1993 XJ6 immobilizer security reset
 

Hello. I'm new to the forum and have owned my '93 XJ6 sedan with automatic transmission for 21 years near Cleveland Ohio. It has 89,800 miles on it and I drive it about once a week and never in snow or rain. I'm selling it to my 29 year-old son, so last weekend he drove it out of my garage and turned it off in the driveway.

A half hour later I was showing him the fog light switches while he was in the drivers seat and he wanted me to see if the lights worked. None of them came on, so I told him I thought the engine had to be running. He went to start the car and it was dead - no cranking could be heard and no movement of the gauges and the gear shift lever could not be moved and I suspected the security system had immobilized it. I have had the security alarm switch in the console set to off for many years and have never had an immobilizer problem.

I bought a new Duracell car battery to eliminate the battery as the problem and later fully charged it. I also bought new batteries for the remotes; they had been dead for years (I had used the key to unlock and lock for years). With the new battery installed and the remotes working properly to lock and unlock the doors, it still has the no cranking, no gauge movement when turning the key all the way. To be exact, the car can be locked and unlocked with the remotes or the keys, and the inside lights will come on and as soon as the key is turned all the way to start, nothing happens and the lights go out. Pressing the remote will make the lights come on again. I do hear what I believe is the fuel pump priming when the key is in the "II" position.

I have searched this forum and the internet for answers and can't find a solution to how to reset the immobilizer and the security system. I disconnected the battery and clamped the leads together for several hours; that didn't work. I locked and unlocked the driver's door and passenger door with the keys and that didn't work either.

Does anybody know of a solution I could try? I thought about pulling the security system fuse from the fuse box but it has a hard plastic covering on the fuse.

I appreciate any help. Thanks, J Shep

Wrong forum but I am fairly sure the problem is power-related.

Probably not immo as well, but can't rule it out.

Welcome to the forums 93jag,

I've moved your question from General Tech Help to XJ40 forum. Members here with the same model will be able to help.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

Hi J Shep,

Welcome to the Jaguar Forums! It's great to have you with us!

I owned a '93 XJ40 (the Jaguar factory project code for your car) for over 16 years and absolutely loved it. But in all that time, I never had trouble with the "immobilizer" system. To my knowledge, the security system is an alarm only and is not tied into immobilization, but I may be wrong. There is an inertia switch in the left corner of the driver's footwell, and in the event of a collision, the switch will trip and shut off the fuel pump, unlock the doors, and possibly activate or deactivate other circuits. I doubt this is your problem, but it's easy to check the switch. If I recall it's a small black plastic box with a red or black plunger-type switch on top that pops up if the switch has been activated. Simply press the plunger back down until it clicks to reset the switch.

My first guess regarding the cause of your problem is that the gear selector lever is not fully seated in the Park position, or the Park/Neutral switch is acting up. Try wiggling the gear shift lever and then firmly pressing it into the Park position. If that doesn't help, turn the key to position II (ON) and pull the lever down to Neutral and try again.

Another possibility is that due to low battery voltage the starter gear wedged against the ring gear on the flex plate and now cannot move. This happened several times on our '93. You can use a long socket extension or other suitably long tool to tap on the starter solenoid and motor housing. Often you'll hear the gear retract from the ring gear with a clunk. Just take care when tapping on the starter to not let your tool come into contact with the electrical connections on the forward end of the starter - the battery voltage wire is always live, even with no key in the ignition.

I have to run but try those ideas first and if they don't work we'll have more ideas for you to try.

Cheers,

Don

Thanks Don, I checked the inertia switch and the plunger was down where it should be. I tried wiggling the gear shift out of park and it will not move at all and still would not start, so I can't move it to neutral. Here are some more clues: when I unlock the door with the key or the remote and open the door, the interior lights come on and when I turn the key to position II, the instrument panel remains dark, the gauges do not move, the odometer does not come on, the radio does not turn on, and the fans will not turn on. Then when the key is turned to start, the interior lights go out and there is no cranking of the starter. When the key is released, the interior lights will not come on until the car is locked and unlocked.

What would cause all the accessories to not come on when the key is in position II and also have no start with no cranking of the starter when the key is in the start position and also lock the shift lever in park?

By the way, my owners manual for the 93 jag says the security system can immobilise the car. However, from reading other posts, people believe the immobiliser is not installed in all jags going to certain countries. My left side fuse box has a covering over the fuse (with no fuse) in the location labeled "security ECU" so maybe this means my jag does not have an immobiliser.

J Shep

Hi J Shep,

I'm in a rush and can't ponder all of your symptoms, but I have a faint memory of having similar problems when one fuse blew - possibly the fuse for the cigar lighter. I think that fuse is in the center fuse box but I may be wrong. Check those 10 fuses and see if one is blown.

Cheers,

Don

I checked all fuses on the left side and right side and console and none are blown, I pulled the cigar lighter fuse and with a volt meter, touched a probe to the fuse socket and the other probe to ground and it showed over 12.6 volts. With the fuse back in, there is zero volts going to the cigar lighter.

Same situation with the inside lights fuse and the door lock fuse: the fuse is not blown, and there is over 12.6 volts at the fuse box, but the inside lights do not come on and the door locks do not all unlock or lock with turning the key in the door or pressing the remotes.

So I have a car with a fully charged battery, no blown fuses, power going to the fuse box, but no inside lights, no working cigar lighter, no electrically controlled door locks, and when the ignition key is turned to position II, no instrument gauge movement and no instruments idiot lights, and no radio. The fan does turn on. When the key is turned to start there is no cranking of the starter whether it is in park or neutral.

What would make all these circuits not work at the same time? Everything was working fine a few weeks ago.

J Shep

I haven't had those symptoms but I do know the relay module DBC10008 is prone to failure due to cold or cracked solder joints.

It can be opened up and the solder re-flowed on the circuit board. This module controls the starter solenoid so it could be the issue - not positive about the module having a problem, but maybe worth a shot?

also check out this old thread that eventually gets to that module in a no crank issue ..

https://www.jaguarforums.com/forum/x...s-40464/page2/

good luck

Larry