Flashing lights on J gate

[chrisipj]

XK8 2003 4.2 6 speed
Put car in garage in November transmission all OK. Battery has been on float charge.
Started at the weekend (0 deg C) and the indicator lights on the J gate now want to flash. Seems the same in every position. Moved car back and forward but still the same. I have not driven it on the road as it is SORN.
Any ideas?

[mike020150]

It sounds like one of the gearbox initial checks has failed. Always start with the simple stuff. Before assuming something expensive may have happened, wait until you tax the car and take it for a decent run. If that doesn't alter anything, move on by disconnecting /reconnecting the battery (after looking for the radio code). Mike.

[PTR200Jag]

Had similar problems with dash lights in all combinations when I have left mine in the garage for a long period too and it was connected to a trickle charger.

As Mike says, get some miles on it and see if it clears, once I started using mine again it took around a week to get rid of oddball lights that came on at random.....funnily enough leaving it outside, in the cold instead of a warm "ish" garage!, seemed to concentrate its mind and all the lights stayed out

The only lights I would be concerned about is anything that brings up the RED light in the dash.... then you need to get a code reader in the tool box too

[chrisipj]

Thanks for suggestions.
Ran car up the motorway for about 20 miles. runs well and gearbox operates normally in D. Kickdown ok but sport button does not work.
Gears 2 and R work on LHS of J gate when parked, not tried the rest yet. Sport switch seemed rough so changed, no difference and all selected lights still flash when selected. Disconnected battery overnight, still flashing.
Any further suggestion welcome

[mike020150]

The software runs checks on the gear lever position vs the gear selected. If wear or physical damage (eg someone attempting to move the lever without having a foot on the brake pedal) has upset this relationship with the linear switch below, it will cause the lights to flash. Adjustment may be possible or it may require replacement of the switch. Mike.

[Andy P]

Hi chrisipj,
Sorry to hear of your problems,from what I understand of these cars(Ihave an XJ8 myself but they are very similar)the flashing lights on the J-Gate is a warning that the TCM is not communicating properly with the ECM. The first thing I would do is check the motronics connector on the transmission,unplug and make sure it hasn't got any corrosion on the internal connectors and refit,If you have a Workshop Manual it will tell you where the plug is located.Then I would look at the harness for damage or other loose connections. Then verify that the shift cable is secure to the transmission, the two bolts are known to come loose. Finally,I would open up the J-gate assembly and check the micro switches and connectors.
I know all that probably sounds a bit daunting but if the car is driving alright it's probably not serious just annoying .
Good luck anyway and hope you get it sorted.
Andy

[chrisipj]

Next stage. Took the car to a garage to have it plugged into diagnostics. Told it was the rotary switch on the side of the box, new £700 or about £250 SH.
Any ideas where the connecting plug is as I would like to clean this up.
Thanks for suggestion on main gearbox plug will try to clean this at the same time. I assume it is at the rear of the box?
I have a n old JTIS that covers 2003 but it is damn difficult to find anything and seems blank on the rotary. Some info seems to say different part on 6 speed to 5 spee,l d some it is the same?

I am not impressed by Jag parts prices.

[Astromorg]

Your garage has got this wrong! The six speed box does not have a rotary switch. That's on the earlier five speed box.
You have a linear switch called the Transmission Control Switch in JTIS for MY2003. Adjustment of this switch is covereed in the Auto Transmission External Controls section under General Procedures. There's a bit about how it works in the Description and Operation Section.
JTIS thinks that to get full access you have to remove the selector lever assembly from the top of the J Gate, but it may depend on the size of your hands! The centre console has to be removed but that is easy and quick. Details in JTIS again!

Do you happen to know what codes were picked up by the garage?

New OEM linear switch from SNG Barratt £206 inc VAT. Maybe things are looking up!

[chrisipj]

Thanks for the reply. You confirmed what I had been thinking. Have emailed garage and waiting a reply.
The selector cable at the gearbox end is solid no loose bolts. Whilst I can touch the gearbox electrical connector there is no way I would dare to try and remove it with the very limited space. I assume it may require the removal of the rear gearbox support.
Moving the linear switch does not affect the light display on the j gate the correct light continues to display (flashing) however I move the switch