Tried about every thing . Need a good electronics guy.Thanks

 

Welcome to the forum mabbas20,
Please post an intro in the new members section when you can.

It would be good to have some more details, what happened before the fault and what is the everything that you have tried?

 

Ok here goes. If i jump the starter relay it cranks. I have power to the control side of the relay but there is no ground from the ECU.

 

Have you checked the inertia switch?

 

I checked the inertia switch and just to be sure I reset it
it must have been tripped because I am getting a code called Flight Recorder that my scanned can't erase.
do you know how to read the Jaguar wiring diagram?

 

It's probably me ,but I think there might be an error. If anyone can clarify I would appreciate it.

 

What is the actual code you are getting?

When you jump the starter relay does the car start or just St turn over?

 

Could be your main ground strap. Happened to me. It might look fine, but the crimps sometimes lose good contact.

 

I'll check thanks. Could that be ?all else seems to work even the heavy draw of the starter

 

It will only crank .. the two unreadable codes are P1582 and P1000 .

 

I mean the scanner can't erase then

 

I've read P1582 can happen on an engine stall. It cannot be cleared from a scanner.

Between your key and the starter relay there are several items that could potentially be faulty. So, according to the circuit diagram (schematic):

Key transponder → Column Switchgear (reader/exciter coil) → Key Transponder Module → Body Processor Module → ECU → starter relay. Other inputs into the BPM which could affect starting include the Inertia Switch, the Ignition Switch and the Not-in-Park Switch. There are also inputs from the passive anti-theft system section of the Major Instrument Cluster to the BPM. This all from FIG. 03.1 of the 2003 Electrical Guide for the XK8/XKR. There are of course the wires and connectors in between which are identified in the circuit diagram. I would suggest working backwards along the chain. You already did the first step which is no ground from ECU to relay. Was this at the ECU or the relay?

 

I don't have an active ground on the relay in the start mode.The wire runs from the ECM to the starter relay. If I ground it with the key on the car will crank. If I spray it with starting fluid it will run for a few seconds. Do you have a schematic to look at. If not there is one for free on Jagrepair.com. there is a start charge diagram. . Could you take a look at it . The car is a 03 Xk8 4.2

 

Google that code for jaguar and you will see a lot of helpful info from past posts but sounds like a fuel issue also involved

 

JagRepair.com - Jaguar Repair Information Resource

Electrical
2003 XK8
Page 47

" If I ground it with the key on the car will crank."

So the key has to be in the ignition and turned on before it will crank? That's another clue.

 

Jaguar figure 3.1 battery,starter,generator.
looking at the ins and outs for the ECM looks like the crank signal from the BCM at connection EM80-6 and the ground for the relay at EM80-41 are missing.

 

CKP sensor not working?

If the PCM is otherwise happy it times injector pulses using CKP.

If the car won't crank at all, trace the power through. Swap any relays.

 

Thanks, I checked the relays and fuses. I think the crank sensor might be ok because I have spark when I jump the relay . I am hoping it's not
a control module.

 

I tried scanning the transmission module and I am getting some weird stuff. It's saying it in neutral when the shifter is in reverse. Also does anyone know switch L1, L2, L3 L4 are and which ones should be active or inactive. The car took a pretty good hit. I am wondering if the switch on the valve body could be causing my no crank?

 

If it thinks it's in neutral when the shifter is in reverse, maybe the Not-in-Park switch is on when you try to crank in Park.