On the coils I have 12 V on the White / Pink wire but no timed grounds on the ECU it provides on the return green wires for all 6 cylinders ?

All ECU ground points provided .

The reading is 25 ohms static or rotating and in theory should be 0 and open as it sequences .

Brain not working today

I thing somehow it is immobilized of inhibited , I'm talking about the car .

Fully charged battery 12.84 v

 

Hi Parker,

I'm tired too, but it would help to have a bigger picture of the symptoms you are diagnosing and if the onset was sudden or has been coming on for some time.

If the engine is immobilized, the engine will not start. If the engine will not start, the ECM will not trigger the coils or injectors to fire.

If the engine is running, how are you trying to measure the pulsed grounds as the ECM switches each coil on? I haven't tried this on an X300, but I would think you would need to set your meter to Duty Cycle or use an oscilloscope, but you might possibly be able to measure some voltage with your meter on the AC Voltage setting.

Have you confirmed no spark?

Sorry I don't fully understand the issues you are dealing with.

Cheers,

Don

 

US versions of the X300 have no immobilizer. Could be just electrical gremlins who are disrupting the norm?

 

CKPS or inertia switch????????????????

bob

 

Thanks Bob I thought of those yesterday and verified .

The engine ran 6 months ago .

With the fuel rail pressure holding steady with a solid check valve I can watch it lower as the injectors spit .

Starter fluid will not light off so I suspected ignition .

Cleaned the plugs and reoiled the cylinders for possible bore wash .

New fuel .

Power to the coils but the timed grounds are not present as I watch with a needle meter .

So I suspect the ignition is inhibited .

I think it's somewhere between the SLCU and the ECU as I was helping others out because I like to tinker .

Noticed that somehow I'm missing power on the supply side of the fuel pump relay so I jumpered power on the output side for fuel pressure . King relay in truck clicks and swaped . Battery terminal not the best bite and will replace .

My brain never woke up yesterday so I tagged out but will look at it again later .

 

Hi Parker,

I still feel like I'm not understanding the full picture, but I gather from the above that the starter motor runs and the engine cranks/turns over/rotates, but the engine will not start. It would start and run six months ago but has not been started in about six months. Is that correct?

You mentioned in your first post that the fully-charged battery measured 12.84V. Have you watched the voltage sag while cranking the engine? If the voltage falls much below 11 volts while cranking, the ECM may not trigger the ignition to fire.

I don't know if you will be able to see the pulsed grounds to the coils on a needle meter - they happen so quickly that a standard voltmeter may not be able to react to them, especially a meter with averaging/RMS type filters. I suspect that to see those pulses you will need a digital meter that can measure duty cycle or frequency or an oscilloscope. A much easier test is to pull one coil and spark plug, pop the plug in the coil and reconnect the coil to the harness. Ground the threaded sleeve of the plug with a battery jumper cable and watch for spark while you crank the engine.

You have new fuel - are you certain there was no water in the tank prior to filling with gasoline?

Cheers,

Don

 

Good points with the pulse of the needle may not be seen as well as the possibility of water in the empty tank as it was emptied over the winter .

Car ran 6 month ago .

Good starter rotation .

Going to try " Hard Reset " later as I was tinkering with the SLCU wiring for someone .

 

I am about 6 years late to the party but I appear to be in the same situation, I put a new battery and have replaced spark plugs, coil packs, cleaned grounds and connections, even ordered a new ecm (have not cloned yet). I have fuel and crank and traced all wires from the 8 coil packs to their respective connections (10 pins on the ecm, plus their main power supply and ground) but don't seem to be getting spark. How did you resolve this?

 

2004 V - 8 four door ?

That would be either a X308 or X350

 

How did you confirm that you are not getting spark?

 

Hi Itnkth4,

Welcome to the Jaguar Forums! It's great to have you with us.

As Parker suggested, we need to know the year, model and engine of your Jaguar in order to give you the most accurate input.

The two most common causes of no-spark on all cylinders is low battery voltage while cranking (if it sags to about 10.5 volts, the ECM will not trigger the ignition), or a failed crankshaft position sensor. The ECMs almost never fail unless they suffer water damage.

Please let us know your vehicle details and I'll move your posts to the correct forum.

Cheers,

Don

 

This tool sells for $5 at Harbor Freight. It is an easy way to determine if you are getting spark.