To better assist you if you need to get back with me please let me know if your vehicle is just an XJ6 or a Vanden Plas. Also, the size of your engine in liter.
Your vehicle has a shift interlock system like you suggested. The transmission is equipped with shift interlock system. Shift lock system prevents gearshift lever movement from Park position unless brake pedal is depressed and ignition is on (position II). System also prevents ignition switch from being placed in LOCK position unless gearshift lever is in Park position.
You also have a gearshift interlock relay. I have attached that pic and location.
The interlock may be the Gear Shift Interlock Solenoid located in center console, at base of shift lever assembly.
It may also be according to the wiring diagrams, there is a micro switch sitting there also. I have attached that pic. That same pic (there are two you need to splice together - the switches are at the bottom) is the brake switch that also plays a part in this.
You might also please go to Auto Zone (AZ) or O'Reilly's (OR) and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don't get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery and alternator.
I suggest this just in case your car did throw a code this will give us more to go on. Plus with the winter weather it is good to know your battery/alternator are working strong.
It doesn't show any checks other than chasing wires for bad grounds etc but at this time I cannot locate pin voltage etc.
If it were me.....I would first take the console apart so I could see the switches there and see if there is any problem there. Even put my foot on the brake and see how it responds to see if it is hitting the switch correctly.
Check the switch at the brake also and see if it is out of adjustment. Put a meter on the wire at the micro switch (not the black wire) and depress the brake and see if you are getting voltage to the switch. If not then I would then replace the relay.....and check again.
If still no voltage then replace the brake switch.
If you are getting voltage to the micro switch at the shifter, then that switch may be your problem.
Monday, February 2nd, 2009 AT 5:28 PM