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It's not clear what this is measuring. It appears to be 85 microamps, but it's uncertain whether that is large or small (or neither) depending on the measurement.
Hi CR
I discovered a Parasitic Battery Drain which took my battery down to zero over the course of a couple of days. Trying to isolate it,,, I turned off everything. Waited for the systems to shut down and put the DMM in line, connecting one probe to neg battery terminal and the other to the chassis
Oops,,, hit reply by accident
~~~ ground... This is what was measured. So, that's less than one amp,,, or much much less than an amp...? A good result you think?
I presume you have the Digital Multi Meter in series with the battery, measuring a current draw of 85mA with the car off and asleep.
That should be fine normally, but right now you've all the ancillaries pulled out. If one system, eg Music Amp, HVAC or cigar lighter, is pulling current when the car is off, that's what you need to find.
Thank you...
Yes, right. That it's within limits is good to hear... I will go and one by one reconnect these units,,, and see what I have. I was really just uncertain that what I was looking at was what I thought... Thanks for telling...
I have a ton more work to do on this thing, lol
Really struggling to figure out my fueling issue...
I posted some findings in another thread dealing only with the fueling problem and the FPM not sending a pulse signal to the pump...
I presume you have the Digital Multi Meter in series with the battery, measuring a current draw of 85mA with the car off and asleep.
That should be fine normally, but right now you've all the ancillaries pulled out. If one system, eg Music Amp, HVAC or cigar lighter, is pulling current when the car is off, that's what you need to find.
I could be mistaken, but looks like he has the 2 milliamp scale selected and the result is in milliamps (upper right of the display). So, very small current (85 microamps) in the context of battery draw?
I could be mistaken, but looks like he has the 2 milliamp scale selected and the result is in milliamps (upper right of the display). So, very small current (85 microamps) in the context of battery draw?
Haha,,, that's why I'm here... I know that you weren't directing the question at me necessarily,,, but yeah,,, I don't trust my interpretation of the reading.
I plugged in the new head unit, stereo and HVAC etc (have an Err message I can't get rid of),,, and will retest tomorrow... Push out some more tranny fluid and keep poking around at things. For the most part I am happy with how things are moving along...
I only have xk8 headlights and I am going to try my hand at splicing in some xk8 plugs ingot on eBay and,,, let there be light ~~~ God willing, lol
Hi CR
I discovered a Parasitic Battery Drain which took my battery down to zero over the course of a couple of days. Trying to isolate it,,, I turned off everything. Waited for the systems to shut down and put the DMM in line, connecting one probe to neg battery terminal and the other to the chassis
Oops,,, hit reply by accident
~~~ ground... This is what was measured. So, that's less than one amp,,, or much much less than an amp...? A good result you think?
So, negative terminal (with regular negative lead connected, I assume) to chassis (ground)? Even though this appears to be a small current, I'm a bit surprised it is not smaller. You are essentially indirectly measuring how far off chassis ground the negative terminal is. Another way to do this is to check the voltage between the connected negative terminal and the chassis. It should be very close to zero. If it's not, check all of your grounds.
If you're looking for quiescent current draw, then I'd disconnect the cable from the negative terminal and use the DMM as an ammeter, like you have done here, between the negative battery terminal and the disconnected negative terminal cable.
So, negative terminal (with regular negative lead connected, I assume) to chassis (ground)? .
If I'm understanding your question right ~~~ Umm, no, I disconnected the negative chassis ground at the battery. Clipped the POS DMM lead to the battery terminal and the other clipped to the ground strap to the chassis... Let sit a while and this is where it settled...
If I'm understanding your question right ~~~ Umm, no, I disconnected the negative chassis ground at the battery. Clipped the POS DMM lead to the battery terminal and the other clipped to the ground strap to the chassis... Let sit a while and this is where it settled...
Thanks, I see. So, based on what your DMM appears be saying, that's a minuscule current. Typical values are somewhere in the 20-30 mA range, I think, with everything connected and the system quiescent. I'd put the DMM on the 200 mA range. Set on that range, your reading would essentially be 0.1 mA.
Just as an aside which you probably know already, if you try to crank the car with the DMM on that setting (or any of the settings) and in that configuration, you may trip fuses or break it, depending on the meter.
Thanks, I see. So, based on what your DMM appears be saying, that's a minuscule current. Typical values are somewhere in the 20-30 mA range, I think, with everything connected and the system quiescent. I'd put the DMM on the 200 mA range. Set on that range, your reading would essentially be 0.1 mA.
Just as an aside which you probably know already, if you try to crank the car with the DMM on that setting (or any of the settings) and in that configuration, you may trip fuses or break it, depending on the meter.
Haha,,, I did know that. Learned it from that Eric the Car Guy on a YouTube video...
Ok... So, tomorrow, I will do as you say, plug everything back in and see what I get. I suspect it will be higher... Hopefully just a bit. I am thinking that maybe, just maybe, my key latch didn't fall closed, which killed the battery... This car is full of ghosts...
If you have some time I would love to have your thoughts on the NOT FUELING thread... Got some completely unexpected and confusing results today reading at each of the sensors, modules and connection points... I think,,,, all normal. Still no PWModulation at the pump. CrazyMaker...
Recheck this AM with everything plugged back in,,, 20mA setting... Less than one amp,,, steady... Imma hit my key slot with a drop of WD-40... Maybe it just got hung up in the open position? Or, maybe it was that submersible head, ac and stereo unit. OMG...
I had a parasitic drain in my XJS. It's my passenger side blower motor. I found out for certain by hooking up like you did and pulling fuses one by one. I had .058 draw with the door switch and trunk switch closed. It was enough to drain my battery within a couple of days. As soon as I pulled the fuse for the passenger side blower motor it dropped to zero! Zero draw is better than any draw lol 😁
I had a parasitic drain in my XJS. It's my passenger side blower motor. I found out for certain by hooking up like you did and pulling fuses one by one. I had .058 draw with the door switch and trunk switch closed. It was enough to drain my battery within a couple of days. As soon as I pulled the fuse for the passenger side blower motor it dropped to zero! Zero draw is better than any draw lol 😁
Sounds right. On my XJS I think I remember it being like .01 - .02,,, or something like that. Never had a battery problem there. Cept when driving, lol... Anyways, I think if I had ZERO on this hummmdinger of a Jag, or my xk8 ~~~~ something would be wrong... Welcome to Jag world... Jeeeeze Louise
The flood damage on the headlights was not repairable. Headlamps are hard to find and very expensive.
I have very little into this car and lots of things are coming together, coming back to life (with coaxing) and needless to say I am very relieved and excited...
I will not be heartbroken if I don't have leveling headlights. Maybe I'll get them someday...
I have a pair (2 actually) from xk8s of the same year, roughly. I went online and ordered pigtails from a wrecker for $20, found the wiring diagrams and matched up the wiring in a few minutes before getting to work on the weekend.
I have installed one, things worked out very well, but as usual I have a question or two:
I had left over wires. The xkr has 9 leads, the xk8 6... Looking at the diagram, I see that the XKR has a system of light leveling... WR and W on both L and R plug ends. The XK8 does not have these... Should I expect a message on my dash if I DON'T connect these wires to something??? An error? To prevent a message,,, what could I do??? What resistance(or) would mimic the power pulled by the leveling module if out in series???
Also,,, as I found, it is 9 leads on the XKR and 6 leads on the xk8 light... I still have one left (W) and I'm not seeing it in the diagrams. I will take another look. In my experimenting this weekend,,, once connected,,, I did not get that little pen light (the one I like so much) up in the top upper and inner corner of the headlight unit to light. I wanted to place a dark blue LED in place of the white/yellow bulb... In y'all's xkr experience, is that 9th lead for that little bulb OR,,,, what is it, lol? CrazyMaker, this thing is... Maybe the lights are just blown or there is something else going on.
Got back into things a bit today. Directly wired pins 25 and 27 to terminals 3 and 4 (red dots in photo) from the ecm to the fuel pump module. No change - No joy. As I've been working on this, to run the car, I've had to hot wire the fuel pump - grounding it only - where it then runs full blast. I can tell that the fuel pump doesn't like it.
If anyone would like to scratch their heads with me on this I am more than willing to share electrical diagrams upon request, lol
After having a new key made by Jaguar, car will start with key turn, which is nice, but still, the fueling is a PITA.
I was thinking (always spells troubles, money - or both) that the linear switch in the JGate is all tied into the CAN system (which I understand very little about) so I ordered a new used one from "AutoReserve" in the UK. See if that solves anything. Maybe the signals to tell the BPM and ECM that the car is ready and safe to start is sending mis or bad signals in the linear switch and ok's for crank but NOT for fuel? There is a LOT going on across systems for start up.
Only DT codes are for high output for the fuel pressure sender/regulator (fuel pressure is high) thingy on the rail and an O2 sensor heater on bank 2... Lol, looking forward to a simple O2 sensor change - all things considered.
I simply cannot figure out what's going on with the pwm for the fuel pump. It's really getting to be a drag. Had it at a garage here on Staten Island. A guy who says he "is a Jag expert and has alllllll the diagnostic equipment to figure out anything"... Did nothing for my issue. I don't even wanna report what I paid him. I don't like going to mechanics. Even more now than before.
Anyways. Slowly but surely.
Still determined. Screen shots get blurry. Sorry.
Easy bit first - the high fuel pressure code is a good thing in one sense as it tells you that part of the fuellling system is working. As you say, the pump won't be too happy running continouously at full bore.
Point-to-point wiring direct between the FPM and ECM should eliminate any circuit breaks. Can you still read voltages on these two wires? Why in a group of 6 did Jaguar choose to have two the same colour (rhetorical question)?
I think you now have the correct pump for the 4.2?
Easy bit first - the high fuel pressure code is a good thing in one sense as it tells you that part of the fuellling system is working. As you say, the pump won't be too happy running continouously at full bore.
Point-to-point wiring direct between the FPM and ECM should eliminate any circuit breaks. Can you still read voltages on these two wires? Why in a group of 6 did Jaguar choose to have two the same colour (rhetorical question)?
I think you now have the correct pump for the 4.2?
Good Morning Michael! You are a great supporter to have read all of my messy and sidewinding posts. Thank you! I just reread myself, what a painful thing, lol. If it was bad for me, I can't imagine what it's like for y'all. Jeeeesh!
I agree. Being able to read live pressures and getting a code for high pressure IS a good thing. It's reporting to the ECM, thankfully.
I did end up getting the correct VDO pump way back when... Just the pump, for a small amount of money compared to what a new set up costs. They are hard to find, just pump without all the plastic.
And yes, lol, two same colored wires... Back to front.
Believe it or not, when I removed the center arm rest console the first time (way back when) it was only these two white wires that had seen mice TEETH (different taste?)! I replaced both segments of wire with small self soldering connectors and never looked back. Then, as you can see in the photo, the FPM in the boot had experienced significant heat and it was toast. I have replaced it (I have 3 known good modules now, lol) OMG.
If the FPCM module looks like this could it have stressed the hell out of the related circuits in the ECM, I thought, so bit the bullet last night and thankfully found an ECM and it's in the mail now. Donor is 3 months difference in manufacture dates between the vehicles.
I have not made any complete/permanent cuts in those white wires between the ECM and the FPCM. Heated and skinned a small section of wire at the back and front, twisted in splice, and ran the wire outside the car. No luck. I'm wondering if that (OE wiring STILL connected) may have caused an issue with juice getting to the FPCM correctly.
For voltage at the wires. One, I don't really know what I'm looking for. I didn't take a measure as I couldn't find my damn DMM. I will be trying to at least see if I can get a range of voltage and IF my DMM has a frequency/duty cycle % function.
The fueling is my only real and MAJOR issue at this point. Then, 100 little-er things.
Still, I'm liking this.
This is the old FPCM. May have fried or over stressed related circuits to ECM? Who knows...
Last edited by JayJagJay; Mar 4, 2021 at 06:03 AM.
If the FPCM module looks like this could it have stressed the hell out of the related circuits in the ECM, I thought, so bit the bullet last night and thankfully found an ECM and it's in the mail now. Donor is 3 months difference in manufacture dates between the vehicles.
Given you have a replacement, I'd toss the original FPM into the parts museum.
There aren't too many actors left in this conspiracy, so another ECM should help narrow things down further. Be aware that it may need programming as it's tied into the security system (talks to the KTM).
Originally Posted by JayJagJay
Believe it or not, when I removed the center arm rest console the first time (way back when) it was only these two white wires that had seen mice TEETH (different taste?)! I replaced both segments of wire with small self soldering connectors and never looked back.
You did definitely not get them crossed?
Originally Posted by JayJagJay
For voltage at the wires. One, I don't really know what I'm looking for. I didn't take a measure as I couldn't find my damn DMM. I will be trying to at least see if I can get a range of voltage and IF my DMM has a frequency/duty cycle % function.
I'm asking in case there is a short to ground/B+ on either of them, although you reported getting a DMM response on each of the two wires in a previous post. You should be able to determine some information on the 150Hz from the ECM if the DMM reports RMS values. The 1Hz 'heartbeat' is more tricky as it's a very low repetition rate:- not too easy to see on a scope either (or at least the ones I've used in the past).
