1999 HSK, Petrol
I had been having issues with a "FAULTY FUEL SENDER" indication on the message center display accompanied by fuel needle plunging
to zero and low fuel indicator light being illuminated.
This only happened after a fill up, so full tank. It got good when fuel was below 3/4 tank and was correct to empty.
I assumed that it was a sender with a worn track at the top end, so I swapped in a fully tested, known good fuel pump and sender assembly.
This seemed to fix the issue straight away! The old sender indeed had bad sections on the track at the top end, and about the 3/4 mark.
Bench testing with ohm meter confirmed this.
Now, however, I am getting a "FUEL GAUGE FAULT" indication on the message center, along with the needle plunge and low fuel light indication.
When ignition is switched on, the gauge reads correctly. after starting, and idling a few seconds it faults out. I noticed that a few times when it stayed accurate
for a bit, that pressing the brake would fault it out (Bad earth somewhere?)
Plugged in Nano, and looked at fuel sender values. Got a 36 and this dropped to a 26 when brake was pressed.........And went as low as 8.
I cannot seem to find my guide to the Nano that indicates what these readings should be?
Comparing to my 2002, the fuel sender readings on it stay solid at 69 when I press brake....(It has less fuel, so I would expect different number)
Any hot tips as to where to start looking? I have confirmed earths under the bonnet are good, so I suppose it's under the dash next.
I've seen FUEL GAUGE FAULT come up on the dash before, accompanied by the fuel gauge dropping to zero and the low fuel warning light coming on. However, that was due to wear on the track at a certain point that coincided with the amount of fuel I normally keep in the car. As the car runs on Propane, the petrol is purely a get you home option so the fuel gauge very rarely moved resulting in the wear. Replacing the fuel pump module cured it. About the only other thing I did was give the plug to it a squirt of contact cleaner before plugging it in.
Changing when pressing the brake pedal would suggest, as you rightly say, a bad ground connection. Fuel gauge and brake lights don't share a supply so it can't be a fuse but on a LHD car, both the ABS ECU and the fuel pump/sender assembly go to E0559 ground point. Your task is now to find out where E0559 is.....
Thanks Gilbert!
Turns out that E0559 is the one on the wing next to the coolant expansion bottle.
Clean and tight, but wire brushed just in case.
Also checked C1289 the 20 pin plug on BECM. Clean and tight. Checked all the plugs on the front, since I was in there.
All looked good, so no moisture getting to the BECM.
So, as I had done the "Surgically cut flap" procedure for the fuel pump (I have only gravel surfaces to work on at
present.....Shop floor coming soon.) It only took a minute to remove sealant and access the pump (Luxury!)
I opened the flap, and checked the pump connection. Clean.
Next I took the old fuel pump and plugged it in to see if the old problem was still the same.
Yep! gauge read correctly and exhibited all the symptoms that I expected from a known worn out sender.
Plugged the "New" pump back in, and, with key in Pos II gauge reads full, as I would expect, as tank is full......
So, start engine and within 5-10 seconds needle sails down to empty and I get "Gauge Fault" message.
The pump and sender was very recently in my 02 and worked flawlessly. I suppose I could have damaged it in the transplant, but took great care not to.
Odd that it thinks Gauge is at fault when it seems to be a sender issue?
Further thoughts welcome!
I am going to take it for a drive today to get the tank down a bit and see what happens.
Probably because FUEL GAUGE SENDER UNIT FAULT is too long to fit in the massage centre.... For the average owner, they wouldn't know what the gauge sender is, all he'd know is the fuel gauge isn't working correctly.
Not sure if relevant but the brake light switch takes power from the single connector on the back of the BeCM, the one that you access from the rear footwell. The HEVAC backlighting is on the same feed so if the HEVAC dims when you put the brakes on, that is suspect. There's one caveat to that. It is like that on a GEMS and I was recently told that a Thor BeCM will work in a GEMS but not the other way round. I thought they weren't interchangeable but this came from Les at Classic Rides North Wales who supplies the aftermarket keys.
FUEL GAUGE FAULT appeared every now then on mine a few months back. Turns outs the alternator was just about to give up.
New alternator, not seen since..
With the old sender, it did indeed say "FUEL SENDER FAULT"
And, it was indeed faulty.
I had my run to bring down the fuel level, and no change,
So, I went to the boat and got my good ohm meter......
I found the "New" sender reading 39 ohms.
So, got my trusty resistor substitution wheel, and clipped it to the sender wires.
For the resistance I applied to the wires at the fuel tank plug, I got these results:
47 ohms- Full
100 ohms- 1/2
150 ohms- 3/8
220 ohms 1/8
330 ohms- Empty
This is correct according to an old post on the dark side by Marty, so you know its good data!
Looking like the sender got upset during it's transplant.
Next, I will obviously need to pull it back out to see what I did to upset it!
On the subject of BECM compatibility, At least for NAS spec, they seem to be reverse compatible.
Long ago, I had Scotty (Remember him!?) unlock and clone one from my 95 parts car to work in my 02, which it has been doing just fine......
Not sure, but he may have done a firmware update as well????
Thanks, once again for the help!
I will report back when I find out how I managed to destroy a perfectly good sender.
Right!
So, I have tested 2 different, but used sending units and they both have a few issues.
Mostly, the fuel gauge reads mid and lower fine, but as soon as they go above about 4/5 tank, the
fuel gauge plunges to empty, the range light comes on, and "Fuel Gauge Fault" is announced in the message centre.
Just put in a brand new genuine Bosch pump after first checking sender with ohm meter and plugging in the unit
whilst still outside of the tank (unplugged fuel pump to prevent dry running) and gauge read just fine until I ran it to the full side of the sender, then, same result. Straight to empty.
I understand that if you run the wiper off of the PCB traces, it will show a fault, so that should not be the problem.
Installed, and with about 4/5 tank of fuel, when you switch on ignition, it reads correctly for a few seconds, then goes to fault mode.
I would suspect corroded plug, or wire issue if it had not passed with flying colours when I used a resistor substitution wheel and the gauge ran in a very linear manner.
Is there a calibration on the cluster for this, or possibly, I do have a corroded wire somewhere. I have not cut out and re soldered the kick panel plugs, but will have a look there next.
Aside from that, I am out of ideas.
Not really a problem as such, as it reads very well down to empty, which is the important bit, it is just annoying that I cannot solve it!
Upon further investigation, I found the RH kick panel plugs to be SERIOUSLY green.......
Whipped out the soldering tools and heat shrink, and fixed them. While it did not seem to effect the fuel gauge issue, it did fix the LH rear speaker and the subwoofer.
(Being the Missus' car, I was not really aware they were out....) Glad the soldering job fixed something!
Fuel gauge is mostly working, but I do not think it is calibrated correctly.as in resistance being added by a bad connection.
Also, discovered a mystery black wire coming out of the loom under the door sill cover that had a 1/4 inch ring terminal on it.
The matching red wire with it,went to a 5 amp fuse that looked a bit aftermarket but well done and seemed part of the harness.
I had a suspicion that this was possibly power and earth for the Phillips Incar nav system that has never come on, so I
Jumped black wire to earth, and lo and behold! The sat nav worked.....sort of.
It would load the dvd, but not recognise it.
As I had a spare Dvd drive, I swapped it in and now have a fully functioning, virtually obsolete GPS nav system!
I had been intending to fix this thing for a while, so glad it was an easy fix!
I am guessing the sender wiring goes through the LH side, and hope to find cruddy plugs there as well.
Looking at the ETM, the fuel gauge wire (Green/Black) goes directly from BeCM to gauge sender with no connections between. ETM also says that the resistance should be 19 Ohms when full, at 175 Ohms it brings on the low fuel warning light and when empty it is at 270 Ohms. There is an adjustment in the cluster (a small trimmer pot) so you could substitute a resistor for the sender and make sure the gauge reads what it should at set resistances.
Thanks, that's actually the next step.
I'm rummaging around the shed looking for the box of pots to do just that.
Thanks for the numbers!
It's possible the PO or his "expert" shop have screwed around with the calibration.
Got a message center bulb to replace anyway so I will have a play with it.
I guess just fill it up and adjust as appropriate.
There's 3 trimmer pots on each side along the top of the instrument cluster main pcb (unclip the translucent cover to get to them). On one side they deal with tacho and fuel gauge readings while the other side deals with speedo and fuel gauge. VR2 deals with the Temp gauge reading.
If you have a look here https://rangerovers.pub/topic/898-calibrated-speedos (post #6) I detailed how to get your speedo and tacho reading absolutely spot on if you have the patience......
Ahhh, thanks.
I recall that thread.
I will have a play with it this morning.
Also need to get rid of the annoying 5mph error on my 02.
Cheers!
Enjoy your holidays!!
What holiday? Set off Sunday evening, ferry to France, drove to just the other side of Amsterdam was there for 6 hours then drove back to Calais for an overnight stop, ferry this morning and now back home......
Well, you mentioned that you were answering questions from Calais.....
I shall officially amend my salutation to "Hope you enjoy(ed) your Banzi run
In the Plod...."
Arrrggggghhhh!!!!!!
I made up a cheater plug for the top of the fuel pump so that I can drive whilst substituting in various fixed resistors
feeding the resistance directly to the BECM via the pump plug.
I needed to do this as there is something changing on a dynamic basis while driving.
What I have observed so far is that with 150 ohms in, it reads about 1/8 tank. No fuel range light yet..
Drive a bit, and it will quickly twitch up 1/4 tank and stay stable there. No correlation between lights on/ off brake pump running / off.
When I switched in 67 ohms, it read just above 1/2 and was fine until, while driving, it went up the 1/4 tank increment.
No wonder that when it is actually full, the gauge freaks out for the first 1/4 tank as it is seeing the signal as out of range.
The resistance is not changing, yet the gauge is?????
So, as this is a signal that is being sent to the cluster as a digital stream, would I possibly be correct in pointing to the Becm as the possible
culprit?. I realise it gets blamed for many things and is rarely at fault however as the PO had their shop remove the Becm and send it to Turners
at at least one point, I am guessing someone messed around in there.
I have a spare board for the Becm that is allegedly a clone of the original, or is perhaps the original..
This is getting ridiculous to the point of being fun now!
Edit: The bad news is that the board I have is a power board.....The good news is that it looks to be in very good condition......No help for this one however.
Guess I will get inside the box and have a look for corrosion, etc.