Looking for some help on a battery drain.
2005 S Type R.
I have a 0.660 milli-amp drain.
This is because the FEM is sending a logic earth to the 4 Power system relays in the boot.

I have attached wiring diagrams to save people looking them up.

Measuring the logic earth from the FEM, i am seeing 0.200 mA.

I am seeing 0.660 mA on the battery earth. This is because the 4 relays are energised.

If i remove the 4 power relays after the car should of shut down ( 40 Mins ) then the battery drain drops to 0.040mA ( more than acceptable. ).

If i remove fuse 33 in the primary junction box then the car goes to sleep as it should after 40 mins approx. Even replacing this fuse after the 40 minutes did not wake the car up.

I was using a current clamp to determine when the drain is there.

I have measured every wire going into the FEM, and i am seeing 0.080mA on the white wire in fig 9.2 ( switch illumination B+ ).

I have removed intrusion sensors, unplugged battery sounder. Disconnected trunk/fuel flap switch as this is also fed by F33, but still no different.

I have removed the bumper and inspected the loom for corrosion, i have replaced the instrument pack as the steering column wasn't working, the instrument pack was also sending a very weak earth to the PATS light, which caused it to glow very dimly, only visible at night.

Another thing that i have done is to cut the black orange wire where it splices at the back, this was done to confirm which module was keeping the relays energised.

i have changed the FEM and the REM.

i have changed the relays in the boot, so as to check that none were staying latched when they should of de-energised

The bit that's confusing me is the removal of Fuse 33 makes the car sleep, would really appreciate some help on this, this is my own car.

There are no non standard item fitted to the car.

Thanks in advance. All suggestions greatly received.

 

Guessing... in some way the computer isn't getting a signal that the engine is off and the driver has left the car. I donno... maybe a bad door switch?

 

Check the flap in the ignition barrel is closing when you remove the key, if it doesn’t, the car will think the key is in place and will stay awake.

 

Does your car still have the Transit Isolation Relay installed? IIRC, this relay and fuse F33 (in trunk) are supposed to be removed before delivery to the customer.

See this thread:

https://www.jaguarforums.com/forum/s...rouble-214690/


Slightly different problem with an earlier model, but many of the details are applicable. Looking at wiring diagram figure 01.1, I don't see fuse F33 going anywhere else but this relay. If you're seeing a change in amp draw when this fuse is pulled, that makes me think the relay was never removed.

 

thanks for replying Kr98664 but that F33 is in the rear power distribution box. The F33 that I'm removing is is in the front power distribution box.

 

That is NOT the correct response. You were supposed to have replied about what a genius I am, a gift to humanity, smell nice, so on and so on. Instead, you bring up some arcane theory that I'm less correct than usual...

Moving right along, I'm a little confused about the location of this mystery F33. In your original post, you said it was in the primary junction box (which I missed). But now in your replay(quoted above), you said it's in the front power distribution box. Boy, that must sure be embarrassing to publicly get an important location all wrong. So before I keep digging, I want to make sure I'm at least digging in the correct spot.

One more quick question: What led you to pull fuse F33 (wherever it is) for troubleshooting? It's great that you found that, and how it affects the car entering sleep mode. I'm just curious if you had some clue that led you there.

 

Sorry KR98664 you smell nice.
I quoted incorrectly as you pointed out. F33 is in the Front Power distribution box.

The reason i pulled this is reading about battery drain, i used the method of measuring millivolts across the fuse. Which ( not teaching you to suck eggs) shows if the fuse is drawing current without disturbing it.

I have been using an SDD clone to program bits.

Do you think ive corrupted something along the way?

 

Confusion reigns supreme now.

In your first post, the wiring diagrams you attached were for the Switched System Power Distribution, and you talked about those four relays in the trunk. You also included the downstream wiring diagrams (through F33 in the Primary Junction Box inside the cabin) for interior lighting and the door locks.

But now you're saying you meant F33 in the Front Power Distribution Box, under the hood. That fuse only goes to the Engine Control Module (ECM) and Transmission Control Module (TCM). Had you been on another one of your 3-day Mountain Dew benders when you included those seemingly unneeded wiring diagrams? Were you just as confused then as I am now?

If we're really talking about F33 under the hood, it seems like either the ECM or TCM isn't going to sleep. That's a whole 'nuther line of troubleshooting versus what you had tried earlier. I think at least one of us is looking in the wrong place...

 

My oh my KR98664 have you lost weight? I like what you've done with your hair.

Anyways back to the car.

Just to clear up my muddle.

F33 primary junction box is the naughty fuse. With this removed the car goes to sleep. Hope that clears things up.

 

Thanks! Not much to work with these days, but I've found a screen over the shower drain really helps conserve what I've still got.

Got it. Today it's F33 in the primary junction box. Might change again tomorrow, but for now we're going with primary.

It's very confusing that pulling this particular F33 has any effect after the car has supposedly gone to sleep. The four Switched System Power (SSP) relays in the trunk should all relax by then. There shouldn't be any power at F33 by then.

SSP relay #3 (R11) is the one that feeds power to F33. Yet the four SSP relays are energized in parallel. I don't see any way that only #3 would be energized and not the others. Something just ain't right.

How about confirming whether SSP #3 is actually staying energized? Two ways to do this:

1) Remove the relay while energized and you should feel a slight click as the electromagnet loses power and the contacts spring open. Reinstall the relay, wait for sleep mode, and then pull the relay again. If still energized, you'll feel the click again. Please note this isn't conclusive, as you'd get no click if the relay was physically stuck closed.

2) Remove the relay and pop off the cover. Reinstall just the base. With the cover off, you can see if the electromagnet has pulled the contacts closed. Let the car go to sleep and then observe the contacts.

Another idea:

Measure the voltage at F33 with the fuse installed. Wait for sleep mode and check the voltage again.

 

Is there any chance you have a LoJack or some off brand of this type of guardian?

 

Hi Kr. All 4 relays remain active. As you rightly say F33 is powered from 1 of those relays.

bit of progress today, with FH59 disconnected from the FEM the car sleeps. This has the SCP wires in it. I have removed power was and horn relays and shorted the bonnet/hood switch and it still doesn't shut down.

Today I'm going to disconnect modules on the SCP network and see what happens.

Thanks for you interest.

 

Sorry whats a LoJack ?

 

I think it's a radio/wifi-type of device to report if a vehicle is stolen (or used wrongly).

Point being it would consume power and not be on any of the elec diagrams.

 

Autocorrect strikes again? What was this supposed to say? Just trying to piece together all of the little clues.

Looks like I misunderstood the situation from the very beginning. Somehow I had the impression that only a single SSP relay was staying closed, but you clearly said it was all four. Sorry for any confusion.

How does this scenario sound? Something downstream of primary fuse F33 is sending an erroneous signal to the FEM. In turn, this module thinks the car is not ready for sleep mode and as programmed, it commands the four SSP relays to remain energized. Pulling F33 breaks this feedback cycle. Is that basically what you were thinking from the get-go? Sounds like you were already hot on the trail until some mouth-breathing knucklehead confused things...

If you've already waited long enough for sleep mode and then pull F33, does the car enter sleep mode right away? Or does it wait another 40 minutes? Not sure how to interpret that either way, but maybe this clue will help.

 

Yes KR, pulling f33 breaks the cycle, but it doesn't sleep straight away, it takes circa 40 minutes.
I have removed the other fuses that are fed by the relays in case it's somehow back feeding, but it's still the same.

I have a wire and a test lamp connected to switch system powered fuse, this is a simple way to tell if the car sleeps.

This morning, car been sat there all night and it's gone to sleep ! Also a quick feel of the 4 relays confirm that they are cold, therefore the cars been asleep for a good time.

The above auto correct should be ' horn and powerwash relay ' these are on FH59 on the FEM.

 

Okay, I think I understand what you've been saying all along. This one is definitely a headscratcher.

Look at wiring diagram figure 01.6. Just downstream of Primary fuse F33, you will see the circuit branch into two legs, with one side feeding connector FC33. I wonder how difficult it would be to find this connector. If you could disconnect it, you'd take out one branch and that would help isolate the drain. See page 17 for the location on a RHD car. FC33 is described as "16-WAY / GREEN / CABIN HARNESS TO FASCIA HARNESS BEHIND INSTRUMENT PANEL, RH SIDE".

Another thought is to park the car in a totally dark location, such as in a closed garage with the lights off, or inside Nancy Pelosi's heart. Open all the windows and glove box, and then wait until the car should have gone to sleep. In the darkness, look for any lights that my be glowing dimly.

Try unplugging the fuel flap relay R8 in the trunk.

Try unplugging the fuel flap switch/trunk release switch pack. This module has some electronic wizardry that may be leaking, for lack of a better word.

Wish I had something more concrete to offer you.

 

Thanks KR. I have already split the connector at F33, at FC33-14 and depinned it. Car stays awake.

Moving forward today, disconnecting FC17 takes the IP, AUDIO UNIT and steering column out of the SCP network. Car still stays awake.

That leaves the following ... FEM, DDM, DSM, FEM, DAMPING MODULE, and NAV.

I disconnected the DDM, NAV MOD AND DAMPER MODULE.
No sleep.

Disconnecting FH6 in the football and the car sleeps.


Next I disconnected the DSM and depinned the blue SCP wire from the REM, and the car went to sleep. I have plugged the seat back in and I'm on the 40 minute countdown ! Fingers crossed it's the seat module. I fitted the seats


from my old car, but everything functions as it should.

 

Well? The suspense is killing me...

 

Yes, it is a tracker put in by the dealer. Palm Beach Jag in Miami put it in mine brand new. If your car goes missing, you give the LoJack number to the cops. Takes about 30 seconds to find your car as per the brochure. I don't know about current draw but it is armed 24/7.