I have a 2006 Jaguar S Type 3.0 with only 45,000 miles on it. When it rains heavily, the car develops a parasitic power drain and kills the battery. It only happens with heavy rain. Going through the car wash or snow doesn't cause the problem. I am almost positive it is the front module in the car because the reservoir that fills with water from the windshield was clogged with leaves and dirt. I think the water was overflowing from the reservoir onto the front module and causing the power drain. I cleaned all of the leaves and dirt out of the reservoir and now the water drains down to the ground with no problem. However, I would like to take a look at the front module to see if it has been damaged from water over the years. My understanding is that the front module is right by or under that reservoir which would explain it getting wet and causing the power drain. I read in this forum where someone had the exact same problem with the battery dying when it rained and he checked the front module and the module and wires connecting to it was damaged from water over the years. I checked the rear module in the trunk and it is bone dry. That is why I think it is the front module that has gotten wet over the years from the reservoir being clogged and it now malfunctions when it gets wet and/or the wires connected to it might be damaged. I have two questions:

1.) What is the exact name of the front module? Is it a control module? Is it a computer module? Is it an ECU module? I need to know what kind of module it is to order the correct part.

2.) How difficult is it to get to the front module to replace it? My understanding is that if I take off the front passenger side tire and remove the wheel well lining, it will be located up in that area and below the reservoir from the windshield. Is that correct? If anyone has a picture of where the module is located that would be very helpful.

Thanks!

 

There is no resivuar under the s type windscreen .
Or undergaurd . Although there is a coolant overflow resivuar under the gaurd of the xk ,
The FECM (front electronics control module) is within the cabin . The ECM is the only module under the wind screen . But it is relatively well sealed .
Although I've seen water ingress with in the plugs before .
You do not want to be swapping that out without Specalist help trust me .
The risk is rendering your car a large paper waight or lawn ornament. .
And regardless it does not sound like it needs replacing any how .
Maybe just resealed .
Or It will be somthing else !
You could try watching the videos on YouTube to learn how to pin point your parasitic drain with a multi meter .
Such as Eric the car guys vidio explains this well .

 

I did a parasitic drain test on all of the fuses and none showed a power draw when the car was off. This electrical problem where the battery dies only happens when it rains (I have a battery protector on it now so it never completely dies anymore). I am almost positive it is the engine control module and/or the wires connecting to it that are getting wet from water coming down off the windshield when it rains. The reservoir I am talking about is where the rain water drains down from the windshield and then it gets funneled to the ground. There is one on both sides of the car and the rain water goes into them and then out the bottom of the car. My understanding is that the engine control module sits under that reservoir (for lack of a better term) on the passenger side and water sometimes gets on the engine control module from the crowl not being sealed tight against the windshield. I cleaned that reservoir on the passenger side because it was filled with leaves and dirt and the water was not draining down quickly to the bottom of the car. Today it poured rain here for hours and my car started right up when I drove it home after work and it did not have any parasitic drain. I think that reservoir being clogged had something to do with it and the engine control module was getting wet. I also sealed the crowl tonight with black guerilla tape that is super strong.

Okay, so I will not attempt to replace the engine control module, but I would like to take a look at the engine control module to see if there is any water damage to it or if any of the wires leading into it have water damage. How do I get to the engine control module on a 2006 Jaguar S Type? One guy said he took off the front wheel on the passenger side and then went in through the wheel well to the engine control module and found that a lot of the wires going into the engine control module had become damaged from rain water over the years. Another guy said he removed the glove box to try and get to the engine control module. Which is the best way to do it? I would like to take a look at it and the wires connected to it to see if they have been getting wet. Also, my car's headlights sometimes briefly come on and then go off when the car is shut off and the alarm is on. Again this only happens when it rains. Something must be getting wet.

Thanks for the help!!

 

I think the words (drain channal ) are what you mean .there is no resivuar as such .
And No neather of the instructions you have been given are correct ,
You must remove the wiper arms , then remove the windscreen cowl .
Then remove the pollen filter then the pollen filter box Four bolts one is inside the pollen filter box . and wiggle it out .
Then remove the pollen filter box heat sheald ,4 nuts.
The ECM is then exposed . The pollen filter heat sheald has a bead of sticky sealant to redirect water to the side of the ECM . It's very rudimentary protection and could easily be improved on .
There is no need to remove the glove box . The under dashboard cover exposés the back side of the ECM and carrier bracket ,
But all the seals and wires are on the engine bay side .
Heads up also the harness is fixed with a tamper proof tork's bolt . These are obtainable .

 

On mine the PCM (aka ECM) is fairly easy to get at by removing the glovebox BUT be sure you need to do this. Unless it is wet you are wasting your efforts.

It is OK to remove it and put it back but do not be tempted to fit a different one without understanding anti-theft and the OE tool required.