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According to the description in the SERVICE TRAINING COURSE 682 ADVANCED JAGUAR ELECTRICAL SYSTEMS, dated 2/15/2002, the Key Transponder Module (KTM) stored the key codes. When the transponder ring transmit a code stored in the KTM, the KTM outputs an OK TO START signal to the ECM via a serial data link.
That would suggest, in that '09-'02 window of model years, the ECM can be swapped out without any reprogramming.
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To be sure we didn't try something that wouldn't work I contacted "Motorcarman" by PM. He informed me that the VCATS has to match. Then the computers can be swapped but, either WDS or IDS would be needed to perform an IMMOBILIZATION SETUP. Without that your car wouldn't start with my computer. If you were able to do that, when the computer was returned to me, I would need to do the same setup as it would be looking for your car. I'm assuming you don't have access to either of the Jag programs and I don't, so it looks like a no go.
Ok, I just typed a response above and when I hit send, I had a thought. If an IMMOBILIZATION SETUP has to be done when the computer is installed in a different car, why was I able to install the "refurbished" computer I received for Foreign Auto Computers and start the car? Here is how they list the process on their website.
- Factory security - Anti Theft Systems - Most all vehicles after 1998 have an anti theft immobilizer security system in place that communicates with the ECM, ECU and with your key.
Reprogramming the immobilizer, ECM & key together is required after installation when an ECM, ECU is being replaced.
In most cases we can help you beat this system on most vehicles,
by moving the anti theft data from your original ECU over to a rebuilt ECM.
Then there is no reprogramming needed.
I am sure a member of this forum that lives in Florida that has IDS would be willing to help you out with the programming a new ECM if you elect to go in that direction.
The only other option is to send that ECM back to them or another place like ASI to see if they can find the problem.
If you can find one, get the exact same ECU from a same year car. Match numbers. Be careful... If it doesn't work out of the gate THEN start the process of getting things programed...
The KTM will recognize the key,,, the BPM will and hope is that the ECU will (if it's required) will as well... I think there is a good possibility that if the exciter, KTModule and the BPModule on the car says all is good, then your good. If not,,, get them feets ah moving onto nexts steps... programming of the ECU. Then you're on the road!
Something I didn't think of. Can you (with everything connected back together) do a resistance check to ground on one of the slate/green wires to four of the coil modules, and compare it with a resistance check to ground on one of the slate/light green wires on the other four coil modules.
Straight from the horse's (FoMoCo) mouth....Hi Jim! Thanks for the note. I’m a Forward Model Design and Release Engineer for ignition systems in Ford’s Engine Engineering group. We also have some ignition engineers in Research and Advanced, but with the big push to battery electrics our ranks are thinning out quite a bit. Still overall it’s a fun job as we get to work with quite a cross section of both Ford and supplier folks, and there are many interesting problems / learning opportunities that pop up.
Regarding your friend’s Jag, are there noticeable misfires along with the misfire codes? The plugs should get pretty sooty if there’s consistent misfire in a particular cylinder. Our Ford Service Techs will move the coil from one cylinder to another to see if the misfire follows the coil. If it does than the coil is at fault. Most of Ford vehicles use NGK sparkplugs which are nearly bulletproof. The plugs are usually an indicator of something else that could be wrong; the usual issue is a carbon or fuel fouled plug that’s caused by too many start / stops at the assembly plant, a fuel injector issue, or even a low fuel problem (had one of those pop up recently).
If all three cylinders started misfiring at the same time, it’s probably not the coils or plugs since the probability of them going south at the same time is really small. In that case you’d look for a “global” problem that could impact all three cylinders. Could it be low fuel pressure, or a bad UEGO sensor (erroneously lean out or richen the A/F mixture)? Low compression as you note could also contribute to misfire.
The Jag coil is a “Driver on Coil”. That one has 4 pins but ours have three. We don’t have a dedicated diagnostic feedback pin like that coil does. Say hi to Linda and have a nice evening Jim. Regards, Bob"
He does point to a new direction- are these O2 sensors wide band? Would not a bad sensor corrupt the whole bank, and not cylinders on both sides?
My biggest hassles are error codes complaining about the O2 sensor heater circuits.
These "misfiring" coils could be delivering a spark but the diagnostic feedback pin may be reporting low current through the coil. It'd be interesting to view ignition on an old Sun scope. Interesting that Fords did not use that feedback. "The Jag coil is a “Driver on Coil”. That one has 4 pins but ours have three. We don’t have a dedicated diagnostic feedback pin like that coil does." Whether that coil feed is weak or not, the ECM is digesting a weak signal (or not picking up a good signal) from the fourth pin. I say digesting as the microprocessor is coming to that conclusion whether the problem is external or within the ECM.
I assume the outfit that sent the reprogrammed ECM has security tape to void their warranty, but nonetheless, I'd break the ECM open and look for corrupt tracings or connections. The new lead-free solder poses a problem, over time, solder migration can creep out and short to places it shouldn't be conducting. I doubt there would be broken solder joints like the ABS module frequently has, but it isn't impossible.
Looking back through this thread, P035x codes have been reported. True? Those codes do inhibit injectors on the suspect cylinders.
johns55 validated the P035x codes in his post #146. We also did some additional checks offline that showed the non-firing injectors do actually fire for the first 5 seconds or so, which is in accord with the default actions and also eliminates the ECM -> injector wiring.
Originally Posted by jrnsr
These "misfiring" coils could be delivering a spark but the diagnostic feedback pin may be reporting low current through the coil. It'd be interesting to view ignition on an old Sun scope.
Indeed - or possibly, not reporting at all (or the ECM isn't seeing/responding correctly). A scope would be my tool of choice here, but not an option presently.
Just trying to eliiminate. Why cylinder A2 is working normally isn't clear at the moment.
johns55 validated the P035x codes in his post #146. We also did some additional checks offline that showed the non-firing injectors do actually fire for the first 5 seconds or so, which is in accord with the default actions and also eliminates the ECM -> injector wiring.
Indeed - or possibly, not reporting at all (or the ECM isn't seeing/responding correctly). A scope would be my tool of choice here, but not an option presently.
Just trying to eliiminate. Why cylinder A2 is working normally isn't clear at the moment.
I'll double check cylinder A2 just to make sure it's firing correctly.
According to the Wiring Diagram for 2000 MY, the diagnostic feedback pins on the coils are yellow-green #2. The three Y-G wires on misfiring cylinders join together with A2 and run through connector P11 to the ECM connector pin EM83-11. Maybe this has been explored already, checking resistance from coil plugs' yellow-green wires to both EM83-11 and to EM83-10.
Last edited by jrnsr; Jun 21, 2022 at 01:01 AM.
Reason: grammar
Yes - we got caught out with the wire colours - the wiring loom is from a '99. Jaguar kindly changed them for 2000, so the snip in post #105 shows the correct colours for this car. I did cross reference to the 2000 EG and could find no point-to-point wiring change 'banana skins'.
If you saved the old wiring, try plugging in the short section from the coils to plug P11.
Unfortunately, I didn't save the original wiring loom. I did do a continuity check on the new one and everything checked out. I did check cylinder A2 just to make sure it was firing correctly. I was show good spark and the fuel injector was working as it should.
After rereading the attached ignition description and then reading between the lines, I have to believe the Ignition Control Module pin 2 is normally low or 0V most of the time. When the ECM sends a Trigger Pulse, the Ignition Fail circuit goes high at first, then low "when primary current reaches 2 amps and is terminated at 4 amps." If unsuccessful, "the monitor line will remain at logic high, signaling an ignition failure."
That would indicate, the low signal is the key to no misfire. Since there are 3 other coils connected, those must be low when dormant also; if they were high, then there'd never be a low signal.
IF one or both pins to the ECM were removed, or #2 coil pins, from their plugs or the wires snipped, the ECM would never see a high signal. What would likely happen, all the coils would be identified as "misfiring" or none at all.
The ECM would be blind to misfiring from then on so a real issue of injecting raw fuel to the CATS could be expensive.
I've emailed Bob Humphreys at Ford a few more time to confirm this but have yet to get a response.
After rereading the attached ignition description and then reading between the lines, I have to believe the Ignition Control Module pin 2 is normally low or 0V most of the time. When the ECM sends a Trigger Pulse, the Ignition Fail circuit goes high at first, then low "when primary current reaches 2 amps and is terminated at 4 amps." If unsuccessful, "the monitor line will remain at logic high, signaling an ignition failure."
That is where I was hoping to go to implicate/eliminate the coil pack feedback by checking for the (aggregated) pulses on the slate/light green wire back to the ECM at pin EM83-11. The EG describes the pulse train as 5V @ 23Hz with the motor idling:
If we could either check for that frequency or, better still, see the pulse train with an oscilloscope, we could determine whether the fault lay with the coil packs or the ECM side. Since the other group of 4 is functioning OK, we would have something to compare with. Unfortunately not an option at the moment.
However, johns55 has moved coils around, but the DTCs haven't changed since day 1.
Originally Posted by jrnsr
IF one or both pins to the ECM were removed, or #2 coil pins, from their plugs or the wires snipped, the ECM would never see a high signal. What would likely happen, all the coils would be identified as "misfiring" or none at all.
The ECM would be blind to misfiring from then on so a real issue of injecting raw fuel to the CATS could be expensive.
That's why the ECM inhibits the relevant injector firing as a failsafe when it doesn't see a confirmation pulse for a particular cylinder for ~5 seconds.
Is there a way to one by one (OR only for the relevant lines to each coil) bypass the (new) loom and go from the ECU to the coils with something ya made up?
Meaning, identify the signal wires from/to the ECU at the ECU and coils in question, and with a temporary four wire loom that you made up, splice it in between the ECU and the coils, and temporarily remove the new loom sections from the system?
Personally, I think that measurements, readings and meters can get ya so far and confirm but so much, but if continuity readings and right resistance etc etc etc (according to a meter) aren't producing the expected results, something else must be going on.
