My 2002 S type Jag shows all the symptoms of being out of gas when it has a full tank. The shreader valve shows no pressure. I suspect it's a fuel pump. Where are the relay(s) and/or fuses for the fuel pump? Are there any other tests I can do to find out what the problem is before I dig into the fuel pump? Thank you

 

Easiest test would be to have someone listen on the rear passenger side when you turn the ignition on (don't start engine) listen for a 2 second woosh sound.

If you hear nothing odds are your fuel pump is kaput.

Next would be to ensure you have at least 10.5V at the fuel pump with key on. If you do you can scratch off relays, fuses or inertia switch.

 

Wiring diagrams here:

http://jagrepair.com/images/AutoRepa...x2032002en.pdf


See section 3.2 for the V8, or 3.4 for the V6.

You can do much of your troubleshooting from relay R7 at the rear power distribution box.

1) Unplug R7 and check for 12VDC at socket #3. This is unswitched battery power. If no voltage, check fuse F17 in the rear power distribution box.

2) Check for power at relay socket #1. With the ignition off, you should see nothing. Turn the key to ON and you should now see 12VDC. If not, check and reset the inertia switch. If still no voltage, check fuse F4 at the primary junction box. This is at the outboard side of the US passenger footwell.

3) If power checks good at both locations, try swapping that relay with a known-good relay from another location. I think the fog lamp relay (R7 at the front power distribution box) is the same. Try the fog lamps to confirm that relay is good, and then swap the two to see if the fault follows.

4) If still no joy, access the two wires between the rear electronics module and the pump. I'm not sure which connection is easiest to access, whether at the module, the pump itself, or that connector in the middle. Whichever you use, you can check continuity through the pump. If open, the pump is bad.

 

Welcome to the forum Steve,

I've deleted your duplicate post of this same question.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Hello Karl





kr98664 ... thank you for your help. I'm still not getting her to start.
I'll be as accurate as I can and let you know my steps.
Step 1 .. I removed Relay # 7 in the boot and checked for voltage. 12 volts is there even with the key off.
Fuse 17 was blown but I replaced it last week and the new one is still good.
Step 2....Forgive me is I don't understand some of the terms or language here but I presume when you say 'relay socket #1 you're talking
removing the relay #1 in the boot marked 'switched system power relay'. I got no voltage with the key off and 12 volts with it on.
Step 3....I swapped, checked, verified relays R7 in the boot with the one for the fog lights. Both check good.
Step 4....This is where I lost you. I have the back seat out so I can access the connections to the fuel pump on the passenger side and the sending unit on the drivers side ( USA) Sorry but what are you calling 'the rear electronics module'? Do you mean the box with
all the fuses and relays? Should I disconnect the connector at the fuel pump and check for continuity on the wires going
into the pump. the wires leading to the fuel pump? Am I in the wrong place? All this with the key off? On?
There are only two more things that I can possibly think of; as I said in another post, my bad...I didn't put in new mesh fuel filters on the fuel pump or sending unit only because the new pump motor kit I ordered had two filters but they didn't work on my pump and sending unit.

The other thing is someone said something about a crank position sensor and I believe it's under the car on or near the engine? Is that right? But before I go jacking up my car and putting it on blocks and crawling underneath, removing it and buying a new one, would that have anything to do with the fuel rail not getting any gas and getting under pressure?
One last thing; the inertia switch. I'm not crystal clear where that is but below the trunk latch button and the gas tank flap, there are two micro switches. They just don't look like factory equipment but it's logical that the red on would be the inertia switch. Is the red button the inertia switch?

 

You're going to have to brush up on your mind-reading skills.

What I meant is where each relay plugs into the power distribution box, there are 5 sockets (or receptacles) where the 5 relay tabs fit. Each of those 5 sockets has a number for identification. To make it confusing, the ID numbers are on the relay itself, but not the socket in the power distribution box. You have to look at the tiny numbers on the base of the relay (next to each tab) and transpose them to the 5 sockets where the relay plugs in.

Make any sense? So for this question, I was still talking about relay R7, but now check for power at socket #1.

This is the ignition-switched power to operate relay R7, which routes unswitched battery power to the fuel pump. It's very important to check for power here at relay R7, socket #1. From my earlier message:

"With the ignition off, you should see nothing. Turn the key to ON and you should now see 12VDC. If not, check and reset the inertia switch. If still no voltage, check fuse F4 at the primary junction box. This is at the outboard side of the US passenger footwell."


I have NO idea what those two little switches are beneath your fuel door and trunk switches. Those are definitely add-ons, not factory.

To access the inertia switch, open the (US) driver's door. On the door opening near the upper hinge, you will see a flat rubber plug about 3" in diameter. Remove that cover to see the inertia switch. In a collision, that switch trips and shuts off the fuel pump by taking away power from socket #1 at relay R7. There's a reset button on the inertia switch to restore power.


Time for dinner, more details later...

 

More details of how the individual sockets are labeled for each relay. This picture, from my HVAC guide, is for the relay to the AC compressor clutch, but the general principles are the same:







The schematic on the left shows an electrical view of the five contacts for each relay.

Between contacts #1 and #2, that's the electromagnet that operates the relay. When energized (power at #1, ground at #2), the electromagnet pulls down the spring-loaded moveable piece that connects contacts #3 and #5. When the electromagnet is not powered, that spring-loaded piece relaxes and breaks the connection between #3 and #5. Remember, a relay is a device that lets a low-current circuit (the electromagnet) control a high-current circuit.

The view on the right shows how the five contacts are physically arranged where the relay is plugged in. This is an overhead view looking where the relay has been removed.

 

The Rear Electronics Control Module (RECM) is a computer box thingy in the right side of the trunk. I've never had to mess with mine, so don't know the exact location. If it's like the other control modules, it's probably about the size of a Tom Clancy paperback, with several big electrical connectors on one edge. This module controls many functions, such as the fuel pump, fuel quantity, rear exterior lights, rear defroster, etc.

If you happened to be staring at the RECM, it's a great place to check the continuity of the fuel pump itself and the wiring between the two. If not handy, go with wherever you have the best access.

You mentioned already having access to the pump wiring underneath the seat, so I'd go with that. Disconnect the plug for the pump. Turn the ignition off, as you're not checking power to the pump, only continuity through the pump and associated wiring.

Set your meter to ohms and touch the two leads together. You should see very close to zero ohms, possibly a fraction. This is just to test the integrity of the test leads and the accuracy of the meter. Now touch the two leads to the two contacts leading to the fuel pump. This is now measuring the continuity of the pump. I don't know the exact value, but several ohms sounds about right. If you see zero ohms, or close to it, the pump is shorted internally. If you see infinite ohms, or some very high number, that means the circuit inside the pump is broken. Let us know what value you get. Hopefully somebody can chime in with what range is normal. Basically you shouldn't see a direct short (zero ohms, or close to it) or an open circuit (infinite or very high ohms). Edit: I should clarify this resistance test can NOT conclusively prove the pump is good. It's more of a test to weed out one that is blatantly bad.

The next step is something I haven't covered before, but it's a quick and dirty test of the pump. You've got to promise me you will do it EXACTLY as I will describe for maximum safety. Please run through the previous steps 1-4 first, just to check power, inertia switch good, etc. You had already swapped the fuel pump relay R7 with the one for the fog lamps, so we know that relay is good, too.

Leave the connector disconnected after the resistance checks you just did. We're going to skip the rest of the pump control circuit and momentarily apply 12VDC directly to the pump connector and see if the pump runs. But don't just rig up a pair of jumpers and start throwing power around. It's VERY important to have a fuse in your test circuit. We're going to use an existing fuse that feeds that pesky relay R7.

Pick up a set of test jumpers with alligator clips at each end. At the fuel pump connector, pick one of the wires and connect it with a jumper to a good ground. I don't know if the pump is polarity sensitive (many are not), so just pick one wire to try as ground. If that doesn't work, we can swap leads later and try again, but don't worry about that for now.

For the other pump wire, you will need to run a LONG test jumper back to the rear power distribution box in the trunk. You can fabricate a simple jumper by adding small alligator clips to a long piece of wire. Or if you have a pair of premade jumpers with clips at each end, you can put a long stretch of plain wire between the two and end up with the equivalent of one long jumper. Wrap tape around the clips in the middle so they don't accidentally short to ground.

With your new long jumper, connect one end to the remaining wire going to the fuel pump. At the far end, back in the trunk, remove relay R7. Unfold a paper clip or fabricate something similar to reach into socket #3 for relay R7. This is unswitched battery power, protected by fuse F17 in the rear power distribution box.

When you make contact back there, the pump should run. With the engine off and the rear seat's bottom cushion removed, you should hear it. Only let it run for a few seconds and then disconnect the power. Go up front and check the Shraeder valve. If the pump is good and filter wasn't clogged, you should have pressure. That tells us the pump will run and the problem is on the control side.

If you don't hear the pump run, double check for power at that relay socket. Make sure the ground jumper connected at the pump is making a good connection, too. If all good, swap the two test jumpers at the pump connector to reverse the polarity and try again. If you try the polarity both ways and the pump still doesn't run, your $10 pump was no bargain...

This is VERY important: Always make or break the test connection back at the trunk. That way, in case there's a spark, it is well away from any potential fumes near the fuel pump.

 

Kr98664,

is this the same process for the 2000 S Type, but instead, checking relay#6 and fuse#__? I initially thought that it was my PATS killing my fuel injection, but the locksmith said that if my PATS LED isn’t flashing at all l, then most likely the PATS is not my issue.

 

I have NO idea what those two little switches are beneath your fuel door and trunk switches. Those are definitely add-ons, not factory.

 

Could this be toggles or a deadman/kill switch?

 

Could this be toggles or a deadman/kill switch?

 

Left front kick panel under the dash