Hi all,

In my continuing effort to track down the cause of our inoperative Adaptive Cruise Control, tonight I disconnected the negative battery cable, then disconnected the ECM electrical connector and flushed both halves with electronic cleaner spray. I used a can of compressed air to help dry the connectors, then allowed them to air dry further. While they were drying I took the nut off the ground stud on the right inner fender and cleaned the stud, wire eyelet/ring terminals and nut, then reassembled.

I reconnected the ECM, then reconnected the battery. Upon restarting the engine, the CRUISE NOT AVAILABLE warning was still present, but additionally a new PARK BRAKE FAULT warning showed up.

I tried the basic EPB reset process with no success: while pressing the brake pedal down, turn the EPB On-Off-On.

I followed the longer EPB recalibration process in SDD (which begins with pulling the EPB fuse or disconnecting the battery), again with no success.

I scanned for DTCs and got C1802, "Greater than expected travel for measured current draw (motor current draw compared to expected number of turns).

I tried the calibration process again, but no go.

I cleared the DTCs and rescanned, and the C1802 did not reappear. But after following the EPB calibration process again, I still have the PARK BRAKE FAULT warning.

I used SDD to put the EPB in the service position, and I could hear the motor running. I then repeated the EPB calibration process, but the warning is still present.

Does anyone have any ideas as to what I may have done while disconnecting and cleaning the ECM connector and ground that could have caused an EPB fault?

Thanks in advance!

Cheers,

Don

 

Hi Don - what kind of battery voltage do you currently show?

 

Hi abonano,

That's a great question - I'll have to check it tomorrow. One of the issues I haven't tracked down is that SDD shows the battery condition symbol as Yellow, and I assume it should be Green. It has always shown Yellow, even right after I replaced the battery. My assumption is that either I have a charging problem or high resistance somewhere in the battery power circuit to at least some area of the car (to the ECM, for example). Thanks for reminding me to check!

Cheers,

Don

 

Hi abonano,

Following your suggestion, I measured the voltage at the battery yesterday morning, before the car had been started, and it was 12.33V. We drove the car to church, and then I drove it a few miles to tennis, then the car sat overnight.

This afternoon, I measured 12.49V at the battery before starting the car, then watched as my wife started the engine. The meter dipped to 11V while cranking, which isn't good, since it may mean the actual voltage is sagging below 11V. Once the engine was running, the voltage at the battery terminals was 14V. This battery is only a few months old, so I assume I have a charging issue.

I'll plan to go through all the battery power connections and clean everything, check resistances from connector-to-connector and also check the battery ground cable for resistance.

I spent some more time with SDD tonight and couldn't clear the PARK BRAKE FAULT. I ran the EPB On Demand Self Test and it failed twice. I tried setting the EPB to the service position again and I can definitely hear the motor running in the rear. I've tried recalibrating the EPB by every method I can find in the Workshop Manual, JTIS, SDD and a TSB, but the PARK BRAKE FAULT persists.

All other ideas welcome!

Cheers,

Don

 

11V while cranking should be OK

 

Hi JagV8,

My concern is that my meter can't react instantaneously, so if I saw 11V on the display, the actual voltage may be somewhere in the 10V+ range. Since the ECM is triggering the ignition and the car starts just fine, I assume the voltage isn't falling too close to 10V. But as far as you know, 11V while cranking is normal on an X350?

Thanks,

Don

 

This is a shot in the dark but what about disconnecting the battery and touching the cables together for a minute or two?

If that does not work I would live with it for a while, since as you are aware this Jag is subject to some anamoulus symptoms and the message may disappear after a while.

 

Hi meirion1,

That's a good shot in the dark and it's funny you mention it now because I thought about that "reset" technique earlier today. I knew folks with X308s had found it useful, but I couldn't recall if it was safe for an X350, so a couple of hours ago I just disconnected the battery to let it sit for awhile to see if some of the stored memories might clear. With your encouragement I'll try touching the battery cables together for a couple of minutes and report back.

Cheers,

Don

 

Update:

I first tried disconnecting the battery for a couple of hours. When I reconnected the battery, the message center on the Instrument Cluster showed APPLY BRAKE, indicating that the EPB was in calibration mode. I held the brake pedal and pulled the park brake switch up, and PARK BRAKE FAULT appeared again in the IC.

So I disconnected both battery cables and touched them together for over 1 minute, then reconnected them and tried again, with the exact same result. The EPB module appears to be putting the system into calibration mode, but as soon as the console switch is touched, the PARK BRAKE FAULT appears again.

I'm going to study the schematics to see if there is any connector or other component I could have disturbed in the engine compartment or trunk that might have caused this new fault.

Thanks meirion1 for the idea. More ideas welcome!

Cheers,

Don

 

Don,

I know that you have checked your battery but here is what I found searching the forum under S-Type regarding the EPB.

By Ridgerider:
"Talked to a Jaguar tech today and he confirmed that if the battery had dropped below 12 volts even with a recharge I would likely have to do a "hard reset" to reset the parking brakes. Came home disconnected the ground from the battery, touched the ground cable from the frame to the hot post to discharge the electrical system, reconnected the ground to the battery after a few min, put the charger on to make sure I had 12.5 or better volts and cranked the car. Brakes released fine. (Be careful not to short something out, you can take the battery totally out of the loop if you feel better about it, what you are doing is grounding the positive leg of the electrical. Just don't have the battery connected.)
Will be getting a battery to put in it tomorrow. Now new battery has solved the problem."


By wigginout66:
"The battery was a Jag battery and being the second owner after a lease turn in, I suspected this was the original battery. Pretty good life 2005 - 2013. I took it to my local autozone, had it tested and while the battery was still good, it only had 40% charge. He offered to charge it but given that it was 8 years old, I live in New England and it was just the start of winter I opted for a new one. $150 later, I had an exact match, right down to the holes for the positive post cover and vent tube. Once installed, I was VERY happy to see my problem was now fixed.

I did have to do the reset for parking brake, radio presets, clock and power window auto up. My radio did not ask for a code and did not lose my seat presets (go figure).

Who knew that the battery could have enough juice to start the car but not enough to work the parking brake."

 

Thanks lcmjaguar,

I've tried touching the negative and positive battery cables to do the hard reset per meirion1's recommendation. Based on the posts you found, I'll try giving the battery a good charge. Fortunately, my EPB is stuck in the released position, so I don't have to go through the hassles others have faced.

By the way, I set the EPB to not automatically engage using SDD, but in trying to figure out this current problem, I found a statement in one of the manuals:

"If the parking brake is required to be permanently released press and hold the parking brake switch down and at the same time remove the key."

If anyone is willing to try that and let the rest of us know if it works, it would be a good trick to know.

Cheers,

Don

 

Don,

Here is what one member has stated...

The EPB is automatically applied when the key is removed from the ignition switch. If you wish to keep the EPB off, press and hold the EPB switch down and, at the same time, remove the key. Caution: Take care that the vehicle is safely parked to prevent it from rolling if you wish to leave the EPB off. The warning indicator in the instrument panel will remain on for a short time if the EPB is applied when the key is turned to position 0 or if the key is removed. If the battery has been discharged or disconnected the message APPLY PARKBRAKE will be displayed when the ignition is next switched on. Depress the footbrake and pull the EPB switch up to apply the EPB. This is required to reset the EPB system which will now function correctly.

 

Thanks lcmjaguar, that was the very first method I tried. I think there are at least three versions of how to reset the EPB, plus a longer procedure for recalibrating the EPB. I've tried all the procedures but the PARK BRAKE FAULT persists.

Thanks again!

Cheers,

Don

 

It sounds like you may have seen the attached, but if not...

 

Hi u102768,

Yes, I have that TSB and I have followed the EPB calibration procedure, but what I have not done is attach a battery charger to the battery while doing the calibration. The TSB mentions connecting a Midtronics PSC-550 power supply, which I don't have, so I did the procedure without it. I just googled it and it appears to be an expensive battery charger and power supply for use when reflashing ECMs:

Midtronics PSC-550SKIT PSC Series Power Supply / Battery Charger with Soft Protective Carrying Ca: Auto Body Tools & Auto Equipment : Walmart.com

I'll try using my battery charger to see if it helps. I appreciate all the ideas so far!

Thanks!

Don