My 04 Jaguar X-Type is cranking but not starting. I’ve checked the spark plugs and they not sparking, so I replaced them and the coils. Ive checked fuses and replaced them. I’ve come to the conclusion that I might need to replace wiring harness and/or the ECM. If someone could give me a diagram of the wiring harness so I could know where all connectors go when I replace the old ones that helpful, also if you have any other suggestions I’ll take those too. Thanks you

i know I could just replace the old harness with the new at the same time. But I would like to know all the names and locations of the connectors before I start

 

It is also possible, that nothing is/was wrong with your X.
Do you know the fuel cut off switch?



There is a metal ball inside, which jumps out of position (hence disconnecting an electrical connection), if triggered.
The fuel cut-off switch (also known as the inertia switch) on a Jaguar X-Type is typically located in the passenger footwell, behind a small trim panel on the right-hand side of the vehicle, near the front door post. However - I am not sure about that - if you do not find it there, check the driver's side (it may differ between LHD and RHD.

While it normally cuts off fuel only after an accident (or after you hit the kerb harshly), it apparently may in some models also inhibit sparks on the spark plugs...:The fuel cut-off switch (inertia switch) in a Jaguar X-Type primarily stops fuel delivery to the engine by de-energizing the fuel pump. It does not directly prevent spark plug sparks.

However, in some models, the switch is integrated with the Supplemental Restraint System (SRS), and when triggered, it can signal the Engine Control Module (ECM) to disable both the fuel pump and ignition system, which may include interrupting spark to prevent fire hazards after a collision.

So while the switch itself only cuts fuel, its interaction with the vehicle's electronics can indirectly prevent spark plugs from firing by disabling the ignition system. This is a safety feature, not a direct function of the switch.

Just press it to reactivate it....

 

I’ve tried to reset the inertia switch, but nothing changed. Maybe I should replace the switch altogether???

 

Unlikely that that inertia switch is faulty. But check the wiring to the inertia switch.
It's actually more likely, that you may have an issue with the transponder...
You know about the transponder-pill (chip) inside of your key and the transponder-reader-ring around the ignition lock?
Did you try all your keys to start the car?
Maybe check the wiring to the transponder ring...

 

I’ve never heard of the transponder-pill I’ll check it tomorrow. And I’m guessing the wires for the inertia switch goes to the ECM?

 

Not sure, where the wires go to - I would just check, if the wires on the inertia switch are connected.

Well, then read up on the transponder-pill (-chip). It's a kind of common fault. Have you check starting the car with all your keys? It may even happen that a key, which always worked, suddenly does not work anymore, Hence, the fault could be with the key or with the ring (ring not being connected / wire damaged, e.g by the steering column somehow).

On other Jag-models, there is a red LED light that blinks, if there is a PATS problem (= passive antitheft system = a problem with the transponder). NOt sure, if the X behaves similarly, but probably. Hence. read up on the PATS / transponder system of the X...

PS: That "beast" with many names (PATS / transponder) has another name still: immobilizer - and that seems to be the issue - that your car is immobilized...

 

Ok I just checked the battery and crankshaft position sensor.
The battery I got, 11
The crankshaft position sensor I got, 0
That’s not normal right? I should be getting some kind of reading on the crankshaft???

 

> The battery I got, 11

What does that mean? I hope you don't want to tell me that your battery has got 11V !?
If that would be true, you wasted money on 6 spark plugs and 6 ignition coils, while all you needed was a new battery and you are good to go...

 

Yea I got 11 volts, I’ll change the battery.
but what about the crankshaft position sensor?
I followed this video

You Tube

and my sensor never showed any voltage.

 

Not sure about the crankshaft sensor...- I never had to deal with that one....

With your no-start-problem, I - like everyone else = would normally ask about the battery - but since you replaced already spark plugs and coil, I figured you did already check the most likely problem-source - the battery...! A 11V battery is dead as a Dodo!
But also note: Is your multimeter, you measured the 11V with, OK and does it have a full little battery inside? Note that multimeters with in internal low battery might give you all kinds of incorrect readings...

 

And for future reference, NEVER throw parts at your kitty before you diagnose the probable problem or she'll hiss, and throw up a hairball at you costing you unnecessary money.

 

Most X-Type models have an Electrical Guide on JagRepair.com - Jaguar Repair Information Resource which if you look closely has far more info than most notice.

 

The car has been in possession about six years, when I first got it, a new battery was the first thing I changed, it?s the same battery I?m using now. It wasn?t until about a month ago I started working on it again. I figured the battery would be fine since it?s just been sitting there not being used

 

> I figured the battery would be fine since it?s just been sitting there not being used

That's what I call self-contradictory: If the car is just sitting there and you don't keep the battery on "life-support", it will die.
I permanently recharge all my unused batteries all the time - I have 3 CTEK chargers for that purpose (1 x 10A, 2 x 15A).