gearshift interlock solenoid
 

This all started when I pulled the j-gate apart to fix a broken bit ( not me!) The solenoid was operating fine before disassembly. I put the j-gate back together. No "click". Stuck in park. Pull it apart again. My interlock solenoid is now on the bench and tests perfectly. I have tested the voltage at the two pins in the connector that connects to the sol'd. (Paper clips are just the right diameter to get in the holes.) With the ign ON or OFF, I get 7.76V constant at the pins no matter what I do ! If I start the engine I get 8.3V. Punching the brakes does nothing ( I can see the brake lights come on so the switch is OK.) I switch the ign off and the 8.3V remains. The only way I can get "rid" of the 8.3 volts is to disconnect the battery. When I then reconnect the battery, it's back again. If anybody can tell me where to go next in this saga, I'd really appreciate the help. Do these computer modules use a "sensing voltage" or something ? When I read the "books" they seem to stress that "all components" need to be "connected" ..in which case how do you test anything ?Anyhow, with the solenoid removed, the car starts and runs perfect. (This is a RHD car and Oz law does not require the gearshift interlock. ) Any help appreciated. I rebuilt this car from a write-off wreck. This is my first play with a "computerised" Jag. This car has been "to hell & back" and apart from this small glitch, everything else is fine . Any help appreciated.

Just a SWAG but the brake switch is a double switch. One side is normally open, it operates the brake lights. The other side is normally closed for such things as the transmission interlock. But then, if the switch is not functioning properly you should be getting a check engine code.

Beyond that you are going to have to get the electrical schematic out. I will make the assumption that if you rebuilt the car you have a copy of JTIS. If not, it is available as a free down load on this forum.

Hi test point, I actually first posted this on the "replace brake switch" thread but got no responses ....so figured I was off-topic & started this thread , after many searches of the forum failed to tell me much.
https://www.jaguarforums.com/forum/x...ics-faq-37758/
Yes, I have the JTIS ( two versions) . I'm very familiar with the wiring schematics that come in the Electrical Guide but they aren't much help. If you read my post on the brake switch thread, according to the schematic it is the SAME contacts/connector terminal numbers/wire colors that operate the brake lights as operate the interlock solenoid. The other (normally closed) contacts operate the cruise control. Fig 05.2 (brake switch to solenoid) & 09.2 (brake switch to brake lights) refer. So I'm pretty sure the brake sw. is not the problem here. What I need to know is how the body processor module "talks" to the solenoid ( Fig 05.2). or if I'm wasting my time and need to get the car to "somebody" with one of the computers. I like to do stuff myself. How do I contact an expert on this forum ?

I'm having a problem with my transmission interlock as well so perhaps someone can help us out. I have a 97 XK8. At first the key would only only come out of the ignition every few uses. At the same time I had to use the manual interlock release to move the gear shifter to neutral to start as it would not start in park. The key now comes out of the ignition when turned off, but the car chimes the "not in park" sound even though it's in park and I can still only start the car in neutral.
Given what I'd seen in other posts I have replaced both the brake micro switch on the pedal ($80 from the dealer) and the "park" switch on the gear selector ($60).
No change. I do not hear that little click when applying the brakes.
My next step was going to be testing and replacing the interlock solenoid but I don't want to just keep throwing parts at it if it's not the real problem. Is there an easy way to test it in the car or must I take it out?
Seems like it may even be the body control module but how can that be tested?
I've checked all the fuses on both sides, and I also tightened the battery cables (at the battery) after doing a hard reset.
I also have a P1000 code in the system which seems like it is may be related to transmission issues?
Thanks in advance for your help.

Hi ATX. Both solenoids ( key & gearshift) are controlled by the body processor module. Fig 05.2 Electrical Guide refers. We need to know how these "talk" to each other.....

My quick look http://www.gusglikas.com/images/Auto.../jagxk1997.pdf Fig 5.2 gives you an overview of the wire and control for the interlock. From your post it sounds like you opened the area and closed it back and then is when you had the problem. If this is the case I would begin looking for a pinched cut wire and for this reason I would begin looking for a blown fuse. I hope this helps!

Hi Gus, Thanks. I have the 1997 Elecrical Guide (came as part of the JTIS download). Please see my very first post. I've checked the wiring to the sol'd. One wire is to ground and it's good. The "other" wire is "power" and it has voltage....but it's there all the time ! So that at least means the wire is continuous. The sol'd bench tests perfect. According to the wiring schematic 05.2, there's no fuse between the module and the sol'd. Next ?

Peter I am not sure I can help but I asked someone to look at your problem. Give it a little time I am sure he will respond, he loves a challenge.

Have you checked the 'not-in-park' microswitch? Does it cycle on and off properly when shifted in and out of park (assuming you have the gearshift lock solenoid disconnected).

Hi White XKR ...Yes. I think that micro-switch is OK. In as much as I get the "beep beep beep" if I try to take the shifter out of Park. Also, the brake light switch is OK as the brake lights work fine.

The eight or so volts you measured...is that the open circuit voltage without the solenoid plugged in? Have you measured the voltage with the solenoid plugged in?

That's the open circuit voltage. Solenoid is on the bench. To measure it I "poked" a paper clip into the connector (once I'd determined which was the ground pin and which was the power pin.) I can't see any easy way to measure the voltage once the connector is "plugged" into the sol'd. Only way I can see is to strip a section of wire .... which I was reluctant to do. Those wires are not like the old Jags. Not much "meat" to play with. Thanks for your help.

Peter,

Can I assume you found the problem?

The open circuit voltage is not teling you much. As you suspected, I believe it has a current sense capability to detect a failed solenoid and therefore the presence of a high impedance voltage when the circuit is disconencted. I strongly suspect the the voltage falls close to zero when the solenoid is connected and not activated, and close to 12 when activated.

Its seems as if this problem is not a big issue for you, but if you really want to track it down I think you need to check the continuity of the 'not in park' switch, thie ignition position II switch and the brake switch. I know you have inferred that these are OK, with without full knowledge of the logic in the vehicle a positive test is the only way to be sure. I believe that one of the switches or connectors are the most likely items to be failing or has become misaligned on reassembly.

WXKR .. Before I respond in full, do the modules/computers on these cars "know" and "remember" that a component (in this case the solenoid) has been removed ? ...or in my case, it would be exactly the same if the solenoid went open circuit / high impedance. Do I need a "scanner " to troubleshoot these issues ? Also, why doesn't it "correct itself" when I reconnect the (perfectly good) sol'd. The sol'd bench tests just fine, I have tried re-fitting it, disconnecting & reconnecting the battery, etc . No change. Still won't operate. Where can I read up on this? And yes ..the car starts and runs perfectly, no error messages on dash etc .. I don't intend to re-fit the interlock lever, but I could refit the solenoid ( so the electrical circuit is complete to "keep the computer happy") and simply omit the moving plunger and interlock lever. But I'm also interested in learning how all this "stuff" talks to each other. Once again, thanks very much.

Thanks for posting the link to the electrical guide Gus.
I haven't had a chance to test anything further on mine yet but my current status is that when I have the car in park, with the brake pedal pressed I can turn the key all the way and nothing happens (starter does not engage).
I then use the manual interlock release to move the car to neutral and I can start the car.
Once I put it back into park, it will not come out of park without the manual release. It also chimes the not in park sound, even though it's in park.
I replaced the brake micro switch and the not in park micro switch and nothing changed.
I was going to go after the solenoid next, but it doesn't sound like that is sure to be the issue.
Any thoughts? Thanks

Just waiting ..waiting .... waiting ..
 

Well, I'd hate for you guys to be buying drinks cause a man would die of thirst. What's a bloke got to do to get some help around here? :icon_hyper: I've been patient. I've emailed a moderator and asked for "heeelp". But, one day I'm going to be dead and I'd like to sort this out ...so ... for some completion .... I've removed the darned interlock solenoid, I'm driving the car with no error messages on the screen and no obvious problems. I've "buttoned up" the console so I can go and get my registration inspection. If somebody can help me with this problem, I'm here ready and waiting.

Well Peter, sorry, guess I dropped the ball on this one...its been pretty hectic lately....

Do the modules/computers on these cars "know" and "remember" that a component (in this case the solenoid) has been removed ?
In most cases they do, assuming the ignition is turned on.

Or in my case, it would be exactly the same if the solenoid went open circuit / high impedance.
Most likely

Do I need a "scanner " to troubleshoot these issues ?
They are in general extrememly helpful, but a 'generic' scanner (which can be had for less than $50) may or may not 'see' this problem. The next step up is an AutoEnginuity Scanner with the Jaguar option, and that is about $500 USD.

Where can I read up on this?
You already have JTIS. You have looked at the info on the solenoid already.


But I'm also interested in learning how all this "stuff" talks to each other. There is also section on fault codes and a section on the various communications busses in JTIS. This will give you a general idea of how the system works, but the detail you seek proabaly will not be there.

The system is designed to be diagnosed with the special Jaguar diagnostic equipment. The messaging protocol is proprietary and I do not know of a source for it without spending big $. In this thread https://www.jaguarforums.com/forum/x...ut-gear-54443/ Andy had dug into the protocol a bit with a special developer's diagnostic tool.

If I had the messaging protocol, or the time to decode it, the sky would be the limit for cool products from the TheJagWrangler.:icon_razz:

Thanks for the reply ...
 

Didn't mean to make it personal Wrangler , but thanks .....I'll take help from anyone ( bit like the gov't and taxes huh ?) As you assumed, the information in your post is pretty much known to me. The car is this week with a Jag guy who has the real-Mcoy Jaguar computer gear. He tells me if the car has any problems ( or secrets) they'll show up. So I'll report back when I have the car back. Right now, the gearshift interlock solenoid is "on the bench in my workshop" and the car is driving perfectly.

Peter,

I was reviewing your progress and saw that you took the car to the shop for evaluation. That bad? I looked to see if I was the moderator you attempted to reach but I did not see a thing.