I have an 05 s-type automatic with the v6.

My car has an intermittent starting issue that I can't figure out and would appreciate some ideas. When I try to start the car the following happens:
The engine doesn't attempt to crank, it displays engine fault light, the red and yellow fault light, transmission fault, park brake fault, abs fault, and DSC unavailable. When this fault is occurring I cant connect with the OBD reader, the brakes stiffen up and I can't change gears with the key in the ACC position. Once the car does start, it seems to run fine with the exception of the faults. Once it starts once it will continue to start for a period of time. After turning the car off and restarting it, all the faults and warnings go away. Sometimes if i hold the key in the start position the car will start just start up after a few seconds, but most of the time it doesn't. I usually just have to wait a few minutes or a few days and then all of a sudden the car works again.

I was able to pull the obd code P1797 CAN TCM/ECM Circuit Malfunction
out of it one time when it did allow me to connect.

I would appreciate any input you guys have and please just let me know if I need to include any more information.

Thanks
Brad

 

Hey Brad, I also have an '05. If you have a Jaguar factory battery still my bet is you need a new battery. When a battery starts to fail the vehicle pops up all kinds of goofy codes and faults. Many of us this past winter season with '05s have experienced similiar problems and it was due to the battery begining to fail.

If you would like to research more do a search on "battery" and look in the S Type section. Good Luck


BTW welcome to the forums and next time you have an S Type question put it in the S Type Section here. You will get a faster reply in most cases.

 

I agree with Rick - first go after the battery. If you consistently drop below 12.1, 12.0 volts, you can get errors like these, yet still run the starter. Once the battery gets below 11.1 then really crazy things happen electrically.

Now, if you check out OK with the battery, or end up replacing it and still have the fault, P1797 shows a CAN bus fault between the ECM and TCM. THis is the major network protocol and connection between the TCM/ECM. I've seen corroded connectors on the ECM causing such CAN bus errors too. With the battery disconnected, pul the ECM harness and use a contact cleaner on both connectors. Do the TCM too.

Best,

 

I checked the voltage and it was 12.5. I left it in and jumped it to another car and the voltage went to 12.7 and the problem still remained. I will probaly buy a new battery tommorow just to be safe. I have already cleaned all the connectors that I could reach for these systems. I was looking at an 04 stype wiring guide and I see that the only common thing between all these systems in the battery voltage and the instrument cluster. The manual calls the cluster "the network gateway". I thought maybe the instrument cluster was maybe bad since the different systems or on two different data buses and that since the OBD reader couldn't connect either. The manal shows that the OBD connector talks directly to the instrument cluster via a data bus. I suspected that maybe the CAN data bus was bad between the TCU and ECM, but the park brake module is on another bus.

Thanks for the advice guys. I will try a new battery and let yall know what happens. I have been having this problem for a few months now, but it has gotten much worse recently.

Brad

 

Before you buy the new battery - 12.5v is pretty normal. If you're maintaining that after the car sits over night, for example, then you are OK on battery. Although, if you know the battery is old you might want to replace it anyway.

The suggestion to examine/clean connectors is the easiest of process of elimination steps, but does not preclude module failures anywhere along the bus. Second easiest step would be to look for damage to any harness along the path.

Best,

 

moved over here to the S-type Section as requested...thanks for the heads up jagV8

 

Not at all - thanks for moving it.

Let's see if a new (hefty-spec) battery fixes it. I agree it's the most likely, unless some work was done around the time the problem started.

 

Well I tried a new battery today and the problem still remained. I guess I'll try some cleaning some disconnects between the instrument panel and all the malfunctioning modules.

This may be a stupid question, but if I change the instrument panel will that affect the mileage readout of my vehicle or is that stored elsewhere.

Thanks again for the input

 

Don't change it - car will not start, I think. Dealer can reprogram but get a price first.

It's not a cheap swap, either.

It could be any of quite a few things, but the steering lock / SLCM is more likely.

If you can get it to go wrong at will then a dealer can probably diagnose/fix it.

 

As I do believe I've mentioned at another time, there's a routine when you suspect a battery may be the culprit of multiple errorcodes.
1) Check/clean any sulphation at battery terminals.
2) See that batt. -ve. ground strap is good connexion, no rust and tight.
3) Check engine ground strap is rust-free and good & tight.
4) Check alternator output terminal is good & tight, but not overtightened.
5) And for good measure while you're at it, the starter motor connexion.
Leedsman.

 

Well thanks for the ideas guys. I changed my battery just because I didn't want to have that hanging over my head. The problem still remained. The car has been messed up for 4 days now. I moved the steering column around and then it work. This may be a coincidence, but I'm not sure. I pulled and yanked on all the wires around the column but it won't mess up again. I have been fooled in the past by moving things and then all of sudden it decides to work. I not sure what to do next.

JagV8...You think the SLCM could cause all of thoses failures on the modules on the CAN network?

Thanks again for the input

 

I'd like to think that nothing could cause the list of things you got!

What I'd do would be to do an OBD scan of all the modules to see which ones have stored codes and what the codes are, hoping for useful clues. You need a dealer-type tool (and a competent tech) or AutoEnginuity for that.

As things are,you don't have much to go on. The SCLM has caused problems before, so by known frequency of problems is a suspect. So are the harnesses at the car front and inside the wheel arch (wheel well) liners.

I bought AE because I figured it wouldn't need many trips to a dealer for diagnostics to pay for itself, and my past experience of trying to find a competent tech (for a simpler, non-jag) was dire.

As you've swapped the main battery many of the codes will have gone but when the problem recurs (I think it already has) they'll be back.

 

Well it started working again. Do you know what the resistance of the CAN network should read. I was wondering if I could just ohm the can bus out next time the fault occurs.

 

Fault-finding with values - see workshop manual. Far too many picky details to post here.

 

Thanks for the help. I'm going to look into a few things this week.
Brad

 

We recently had four situations that involved starting when it want to two relating to the shifter and two related to a fuse block at the battery where the power would be distributed to the many fuses and relays. I do not have a oneline of your car but on my 2000 I found a Transit Isolation Relay and two mega fuses. I would be checking them, two of the cars the fuse blocks were cracked causing the intermittent start. Cracked by the loose tire in the trunk. The other was a shifter selector switch and I think you checked it. If you have not, the next time it does not start move the shifter from “P” to “N” and give it a try. You should consider the possibility that the ignition switch having a problem. I did see a post suggesting that the wiring going to the ignition switch had a problem but I am unable to find it again. If you need a oneline of the car the only one I could find is for a 2004 s-type http://www.captainjaguarscathouse.co...ec%20Guide.pdf