Cannot Start STR

[SteveKK]

I think this is an electrical/sensor issue, but here are the symptoms. The car is a MY2002 STR.

Went to start the car this morning and everything appeared normal, but I got nothing when I turned the key into the Engine Start position. The following message are looped in this order:
DSC Not Available
Gearbox Fault
Park Brake Fault
ABS Fault

My initial thought was a low battery voltage, which I measured at ~12.2v, so I followed the handbook instructions to jump start from another battery. This made no difference at all.

The handbook says not to run the other car while jump starting, since this will cause damage to the Jaguar electronics, therefore I was still seeing only 12.3 -12.4v on the Jaguar, even though I had just started and run the other car to put a charge through that battery.

What should I look at next, as the Jag is blocking my others cars on the drive.

Regards,
Steve

[Montana5]

Steve, did the car unlock ok with the key fob, can you check the tightness of the earth strap and the positive lead from battery and any earth straps you can see in the engine bay.

Doug

[SteveKK]

Doug,
Thanks for the quick reply.

After reading your post I removed the earth strap and cleaned both ends, plus the -ve terminal. It still wouldn't start and the voltage was 11.85v. So again I boosted with a second battery, which ready 12.2v under no load (not the one I used earler as this is 'spare' in the garage).

Tried again and still no luck. Shut the drivers door and tried again - error codes gone and engine starts! How fickle these electrics are.

Looks like I need to get a new battery, as late last year during a cold snap it did turn over and not fire when the temperature was -5C outside. That time just switching the ignition off and on fixed it.

Regards,
Steve

[Montana5]

Glad you got it started Steve, could well be a bad cell in the battery, have had that before myself, would be interested to know how old your battery is, my own is a 2007, so getting close to replacement time. I've never before come across a Car where the electrics are so fickle, its almost as if some components are going to sleep and just refuse to waken up.

Doug

[SteveKK]

I'll see if I can find a date on the old one when I replace it tomorrow. It looks like a genuine Jaguar battery in there and I've got a Yuasa 091T as replacement.

Regards,
Steve

[Martec]

I recently had a 'limp home mode' issue event though the battery was in good condition. From advice from friends I used one of those battery terminal bottle brush type wire brush cleaners on the battery and terminals (I was surprised to see the posts were white from minor corrosion).

As mine is a standard car I stripped and cleaned 10 eyelets on 9 bolts(these were also a little rusty, particularly in the engine bay and under the front wings). I also found and cleaned 4 +ve terminal posts about the car. I still can't find 4 of the earth points. I also pulled and refitted every fuse and relay twice to clean the contacts.

The upshot was with the battery disconnected for over 20 minutes (4 days) there were no codes showing, none on the scanner and none appeared to date (fingers crossed).

Twice now I've heard of the trick of disconnecting both battery terminals and holding the cables together, I assume it saves waiting 20 minutes as it discharges the capcitors??? Anyone hear of this dodge? Sounds a bit dodgy to me.

Brian

[J44EAG]

I would avoid terminal touching at all costs. Electronics are very sensitive and if any have some capacitance within the circuitry, it could cause issues.

Switch packs need an absolute minimum of 12v DC to fire modules. Any less than I guarantee the car will not start.

White powdery deposit on battery terminals is lead oxide. A good clean up and a thin film smear with Vasaline helps keep corrosion at bay.

Look for 12.8 volts off load with the engine off. That is a reasonable battery. 12.4 volts and you are looking at a partially discharged battery. A start may be possible...just.

I condemn any battery I find below 11.5 volts. It is unlikely to recharge and will in all probability fail again shortly after.

Batteries are consumable items like oil and oil filters. Most batteries will begin to fail after around four years. Any longer life and you can regard it as living on borrowed time. I`ve earned a living from DC electrics in the worst possible environment...marine. I`ll refuse to take responsibility for any electrical installation that has suffered electrical failure due to batteries being below 11 volts when I arrive on the job. Change the battery, Guv, or I walk away.

Batteries start life at 1.8v x6 cells after receiving electrolyte and before receiving their first charge. Minimum terminal voltage for a 12v nominal battery should be 10.8v. Therefore a battery showing 11volts in service is best regarded as a dead `un. Don`t waste you time trying to recharge. Finished, and that is all there is to it.

There is no reason why a jump start from a car with the engine should do any harm at all provided you apply the following. A battery does not know or care if it receives a recharge from another car, its own alternator or from an external mains powered battery charger. It just isn`t that clever!

Switch off the "donor" car engine. Connect the -ve leads in any order to the donor car and the dead car. Connect the +ve lead to the donor car, then connect that live -ve cable to the dead car. Immediately start the donor and let the donor build up a charge in the dead car battery for a few minutes. Do not try to start the dead car immediately as damage to the dead battery is likely to occur.

When you disconnect, disconnect a -ve lead first, then the +ve lead from either car.

Cold weather will find out if your battery is any good. Clod weather failures predominate at this time of year. A battery that was good yesterday and fails today under such conditions is not uncommon. I`ve seen five cases since the middle of December on boats and cars.

I have a Draper drop test unit which I use to interrogate batteries. Cost around £100 and worth every penny. No more guess work as I can test and see exactly how a battery performs under load.

Remember a battery can fail in two basic ways or a combination of both issues. Scenario one, a battery failing due to low terminal voltage. Scenario two, a battery fails due to lack or capacity. Scenario three, a battery can fail due to a combination of both defects which is the most likely cause of any battery failure in cold conditions.
Regarding the dead STR, chaffing and breakage of the wiring loom under the air filter box has been known to bring an S-type to a stationary lump of obstruction! Locked in Park as a result, I`ve heard of a case where a recovery truck had to drag an STR down a tight residential street with wheels locked before being able to take the car off for repair!!

Jaguar electrics and electronics do cause issues. I`ve had intermittent reverse sensors for months, and for two years, no auto steering column retract or seat retract on removing the key from the ignition. Tonight it all got going again!

View other electrical posts in the Electrical section of this BB. There is much battery info previously posted.

Mike K

[SteveKK]

Doug,
Sorry for the slow update, but time is tight once the working week starts.

The battery old battery is a Jaguar branded Varta battery with what looks most like a date stamp showing 0219, which I would guess to be week 19 of 2002, therefore the original battery on my 52 plate car. At over 10 years old it gave good service and could possibly be revived too, since it was only marginal.

However, as I want a car that will work when I need it to, plus provide creature comforts, I'm happy with a replacement battery.

Regards,
Steve

[SteveKK]

Well, once week on, I go out to the car, clear the snow off it, turn the key and get the same error messages as last week. This time my multimeter is at work, so I can check the voltage, but as it's a new battery I'd be surprised if that was the cause, but cannot rule that out completely. The condition indicator on the battery it green, signifying it's in good health. Trying a jump start didn't work.

Remembering the advice from Doug about checking earth straps in the engine bay and remembering that around the near side front wing might be a problem area, I started looking there. Not many earth points on view, but then I spotted one hidden by the air box onto the front of the car, so I removed that and unbolted the strap.

After giving it a clean, both the eyelet and running a tap and die over the bolt and hole I decided that it couldn't hurt to add an additional earth strap to another suitable point on the car, as you can never have too many earth points. Therefore I made up another, with I bolted to the same point and extended to the bolt hole for the air box.

Upon reconnecting the battery the car starts OK, so maybe I do have an earthing issue in the engine bay, rather than a battery problem.

Another good piece of news is that the CD Changer, which hadn't worked for a couple of weeks is also working again, so when the weather gets a bit warmer and drier I might go hunting for earthing points and give them a clean.

I'll try to remember to take photos, as putting something like this together could be a useful guide, unless someone has already done this?

Regards,
Steve

[SteveKK]

Still being a problem, as I haven't been able to start the car for a week now. Therefore I've been trying to look into where the problem is exactly. I've been using the information in the link below, which is possibly guiding me in the right direction.

http://www.justanswer.com/jaguar/6zusn- ... alarm.html

I've also been looking through the electrical diagrams I've downloaded from http://www.jagrepair.com/Default.htm and feel that I might have an earthing issue.

So, my question is, do I need to remove the wheel and wheel arch lining to access the earthing point within that area? Doing so might be a pain, as I'm currently parked on grass, so jacking will be tricky, but not impossible.

I've also been offered phone assistance from the neighbour's son, who is an expert on car electrics, having recently replaced a complete wiring loom in a modern Range Rover. He think he can talk me through some diagnostics with a multimeter to find the fault.

I'll report back with any findings.

Regards,
Steve

[J44EAG]

Re my post above, have you examined the loom under the air filter box?

"Regarding the dead STR, chaffing and breakage of the wiring loom under the air filter box has been known to bring an S-type to a stationary lump of obstruction! Locked in Park as a result, I`ve heard of a case where a recovery truck had to drag an STR down a tight residential street with wheels locked before being able to take the car off for repair!!"

Mike

[Martec]

Not sure if I've missed a point, but every time you have disconnected the battery it will start directly afterwards???

Disconnecting the battery for 20 minutes wipes the fault codes. An STR will have more gear than mine, but as its post 2001 it is fully OBDII compliant so a friend with a code reader can pick them up. But you need to be wary, my fault codes directed me to a faulty throttle pedal, but as I had had the inlet manifold off I looked at the wiring to the throttle position sensor. I found a wire partially rubbed through, insulated it and refitted plus cleaning of all earths and fuse/relay contacts seems to have worked its magic............. so far.

Earth points the earth points that I found really dirty were easily visible behind the headlights and one on either side behind the front wheel arch liners, one is the main engine/starter earth and the other side is the earth for the 'powertrain control module' or 'general electronic control module'. Yes it is easier access to work with the wheel off and wheel arch liner out.

This is all relevant to pre march 2002, but applies to V6 and V8 I think.

Best of luck

Brian

[SteveKK]

I've checked the earth points in both wheel arches and they were clean and providing good continuity. Diagnosis with a multimeter and the wiring diagrams is pointing to an issue with the CAN bus and a chat with a Jaguar trained specialist mostly confirms this. He is trying to borrow the Jaguar diagnostic equipment from work, so we can see what the error code is. The wiring loom under the air box and through both wheel arches looks in good condition, although I did put some titan seal over a potential sharp edge in the N/S wheel arch.

I suppose the next issue is finding all the modules on the bus to check those connections and see if cleaning and re-seating will cure the problem.

Frustrating as hell, but I'm sure it will get fixed soon, but so much for the comfortable cruiser for the winter months - I might just stick to my Xtreme!

Regards,
Steve

[Montana5]

Steve, did your Mechanic friend explore the inhibitor switch at the shifter, even try moving the shifter a little sideways, next time it won't start, I know the shifters can become slack over time and can be tightened from below, just thinking as its an intermittent fault, the inhibitor switch could be interlinking sometimes and not others.

If wiring is the problem don't forget the infamous behind the front bumper broken loom wires.

Doug.

[SteveKK]

Finally got the STR back this afternoon. The fault was eventually traced back to the wiring loom behind the bumper. For now they have run a bypass wire and everything is good, but I will book it in with a Jag specialist to be properly fixed.

My first issue with a modern car has taught me a lesson - use a Jag specialist.

Regards,
Steve