on Friday my car failed to start it just bleeps saying and flashes brakes

on the diagnose i get "communications failure Parking BRake Control Module

I just fitted a spare PB Module and it made no difference -

12.4V on my battery - using a new Yuhasa 019 and a 6 month old Durecell 019

Any ideas that work will get beer tokens!

 

A battery registering 12.4v is nearly at 50% useable capacity. Not enough power for these cars.

 

yes but why just the PBM module?

 

The module operates between 9v and 16v so a battery showing 12.4 volts is fine .

 

Also Ive tried a fully charged boost pack and that didnt work

 

Could be a bad earth somewhere?

 

Your answer shows your lack of experience with the car. the EPB is one of the first modules to report an error condition, on weakened battery. Any electronic component needs power. P=IE. And at 50% capacity, your available current is severely diminished. There are numerous references available for you. I prefer those provided by Varta.
Or ignore the very first test in the workshop manual... then enjoy the centre screen not powering up.

 

It must be related but 2 days before this happened my remote lock button stopped working so on checking the microswitch was unsoldered - I fixed but as the battery had been out of the remote the key no longer worked so I started reprogramming it and it worked fine - then the parking brake fault happened?

got to be related right?

No its not recognising my key at all!

 

The problem with a battery with a resting voltage of just 12.4 volts is that it has either lost some of its rated cold cranking amperage capacity or it is not being properly charged by the alternator and ECM. With a battery in that condition, the voltage while cranking is likely to fall below 11 volts and the amperage may be insufficient to rotate the starter or to properly power the ECM and other critical modules. This can trigger all manner of random diagnostic trouble codes in multiple modules. Some circuits are more sensitive than others.

I would suggest having your battery and charging system tested with a professional analyzer.

A common cause of insufficient battery charging is corrosion on the many battery power and ground connections between the battery in the boot and the alternator and starter in the engine bay. The corrosion that forms on the aluminum eyelet terminals, studs and nuts is a microscopically-thin layer of aluminum oxide, which is an insulator. It may be invisible to the naked eye, but collectively, the added resistance at many or all of the connections can prevent the battery from charging properly. Basic maintenance on Jaguars is to periodically go through all of these connections, disassemble them, clean them with a small brass-bristle brush and zero-residue electronic contact cleaner (I use CRC brand), dry, then reassemble. Note that the torque spec for the aluminum nuts is very low at just 6.5 ft. lbs., which is barely more than hand tight. Many of our members have snapped ground studs off of the body by overtightening the nuts. The first thing I usually check is the engine ground strap, which sits in a vulnerable position and becomes corroded and/or contaminated with oily gunk.

Cheers,

Don

 

Good information and listen to these guys about the voltage and battery. Caution with those boost packs. Your sending thousands of amps in a short time and much can be damaged. The road side repair guys that use them could care less because once your car is started they get paid and leave.

Start with a battery replacement and post back with what's changed.
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I fitted a new Yuhasa 019 in it on Saturday and that made no difference Ive even tried a fully charged Duracell 019 jumper cabled Pos to Pos and Neg to Neg and that made no difference either

 

I agree I have no idea so I just jumped it from my other jag and tested it on 13.5Volts

 

Mine starts easily at 12,0

 

I agree!!!!

 

Car is LOCKED out...

HARD reset!!

 

tell me more - I cant clear the codes - they come right back every time!

 

Try as HealeyJag says, "Hard Reset"...

 

should i unplug all my good modules first? or just pull every fuse apart from the 30 Amp parking brake module

 

simple 1st

 

Just disconnect the battery (hard reset) for a few mins.