I pulled all relays under the hood. 13 in all and tested them all. 12 work fine and have the correct resistance when activated. The 13th however was just a cover with no “guts.” I find that very curious as the wiring to that relay is substantially heavier than the majority of relays. It’s one of two relays on the right side inner fender near the windshield washer fluid. I’ve attached a pic to show the wiring. Perhaps someone can tell me what function this relay performs and can identity the wiring from the colors?



Pics of the “empty relay” and wiring that the relay would control if there was an actual relay under the shell

 

I found a grey



relay in drivers side rear seat kick panel that doesn’t appear to work when I tested it. I’ve enclosed a pic and from my research is related to heated seats so shouldn’t impact my No Crank problem.

 

Good job checking all those relays, power and ground points. Have you checked the engine block ground strap? Left side, low down below the starter.

The empty relay shell is there to cover the socket for the headlamp washer jet system, which is not installed on any USA market X300 cars as far as I know. So a relay is not necessary although the wiring is found in all cars. This applies to other optional equipment such as traction control, premium audio or heated windshield. The wiring is in place but not connected to anything.

The white stripe on top shows it is different from the others and not an actual relay.

You will want to check the two square connectors on the frame below the fake relay, a black one and white one. Called PI1 and PI61, they are multi-point connectors and are known to get wet, dirty and corroded and sometimes lose contact. The starting system is fed through these connectors.

Also test the 5 king relays in the 5 fusebox locations, if you haven't yet. Keep in mind that those 5 relays activate fuse locations 10, 12, 14, and 16 in each box, when the key is in the "run" position. Of course, some of those fuse locations will be empty and some are used for important things, which you can figure out with your fuse diagram under the lid in the engine compartment.

 

Are you talking about the connectors I have circled in red?

 

The connectors in the lower red circle near the sounder are the PI1 & 61 connectors. The upper red circle are 2 of the O2 sensor connectors. If you disconnect those O2 sensors, don't mix them up. They are assigned by the ECU to specific O2 sensors and the engine won't like it if they are swapped.

 

I haven’t attempted to separate the 02 connectors and probably won’t unless needed in the future. I attempted to separate Pl1 and 61 and they are not easy to separate. I left them soaking in PB Blaster last night hoping that will help.

Thanks again for the insights and encouragement.

i haven’t opened the console yet to access the two relays by the gear shift. I know at least one is clicking as I can hear it when the ignition is in position 2 and I press the foot brake.

I’m not sure if you saw the ECM pic I posted weeks ago that showed some corrosion. I’ll attach it here. It was just one pin that was green. I cleaned it and tried to inspect the inside of the ECM for more evidence of corrosion but didn’t see any. I found evidence of water residue on the BPM and other issues seemed to point to the BPM so I replaced it and it seemed to help with the other issues but not the no crank issue. I’m now wondering if my problem is the ECM as well and I need to replace that too. I understand the BPM is more generic than the ECM and the ECM numbers need to match exactly.

 

Contacts all look good
Are they any tests I can do with the contacts exposed?

 

Both LNA 6700 AA relays test ok

 

After extensive testing of relays, fuses and wiring connectors I still have the “no crank” condition when I turn the key to position 3. A friend asked me if it’s possible an “immobilizer” feature of the cars security system has been tripped. Can anyone tell me if Jaguar included this security feature and if so how to reset it. I see no evidence of an aftermarket security system. My friend suggested locking the door with the key and unlocking with the key before trying to start which I will try today. The car came with the original fobs all of which had dead batteries. I replaced all the batteries but none of the fobs work. I put this down to the BPM issues I had before changing out the BPM. I don’t believe I’ve tried the fobs since changing out the BPM but will try that today too. I read the post about resetting the fobs with the valet switch and will also try that if no response. Thanks in advance for any ideas and insights

 

I tried to lock the doors with the key and found turning the key doesn’t activate any of the electronic door locks. Is there a module that controls that function or is it a function of the BPM? I removed the drivers side door kick panel still hunting for electrical problems that maybe causing my “no crank” issue and found the pictured relay with obvious corrosion. Research suggests it’s for the power steering so perhaps unrelated to my no crank problem? I haven’t tested the relay but judging from the corrosion I’m guessing it bad. I’ve also included a pic of the PECUS sticker from the trunk.

PECUS sticker


LNA2100BB

 

No sign of any corrosion or water damage on contacts or board

 

USA cars have no immobilizer system except for full alarm state. No key transponders either.

The key used in the door lock closes a microswitch that will throw the door locks via the electric actuators in each door. That and the key fobs are a separate issue from the no crank situation. Did you program the fobs after replacing the batteries? It is a simple process found in the Stickies.

Try activating the starter by jumping the terminals at the starter relay (with the key off). Refer to the wire colors at the relay socket as follows.

First check the single white wire lead to the starter. There is a connector on this wire right above the starter and it should be visible in that area (at the rear of the intake manifold). Make sure that connector is good.

The starter relay is behind the left headlight, usually the innermost of the 4 relays in a row. It has 4 wires: brown/white, white/pink, white, and green/orange.

Brown/White: 12v at all times. Fed by fuse #3 in the LH engine bay fuse box.
White: This is the wire that carries the current to the starter to energize the solenoid.
White/Pink: 12v whenever the key is in the "run" position. Fed by fuse #12 in the RH engine bay fuse box.
Green/Orange: Ground when the key is turned to "start". Fed from the BPM via the rotary switch.

When you jump the Brown/White socket terminal with the White, the starter should crank. Be prepared for that and a little spark at the terminals.

If you do this with the key in the Run position, the engine "should" fire up and run.

If nothing happens, your starter solenoid is probably shot.

 

Thank you, all very helpful information. I’m guessing the micro switch in the drivers door has failed as the key doesn’t activate any other door locks. I will definitely try the process you describe and post the results. Thank you for the detailed step by step process.

 

After changing out the BPM most electronic functions came back to life except cranking in position lll. Long before changing the BPM and one of the first checks I made was disconnecting and cleaning the ground wire from the starter motor to the inner fender. I would have sworn I reconnected the ground wire but while checking wiring around the starter motor as advised by SleekJag12 I noticed it was not connected. As soon as I reconnected the ground wire the engine roared into life. I’ve learned a lot about the car during troubleshooting and will be forever grateful for all the advice and encouragement. Thanks to everyone who contributed, another cat is purring again.

 

That is good news, Chris! A happy ending (and beginning?). I think we've all had problems that seemed beyond logic until finally, one simple thing made all the difference. Cheers!

Time to go DRIVING and enjoy the music.

 

I was told the ‘97 started life in Chicago, it has significant corrosion issues. I purchased it as a parts car for the ‘96. I had hoped the CD changer would work so I could “enjoy the music” but so far no luck. Today I switched the trunk liners, got the truck lights and license plate lights fully operational on the ‘96 all with donor parts from the ‘97. They share the same trim code and started working on the center console and glove box area but had to call it a night. The ‘96 started life in AZ and is corrosion free with 40k less miles. Sure is nice to able to move the parts car around under its own power. 4000lbs is a lot to drag around. Thanks again for your help. Your troubleshooting instructions will be very helpful in the future and for many other members.

 

Hi Richard:

I have a 96 straight 6 that won't start and was reading your post about the starter relay above and went and tried jumping the one on my car and the motor started right up. I tested the relay on the work bench and it operates fine. The windshield wipers don't work either and that relay is on the same bank of relays, any idea what they have in common that might causing the no start issue when turning the key? Any idea's where to look next would be apricated.

 

The wipers and starter circuit have in common the body processor module

For you ZF transmission the BPM looks for agreement that certain conditions exist in the form of ground " seeking "

Once that happens the BPM will " provide " a ground to close the starter solinoid relay

One of the fuses for the BPM is in the trunk ( x ) and pass through the large connector above the fuel tank ( BT4 )

This BT4 connector is a pain to get reconnected being careful not to break the lock pins

There is a cutout in a layer of sheet metal not cut out perfectly holding up the connector halves from coming together

There is a hard reset of the BPM you can do on US models as the BPM is wired hot at all times

You might try a soft reset by removing the positive battery cable for 1 hour