Car is a 2005 Jaguar S-type R

Recently I had a post regarding misfiring and suspected it was the coils as there was no error codes. Had the coils changed last week along with all new spark plugs. Now a new problem appears, at speeds higher than 80km/h when I accelerate always throws the same code P1643, Gearbox Fault, Parking brake fault and restricted performance.

Went through some historic threads and saw that this may be a battery issue, battery is less than one year old and had mechanic test it out this morning and battery appears to be at full strength. At a loss here. When the car is driven on city streets, no issue. Same with freeway speeds as long as you baby it. As soon as speed threshold crosses about 80 km/h and you give it more than half throttle it throws the code.

Also, simple reset when this happens. Turn the car off and leave off for about a minute, upon restart all is cleared and fine.

Any suggestions or clues as to what may be going on would be great!

Cheers,
Adam

 

Could be a power/ground problem. (Which is what a poor battery mimics.)

But of course it could be a CAN issue as the code says.

 

BTW not sure if this makes a difference or not, I did not use OEM coils, I bought the Standard Auto brand from RockAuto.

Just spoke with my Indy, he suggested I go ahead and install factory coils and see if the problem persists.

 

This sounds like good advice because there are lot of complaints about the after market coils. Some firms are good and others are bad. However first what is the voltage of your battery as it will be one with cadmium in the plates it should be over 12.7 volts.

In my car the alternator only supplies the full charging voltage for 5 mins of 14 volts after starting the car. It then drops which means that I have to put the battery on a charger once a month to ensure that is fully charged.

 

Hello all thanks for all your responses.

So first item was checking the battery. Here is the numbers I got:

11.5 when cranking to start
14.5 when the car is running
12.5 when the car is off

Thoughts?

 

Its a bit low, put the battery on charge for 10 hours and then turn your lights on for 3 mins. Then read the voltage it should read 12.7 volts minimum.

If you check the voltage in the Cuban cigar lighter you will find that it is below 12.5 Volts at the moment because the battery is a long way away being in the boot/trunk and there will be a loss in the voltage.

This may be why you are getting the codes etc.

 

Here is the Battery standards for the amount of voltage.

12.68v . . . . . . . . . . 100%
12.45v . . . . . . . . . . 75%
12.24v . . . . . . . . . . 50%
12.06v . . . . . . . . . . 25%
11.89v . . . . . . . . . . 0%

If you check the 14.5 Volts is the initial charging rate and it will later drop to 13 some thing volts (This happens in my car after 5 Mins)
This means that I am unable to charge the battery above 80% in my car and that is why I have to charge the battery every few weeks.


I had restricted performance from a Knocking sensor which would have cost a couple of hundred to replace when all the gaskets are considered as well, this turned out to be a low battery.

The computers need to have 12.5v when the car starts or you will get false codes.

 

Start the car and check the voltage then turn the lights on and the A/C/Heat on auto then check the voltage. This should put load on the system and let’s see what you have then.

 

It's labourous but if I were you I'd check connections.

I purchased a stype r with restricted performance on dash. Cleared codes. 600 miles light on again. When looking at wiring all codes were related.

oxygen sensor. Throttle motor. Charge cooler pump and one other.
I cleaned the common earth. Swapped relays and closed up connections on relays and fuses. 1000 miles no light.
when I was a tech I never believedid about bad connections on cars in a dealership. As our cars age they are going to be sensitive to poor connections and bad earth's as opposed to module failure.

I'd check can network connections between tcm and ecm. And any connectors in line. They are very sensitive to high resistance.

 

I

 

Will start on the battery charge first and then the connectors.

I guess the unanswered question is, is it possible that the aftermarket brand new coils have cause this issue? Only asking as it only showed up as soon as I picked up the car from the indy mechanic after changing plugs and coils.

 

Read this post it happened to him 3 times.
https://www.jaguarforums.com/forum/s-type-s-type-r-supercharged-v8-x200-15/coil-pack-failure-again-89670/.

 

Well I can't say it's the coils but follow your error codes first. If the coils were giving a problem you should have misfires and the codes for that. But you do not.

I would keep looking elsewhere and I think you are on the right track with the battery.

Let us know what you find out.
.
.
.

 

Thanks for all the suggestions. Car is now with the local jag specialist. I will update as to what he figures out.

 

So Jag specialist in my city pointed to the throttle body after having the car for several weeks and doing multiple tests. I replaced the throttle body and the problem remains. In the meantime I fully charged the battery over 24 hours to rule it out and went for a spin right after taking it off the charger, same issue.

I'm at a loss of ideas here. Last resort is to take it to the Jag dealer, but at this point I'm wondering if they will be even competent enough to diagnose it.

Any other ideas? From reading on here I see some suggestions that it may be the TCM?

 

Did the workshop manage to cure the misfire or do you still have that as well.

 

Try this.

have somebody in the car with you and get them to look at the shifter illumination to see if it goes out when the problem occurs or stays on. It should show what gear your are in.
If it does not then that indicates that the tcm could be faulty. The only way to check this would be to use the SDD/IDS program and a mongoose or vcm.

 

Are the symptoms still the same?


6-speed transmission, right? What if you manually select 5 or 4 and then accelerate above 80kmh? I'm wondering if that would change anything, and doesn't cost a thing to try.


Based on the history of when the issue started, I'd be willing to gamble on a new set of coils. It would seem you'd have had some misfire codes with suspect coils, but who knows. The misfire monitor is loosely based on only one or two cylinders putting out low power compared to the others. If all cylinders are down uniformly, or nearly so, the misfire logic monitor may not recognize that as a problem.


Next up on the shotgun list is the battery. Even though it's fairly new, your exact messages have been repeatedly caused by a marginal battery. I have a crackpot theory about the battery finickiness for which our cars are famous. It may not be exclusively voltage related. The battery also acts as a giant capacitor to smooth out the normal AC ripple from the alternator. This importance capacitance function is also affected by the length of the battery cables, so the remote battery location makes the S-Type more susceptible to this issue. I must stress this is only a theory of mine, but is something to consider once you reach desperation level. It's possible for the capacitance capability of a battery to decrease below a required level while the voltageness (that's a word I just made up) is still within specs. Normally the two functions decrease roughly at the same rate. If you don't want to spring for another battery, do you have another vehicle from which you could swap for troubleshooting?


The other thing to consider is the battery ground cable-to-chassis connection. This bolt passes through the wheelwell, and the tip of the bolt is exposed to road salt, etc. Corrosion can easily form inside the assembled threads. It would be worthwhile to disconnect the cable-to-chassis connection and give everything a good cleaning. Clean up the female threads with a tap. Wirebrush the surface where the cable is bolted to the body, and the cable end, too. Reassemble everything with some dielectric grease (like used on spark plug boots, Dow DC4 for example) on all surfaces, including the threads, and see what happens.


Re-thinking the order, based on my rampant laziness and Scotch-like cheapness:


1) Clean up ground cable connection


2) Battery


3) Coils

 

Thanks guys. The misfire is cured, no issues with that.

In talking to the Jag indy mechanic last night, he suggested that after installing the throttle body (I had it done myself) that it should be re-calibrated and the ECM and TCM should both be re-flashed which can only be done by the dealer. Any truth to this?

 

Details about the throttle body / gas pedal calibration:

https://www.jaguarforums.com/forum/s...ection-176446/

FWIW, after replacing the throttle body (intermittent P1584) on my '02 V6 a couple of years ago, I didn't know about the calibration procedure. I just reconnected the battery and drove away. No problems. The newly installed unit was used, so maybe the calibration requirement is only mandatory for a new unit.