I've been working on a fuel pump issue and noticed a small 1.5 inch electrical component attached to my fuel line as the line crosses over the top of the tank. There are wires plugged into the connector, anyone know what this thing is?

 

Pictures

 

level sensor?

detonator?

 

sorry a pic is attached... notice it is connected to the fuel line. It is up under the sheet metal and nearer the drivers side tank. Can't tell where the wires come from, can barely touch the plug.

 

Thats not a fuel line but a vent line, and that looks like the vent solenoid

 

ok, I'll buy that. Looks like the fuel line on the other side of the tank. Oh I miss when cars were simple and easy to work on...

Thanks Brutal....

PS. do you know if there should be ground and power to the fuel pump when the ignition is turned off? Mine seems to be that way. Tomorrow a friend is bringing over a scope and we will investigate. I don't want another dead pump.

 

The pump is driven PWM (Pulse Width Modulation). I don't think you can check it properly with just power and ground? It's not like older cars and pumps. See this from the JTIS below;


The electronic returnless fuel system utilized has the following advantages: reduced fuel tank vapor. requires less electrical power, does not require a fuel return line. The intelligence of this system is contained within the engine control module (ECM). The ECM determines the required fuel flow and communicates this information to the rear electronic module (REM). The REM has the fuel pump driver functions fully integrated into the microprocessor. The fuel pump relay is activated by the ECM power relay and provides a fused power supply to the REM. The ECM and the REM calculates the frequency and determines the current required by the fuel pump to maintain the correct fuel pressure at the fuel injectors. The fuel tank is of a saddle design which incorporates a pump/sender unit in both sides of the tank on vehicles with superchargers. On vehicles without superchargers, the right-hand side houses the fuel pump module and the left-hand side houses the fuel transfer pump. The fuel pump cross over lines are internal to the fuel tank to reduce potential leak paths. Fuel is supplied at high pressure to the injectors via a fuel rail which incorporates a fuel pressure and a fuel temperature sensor. The ECM increases the fuel pressure to minimise fuel vapor formation to maintain fuel flow across the injectors. An inertia type fuel shutoff switch will cut power to the fuel pump in the event of an accident.
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I've read a good amount about PWM dc motors in the last few days and while it is true the circuit can't be tested like in days of old nothing I found says the current and ground is always present in some form. I talked with an electrical engineer friend about it and while he is not an automotive systems guy he thought it would be very odd to have situation I have. So tomorrow he is coming over with test equipment/ scope and seeing exactly what is being passed to the pump.

I have talked about this current issue in more detail on a fuel pump thread, best not for me to get confused posting in two areas.

Thank you for the JTIS info.

 

you can scope PWM, or you can dvom and look at the bar scale on the bottom of the screen. Itll show minor electrical movements that you cant read in digital. But what are trying to check? the ecu turns on the pump everytime you turn the key on and supplies 1 sec battery voltage

 

I'm trying to tell if what my digital volt meter says makes any sense. Connecting to the 2 wires from the recm that drive the pump (not the rheostat) I get 11 volts solid with the key turned off, turning the key on has no spike on the meter. So, based on several peoples comments that only a scope could show what is really happening I will connect one up and see what the pump is getting from the recm. A pump failing after 3 months and 2000 miles is very odd so I'm trying to be sure there is not something which caused the failure. I suspect any continuous current to the pump, even low current, would in time cause pump failure. At $600 for a Jaguar pump I sure don't want another burnout. Guess it is also possible the engine ecm or recm has gone bad which people say is very rare but things happen. I've looked for a used recm for my 05, very few around, and none with numbers like mine so I would need to get mine rebuilt. Not sure I trust that approach since those things are damn complicated. Since the ecm sends the signals to the recm (from what I have read) it might also be the problem.
I also switched around relays when I first noticed the current on the line but that did not change things.

Any ideas are surely appreciated.

 

The ECM does send it, and I believe it's also PWM. I don't know if the two signals (in & out of RECM) should look alike.

I don't recall any other posts about this, You're a pioneer!
(apart from the jag techs)

 

Understand you are getting too deep into this without the proper scanner. The JTIS shows dozens of error codes just in this area. Most are not at the level you can read with aftermarket test equipment. Consider you might need to have a factory tech look at it in some detail. You need someone who is knowledgeable on Jaguar's not PWM operations.
Like Brutal said even after you scope it what will it tell you?

I have attached a 10 page document on fuel pump trouble shooting. You can at least do some things but please get the JTIS! It's only $10 on EBay.
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I had another independent shop here in North Tx call me about a 2003 S-Type V6 about 3 pumps failing in a short time (several weeks??) I told them it has a PWM signal returnless system and just throwing pumps after pump is not going to fix it. I sent them some factory electrical guides and the 2003 S-Type update booklet but I never heard back. I remember when I was at the dealer another guy had the same situation. but the system would go 'full rich' and set rich codes so it was easier to diagnose. It turned out to be a faulty REM running the pump full power. The ECM was sending the correct PWM signal but the REM would send full 12V power every once in a while.

The little transducer on the tank top is probably the FTP sensor (fuel tank pressure sensor). It is in the upper right hand section of the Electrical Guide 2005 S-Type engine management V6 figure 03.1. There is an asterisk by the part to denote that the CCV and FTP sensor are only on the NAS.

Your car is North American Spec.

NOTES:
* EVAP Canister Close Valve and
Fuel Tank Pressure Sensor - NAS
vehicles only.

bob gauff

 

Clubairth1
thank you very much for the info. I should get the JTIS for the 2004 even though I have a 2005 and things in this area are different. I'm sure most systems are identical. I have the 2004 wiring schematic and color codes don't match with my 05 so it can get misleading. Even during the 05 run Jag changed some fuel system things and getting parts is confusing. The vin indicates one type of pump but that is not what is in the car, it is the other. A Jag dealer (out of state) said that is typical.
I was told by Jagv8 that after 04 info is on Topix only,which kind of sucks for the car owner. I may try and register on Topix anyway.

I imagine most people feel I should just get the car to a Jag dealer but my dealer is not that good on normal things and for something like this I don't want to be paying for their experimenting. My being unemployed doesn't help either.
I did have the recent failed pump installed at a shop, it is an actual OE pump, and will be covered under warranty (1 time). But that doesn't help with the towing charges and the fact my wife was driving the car both times a pump failed. She loves the car but feels she can't depend on it and unless we know exactly why the pumps failed she is not going to drive it.

So either I find out exactly what happened or just replace the pump and trade the car in. Very tough times...

 

Thank you Motorcarman, now I have some reading for the night..LOL

We connected up scope and my friend explained a lot of things to me about pwm. I now know the pump unit always has power to it but very very little current until recm sends it, it seems the pump has intelligence in it to respond recm and switch fuel flow between tanks to keep the fuel level balanced.

These control signals are carried on the voltage lines at a very low level. I could see the signal come through when the ignition is turned on. There was no increase in voltage itself but if I had a good pump I expect the signal would have activate the pump motorand the draw would have jumped up.
There are other signals /control being passed along all the time what they are I am not sure but it doesn't really matter.

It does worry me the possibility of an rem going flakey and burning out a pump. I guess only time will tell.

New pump should arrive this week, I'll post update when I get it in..

Thanks to everyone who have provided me with such good information and much needed help.

 

Pump in and working. Had some rough running when the car first started up but it has smoothed out now. The engine light came on, had two codes P2118 and P1111. I cleared them both and will see if anything comes back. With all the messing around I did I was surprised I only got those two codes. lol. Hope this pump last for the life of the car...
PS. I ordered a 2004 JTIS disk off of ebay and a code reader scanner

Thanks to everyone for the help, insight, info, and patience during this terrible time.

 

Hooray!

P1111 is normal (means OBD monitors ran OK). You'll have P1000 until it converts to P1111. If it doesn't, post back!