And does your OBD reader support full JLR codes?

 

Ive just started down the road of investigating the busses..Still getting the straight, JLR I assume is Jaguar Land Rover. If so, Yes, I bought the SW and Installed it on a Autel Digilink seems to read everything until the cant comm message shows up.

Yes have the service manual, all 2000+ pages and the electrical which I just started tracing the EPBM circuits. Unless you can suggest a better place to start.
No on SDD, read up on it but that tool is foreign to me.

Scanner reads 21 different modules. probably 8 or so seem to be OK, rest have issues , mainly cant comm with epb.
Headed to junk yard tomorrow, they have a 07 coupe , see if I can get a favor and borrow the EPBM

 

To check out the CAN,

check the two communication circuits. Locate the CAN C+ (or HSCAN + circuit) and CAN C- (or HSCAN – circuit). With the black lead of your voltmeter connected to a good ground, connect the red lead to CAN C+. With the Key On, Engine Off, you should see about 2.6 volts and fluctuating slightly. Next, connect the red voltmeter lead to the CAN C- circuit. You should see approximately 2.4 volts and fluctuating slightly. Other manufacturers show CAN C- at approximately .5 volts and fluctuating Key On Engine Off.

Fig 21.1 EPBM is correct ? Yellow and Green wires

 

One more suggestion, may not help at all but worth trying. Disconnect the battery terminals and touch the leads together. This resets all of the electrics and errors and has often helped other members solve glitches like this.

SDD is JLR’s previous factory diagnostics software and quite thorough yet slow compared to aftermarket scanners but it might help pinpoint the source of the issue assuming a module’s indeed failed on the network. Sometimes faulty earth points can cause problems as well as harness connectors.

 

AND check the voltage without the charger attached and after “resting” (not being charged), overnight.

 

As Im prone to if its working it aint broke , except when its only working half way.

So, took yalls advice and took the 50 Lb damn battery to the battery store and had it tested. Battery is about 1 year old, but sat up for a while and was flat when I got it.

Battery is rated 900 CCA, sucker is heavy. They ran an extreme test on it at 1000 amps and it held up fine. So much for battery issues. If only it could have been that simple. Didnt hurt to check.

 

Did the terminal touch, no joy.
How do I get SDD and whats needed to make it work ?

 

SDD is a bitch to setup and learn. Calling it primitive is a compliment. If you don't have it, try the below before you go down that particular learning rathole.

Better choice first is to get a OBD that reads JLR codes. I use an Autel Ap200 dongle with the JLR download. $69 lately, with the first manufacturer included (JLR, of course). Others are $24 (?) after that. Runs through Droid or IOS. Covers all the ECUs for your model. Has a few service functions, but you're not there yet.

BTW, have you physically examined the key ecu's throughout the car, as well as the 3 fuseboxes? Stuff gets removed in stolen cars. I've attached a summary diagram that locates them all. Note that the attached guide cross references to the electrical manual. So if you find, say, an ECU in the electrical manual, or any other connecting point, you can search the connector ID in the attached diagram .pdf. Very helpful for locating ground points, wiring locations etc.

 

Did the above Both CAN C are correct at about 2.5 volts connector disconnected from EPBM

Removed EPBM , inspected connectors all clean and straight. Took the module apart and inspected the board for solder cracks or burns, all looks good.

Next ?

 

I’ve not had the best luck with non-SDD readers. Jaguar’s software’s far from perfect but some things it does very well and better than any alternative.

No idea if your tool provides percentages of which DTCs likely the cause of the fault. One thing SDD does is tell you which DTC’s likely the cause of all the others so you can start with that first.

I’ve trouble shot modules and have found one faulty one or harness connector or earth can cause a cascade of other failures. Once the primary’s resolved all others clear up as well.

One time I had canbus issues the main dealer couldn’t figure out and I diagnosed it
to irregular voltage from the alternator. Replaced the alternator and all
issues resolved.

 

MudDog,
You have gotten excellent recommendations from some of the best on this forum.
Following the thread, each recommendation has been a gem.
Kudos for actually pulling and testing the battery. To that add, clean the terminals with the proper wire brush tool.
Use a cigar lighter/plug-in voltmeter to monitor system voltage. An open door causes the electronics stack to stay energized.
Battery voltage drops quickly with a door or two open.
Retrace all the steps recommended.
Find a friend who is competent in SDD.
Is that location Mobile Alabama? Roll tide and all of that?

 

YEP ON ROLL TIDE !!!! yes on Mobile

Thanks,

Yes on battery drop, I hook up a charger if door is going to be open for a while. Keeping volts above 13.

Reinstalled EPBM this morning and then the battery. Redid Scans , same results.

 

Just a thought: As you state stolen vehicle recovery, look at the wiring and connector to the parking brake actuator. The connector is adjacent to the right rear suspension.
Parking brake can be deactivated by applying 12V at the connector. Handy if you are trying to steal a Jaguar. A residual problem might impact EPBM operation.

SDD: I use a Mongoose Pro purchased by phone directly from a sweet lady that I imagined to be Mrs. Drew in Ann Arbor.
No longer available, many folks have had success with other devices. I recommend jumping in with SDD. A local collaborator may save much anguish.
Keep us posted on your progress.