A long, long battle with my EPB came to head the other day when it failed it's MOT on it.

Some days it will work, others it won't. It happened to be on a 'not working' day at the MOT, which is the mode it has been in for a few weeks now.

I have sought advice about it before, but drawn a blank. A failed battery was number one answer, but a borrowed good battery didn't help.

It will apply, them immediately unapplies. Noisily.

Here's what I know:
-When I bought the car, the recent MOT failed on the handbrake. Forward a couple of days, new discs and pads and it passed the MOT two months prior to me buying it.

- The grip of the brake never really impressed me, it didn't seem to hold the car firm if left in D.

-I inspected the brakes and noticed the pads were not in square or inline with the pins on the back of the pads. I realigned them. No difference.

-A battery and parkbrake reset allows it to work once only, then back to not working.

- Forcing the motor to apply or unapply via the module grey connector and a two wires to the battery is fine. However, it does sound noisy and creaky compared to other cars with the same system.

- If applied using this technique, it will not unapply unless using the 'forced' method to do so. Using the EPB button or the throttle does nothing.

My conclusion is that the motor is OK. The cables all seem to move freely, so that's OK.

The module is the iffy area I suspect, but a second hand one was £95 the other day. A Lot of money for a bad guess.

What is the opinion of the members? I'm really at a point where I'm tearing what little hair I have out now.

 

The 'noisy' bit you mention leads me to believe the actuator is the likely failed item. The only caveat is that you don't appear to have the equipment to properly release the system to the Service Position, or clear any fault codes that have been logged during the failure and tinkering with the brake you have done. Sometimes logged faults can keep the system from performing properly, and the only way to verify that is not an issue is to clear them out and THEN reset the system.

My money is on the actuator, though.

Good luck!

 

Hi manycars from down under ...

Consider this before shelling out for a replacement module. First check carefully the loom wiring and connectors. Many reports of weird symptoms finally nailed by pinched, loose, corroded wiring and/or connectors. Re-test. No go?

Then, lash up two temporary wires - red fused power feed and black earth return - each ending in similarly color coded "suitcase connectors". Then temp splice each into the power and return wires near car's module. Double check and re-test.

Using this method will not help in a case of wiring shorts but in this case, that would have resulted in blown fuse(s) long ago. Where this method shines is it's ability to quickly diagnose open circuits - even intermittent. In these days of serial bus electronics, I have a third temp wire lash up ready for those occasions when you need to similarly test a data bus wire.

Another major benefit of this approach is seen after you remove the "suitcase connectors" and parallel temp wires -almost invisible cut into insulation - although a quick overtape will give you added peace of mind.

Best wishes,
Ken

 

I don't recall any pins on the backs of the pads (?)

I suggest removing the wheels and watching the cables and caliper levers while a helper engages/releases the EPB. I wouldn't rule out a mechanical problem at this point.

A properly operating system will not only hold the car still while in Drive, it will bring it to a surprisingly swift stop!

 

Might be some useful info here, Jason had an R but I expect the actuator is the same.

https://www.jaguarforums.com/forum/s...storage-53003/
https://www.jaguarforums.com/forum/s...r-apart-53753/

 

Yes, should be almost the same. There are some differences of cabling just to cope with the slight physical differences (so parts wouldn't necessarily swap) but in terms of underlying function I believe they're the same.

In case it really is the module, making sure whether it's on SCP or CAN will be essential - see electrical guide for the specific VIN range of the car and cross-check with the module's connectors etc.

A jag-type OBD tool (IDS / AutoEnginuity) would be needed to talk to the module.

 

Hi chaps and thanks for the replies.
Got a half day today, so now have a couple of hours daylight to have a look-see at it all.

xjrguy, old codes could be causing issues. Only a visit to a Jag specialist will tell if that's so or not. I'll talk to one today, to see if I can get booked in pronto, but there are not too many locally that have been recommended to me.

cat as trophy. If I was to insert wires into the back of the connector, at the power on and off wires, would that be the same as doing as you suggested?
I've already got the wires rigged up on large croc clips, as I used a similar method, but with the connector off the module, to 'force apply' the handbrake and to release it again to test the motor. Basically I bypass the module with my way.

mikey. The pins are very small pips that locate into the piston cut outs. I've already looked at the cables and brakes whilst the EPB is being operated. It all seems to move without isssue, except for a screechy, dry noise which is hard to pinpoint. Interesting that you say about the handbrake providing a swift stop. There seem to be too many people who maintain that any RWD car will easily overwhelm the handbrake in drive.

norri and jagV8. I'll read that link in a second, it just won't open at the moment it seems? I did see a module with almost identical numbers printed on it, but as I say, t £95 it was not a cost I want to spend if it could be better spent elswhere on the issue.

I'll report back later.

 

I'd concentrate on the screechy dry sound. Could be the actuator itself.

The comment about bringing to a halt was with the gas pedal released of course. If I'm on gravel the wheel will lock up as we come to a halt.

 

I spoke to a not very local Jag specialist who advised a hard reset first. I explained that I had done this, many times and he told me that I should not be just removing the neg cable. Removing both cables was the correct way to do it. I did this and the result is the same, EPB works first time, then doesn't after that.

mikey, I have been trying to pinpoint the screechy noise, but need another pair of ears or hands. When the EPB is applied it screeches, the screeches in a slightly different tone as it immediately disengages again.
Will have to wait until I can get my assistant to help.

In the meantime, I found this on the web. Mine on/off squeal sounds nothing like this as it's not as vocal, but just seems to have the same issue though.

 

I can't see any point in further tests with croc clips and wires. If you do them, disconnect the module as you don't ant to risk backfeeding the module (at best, at worst the 2 sources of power could fight).

 

I didn't do it afterall. It seemed the same as what I'd already done in my mind and I didn't want to risk the delicate module.

On my next day off I'll have quick look at the workings, weather permitting. If nothing obvious, I'll have to get it to a local Indy to get all codes cleared, get their advice and go from there.
I should have sorted it a while ago, so only got myself to cuss.

 

Hi manycars and JagV8;

The point to my post was to test for broken, poor and/or intermittent power feed or ground return loom wiring and connectors - often suspect points in many of our cars - by adding temp wiring in parallel, before dumping the module. Backfeed? Fighting each other? No, you are only providing a "known good" power path in parallel with the car's existing (but suspect) wiring.

However, I see from further posts your problem is neither permanent nor intermittent. It is cyclical, and therefore not arising from a wiring loom issue.

So, I agree that you should ignore my earlier recommendation. Sorry I distracted you with my initial misread of your problem. Even so, I remain keen to see the final diagnosis and fix.

Regards,

Ken

 

No worries 'cat as trophy', all suggestions welcome.

 

Just a little update.
As it has no MOT, I'm not keen to drive it to either of the specialists that I could normally use. They are are 1/2 hr away and plod will be sitting behind me at every turn, I just know it.

I found out that the local garage has a SnapOn Solus reader, with a variety of chips that allow it to read any car. Not expecting too much but two codes came up. C1094 and C1785.

I'm rather confused about the VIN numbers given for these faults on Jagrepair.com. Mine is a 2005 model or 2006 to you in the US, but the VIN numbers don't match my car. Mine is N36***, but according to Jagrepair the DTCs changed to 7 digits from 2006 on, which as it's a US workshop manual, means 2005 on. VIN N52048->N99999 is the 2006 on model, which is after my VIN? VIN M45255->N13088 is the pre 2006. My VIN N36***is in between.

The codes and their meanings are similar, but not the same, as you can see.
pre 2006
C1094 Parkbrake Apply switch circuit failure
Connector pin(s) bent
Connector loose or corroded
Harness fault
C1785 Parkbrake motor output open circuit
Fuse failure
Connector pin(s) bent
Connector loose or corroded
Harness fault
post 2006
C109400 Primary apply switch circuit Primary apply switch circuit:short circuit to power
Primary apply switch circuit: high resistance
C178500 Parking brake motor output Parking brake motor output:high resistance

He tested the switch via his reader and it came back as working OK when he manually operated the switch on and off.

The suggestion was to pull the cables off the brakes, operate the EPB to free them up. However, I'm just reading through the workshop manual at Jagrepair.com and as soon as it stops p1ssing down, I'll do the checks as per the manual.

 

I think you're mixing up jag MY, USA years and software release years. Your VIN looks to be 2004MY or 2005MY. Don't think too much what that may mean in USA. (Also, USA doc refs should start 18 rather than UK 10 if you're inclined to dig a deeper hole...)

Jag's newer DTCs have 2 suffixed digits being a subcode when available.

I thought you'd said the module wasn't visible on the CAN? Different OBD tool?

 

Not sure what you mean about the module not being visible on the CAN? All I know is the codes that came up on his Solus are the older 5 digit codes, but I am likely mixing up the US and UK differences.

I just found a note in the workshop manual.
NOTE: Generic scan tools may not read the codes listed, or may read only 5-digit codes. Match the 5 digits from the scan tool to the first
5 digits of the 7-digit code listed to identify the fault (the last 2 digits give extra information read by the manufacturer-approved diagnostic
system).

That explains the 5 digits, but either way, it's the switch or the motor it seems.

 

I thought you said it works via direct battery wires? If so it's not the motor but has to be the module, the wiring or connectors.

 

Keep in mind the 2005 MY [model year] began at VIN N13089.

Don't be concerned with seven digit codes, if the scantool being used can't read them it will always read the 5 digits, IF it can read more than just OBDII codes.

As I mentioned before, I have found that in some instances the system cannot be reset and made functional until certain codes are no longer present.

Attached is a bulletin that may help sort through it. But I still believe you will end up replacing the actuator.

Good luck!

 

In case this is any help for cable routing etc

 

That's correct, it does operate using wires from the battery. Is that what you mean by not being visible on the CAN?

I've tried to follow the tests in the Workshop manual, but either my ohmmeter is duff or I'm not able to use it correctly. Probably the latter.


xjrguy, I'll have a read through that in a mo. Thanks.