Guys,

I have a slight inconvenience… Every so often the car won’tstart. The dash lights up normally, PATS indicates all is OK, turn the key andno crank. Not even a try. Battery is fully charged (it lives on a CTekconditioner). Before I start to play, any ideas? I’m thinking starter circuit relay, possiblythe solenoid, it must be something electrical. There are no codes so I’m assuming it’s not a faulty sensor or genuinefault!
After a few minutes of playing, she’ll start upas if nothing’s wrong...

Thanks,

Doug

 

I'd start in this order: battery, starter, alternator, fuel pump/filter, injectors.

Start with the battery. The S-Type is very finnicky, and the moment the battery starts to even hesitate or lose a bit of power, it makes the car's electronics go haywire.

 

One item you may want to check is to ensure the "P" on the shift selector is lit red before cranking. Your shift cable might be stretched and sometimes the parking pawl doesn't fully engage.

If the "P" is not illuminated when turning the key to start. Shift to "N" then try and start the car.

 

It may also be a faulty ignition switch.

 

I would go for park first, ignition second, then get your wallet out

 

Guys,

Just a follow up on this...

I had an airbag fault that required me to dissassemble the steering column so I took the opportunity to check and clean the ingnition switch - Nothing obviously wrong there.

Park selection is fine - no fault there

Battery is good - definately no fault there.

Starter solinoid is good, starter motor connections cleaned and checked.

PATS light indicates all OK...

But I still get this intermittent starting fault!!!

I'm running out of ideas. Anyone got any more???

Thanks,

 

If it does the lamp self-test, PATS is happy, but does not even crank then stare at & work through the elec. guide as there are very few things involved in cranking. (Different stuff involved if cranks but doesn't fire.)

 

Hi Doug,

If you still have access, you can test the ignition switch electrically at its connector. The Electrical Guide shows the connections that should be made at each position of the key. Failure of the switch is not unknown.

The Starter Relay is also a suspect for your symptoms. In the Electrical Guide you can check it's position in the Front Power Distribution Fuse Box - there's a diagram near the front of the guide.

Another thing that can contribute to starting problems is corrosion or looseness of battery power connections, such as the front bulkhead connection and any fuse box connections in the circuit, and the various ground points, such as the battery negative ground point on the body and the engine ground strap.

Corrosion on the electrical connectors for the Engine Control Module (ECM) could be a contributor, or water ingress into the ECM. (The cranking control circuitry is built into the ECM).

As JagV8 suggests, study Figure 02.1 in the Electrical Guide for suspects. You can download the 2003 S-Type Electrical Guide here:

http://www.jagrepair.com/images/Elec...al%20Guide.pdf

When you mentioned in your first post that there were no codes, did you scan with a standard OBDII/CAN scanner that can only read the generic P (Powertrain) codes, or did you use a system capable of reading the proprietary Jaguar B (Body), C (Chassis) and U (Undefined, mostly network-related) codes?

Cheers,

Don

 

Don,

No codes with a Mongoose clone and SDD/IDS...

Ignition switch looks good... I'm going to try cleaning all the main electrical earth points and likely to replace the starter relay... I just seems the obvious culprit (and I'd like to have a spare)... Troube is the problem is so intermittent, it's hard to replicate when I have all the tools ready. It only seems to happen when I'm running late or in the carpark with a boot full of groceries!!!

Thanks,

Doug

 

Good plan. Sadly you have one of the annoying problems that can hit any car.