Hi Everyone, a long time lurker. After about 10 years or so, I've finally gotten myself into a situation that I'm unable to diagnose with existing forum solutions. I'd be very grateful to secure some help here.

About the vehicle. I have a 2006 , non-CATS, naturally aspirated 4.2 (V8) Jaguar, automatic, S-Type with 132,000 miles. As far as I know, no maintenance has been completed on the "sealed" transmission. Although I'm fully aware of the process behind replacing the pan with the built in filter. I've never had any indication of a transmission problem. No lurching, or harsh shifting. I'm suspecting that I'm chasing an electrical issue.

A few things to note:

1. There are no CELs and no codes from the my ELM327 code reader.
2. The battery is a bosch, and was recently replaced and is holding proper voltage.
3. When inserting the key, and turning to the ON position, the car displays the "gearbox Fault" message.
4. The gearbox selector is not illuminated. In other words, the "P" in the j-gate selector doesn't illuminate red like It usually does.
5. When stepping on the brake, I don't hear a click, BUT I can't remember if this car does that or not. (Hoping to get confirmation from others)
6. When turning the key selector to start the car, the engine does not crank, all I get is a chime. I.E. No crank condition, and it simply doesn't turn over.

I've spent time investigating the 2006 S-Type Electrical guide found here:

http://www.jagrepair.com/images/Auto...cal-2006on.pdf

Per the schematics I've inspected fuses:

F2
F15
F33

Unfortunately, they all appear to have connectivity.

I've also identified a capacitor in figure 04.1 between P-159-1 and P-159-2 (you can search the PDF). I'm wondering if this capacitor has gone bad, but I'm unable to identify where this capacitor is. Does anyone have an idea where that might be located? From what I've been able to gather It seems to be in GB2, and I hope it isn't because it appears to be inside of the transmission, and I'm hoping to get some clarification on that too.

At this point, I feel like I'm chasing a ghost. Does anyone have any ideas on where I should start focusing my efforts?

Looking forward to your thoughts!

 

I wanted to add that an additional message “Cruise Not Available” is also being displayed on the DIC.

Any ideas?

 

One possibility is where the gear shift cable is bolted to the trans side (see under the car). Two 8mm hex bolts which are notorious for coming loose or falling out!

 

You could pull off the jgate trim bezel and have a look....maybe something out of place under there....at least make nothing has come loose

 

Even if the cable was disconnected, wouldn't the indication on the J-gate bezel still light up as normal? I'd think you'd still have the indication (P, R, N, D, etc.) for whatever gear the transmission was in.

 

It can be between gears but in any case does the TCM send the packet to the J-Gate to display the gear or if not, what does? Maybe they can disagree and you see one gear but some other parts of the car think it's another.

It's easier to check the bolts than discuss it and they need checking at least annually - or add thread lock if you wish.

 

If you have a Gearbox Fault message, I'm almost positive there should be a corresponding fault code stored. Your ELM327 reader may be a generic version and is not able to access some Jaguar-specific codes. Can't guarantee this, but it may be worthwhile to consider an upgrade. For example, I had a Gearbox Fault last year on my '02, and had a corresponding code of P0745, IIRC. This led me straight to the fault, a bad shift solenoid in my case. Without such data, you're flying blind, which can be an expensive proposition when troubleshooting

Excellent troubleshooting so far, and thanks for posting all of the little details you have observed. The lack of the indicator lights is very unusual. Are you able to move the lever out of P, or it locked? If you can move the lever, do the other positions illuminate?

The lack of indicator lights makes me wonder if the problem is something as simple as a connector worked loose. I'd remove the console around the shifter and check those connections first, just because I'm lazy. After that, you'd have to raise the car on jack stands and check the connector at the transmission. Physically inspect the connectors for condition and security, and also for voltage and ground per the wiring diagrams.

The capacitor you mentioned? If shorted across, that might cause the symptoms you're seeing. No specific location is listed in the wiring diagrams, but I bet it's wrapped inside the harness, close to the transmission connector.

This recent thread may be of some interest. Some of the same symptoms, although the engine would start. The root cause was the wiring harness rubbing to ground near the transmission. The harness included plugs for the V6 and V8 versions. The unused branch was where the damage was located:

https://www.jaguarforums.com/forum/s...rmance-222582/

 

hmm, P0745 is not Jag-specific and should definitely show in all OBD II tools, including an elm327.

Any internal gearbox codes which are not generic OBD ones can be read by an elm327 - except no-one appears to have written the software needed to fetch them from the TCM via the elm327.

edit: this is about the 2002.5MY/2003MY-on cars as the earlier cars have no separate TCM

 

I believe that the electrical signal at illuminates the gear indicators in the selector quadrant originates inside of the transmission; so, a check of the attachment bolts for the linkage cable as a first step appears to be a logical first step in troubleshooting...

 

Hmmmm...

Here are the ODB codes for 2003+ cars:

http://www.jagrepair.com/images/Auto..._OBD_II_R2.pdf

The transmission codes run primarily from P0605 to P0860, although there are a few others outside that range. Note the second column labeled SYS. See page 2 for a description of this column. The top line indicates which computer is reporting the fault. The second line indicates whether this code is generic (OBD II) or Jaguar-specific (JAG).

This column should give you an idea of how many Jaguar-specific transmission codes there are. I was hoping to find one that would inhibit the starter operation, but I haven't found one yet.

 

By definition (well, law as well) a P0 code cannot be make-specific (and Jaguar do follow the law).

To be Jaguar-specific a code would need to start with P1.

 

Hope this wasn't a drive-by. No word from the OP after 3 days...

Found this older thread, see post #2 for an explanation of where the P, R, N, D indicators get their signal to illuminate. Because those indicators won't illuminate, this seems like the best place to investigate in hope of a fix:

https://www.jaguarforums.com/forum/s...-usual-184878/


Please note that thread discusses both the early and late models, so not everything is applicable to all years. On the 6 speed models (2003+), the P, R, N, and D indications are feedback originating at the transmission. But the feedback for the left side of the shifter originates in the J-gate assembly. That's why I was asking if it's possible to shift out of Park and try all other positions. If none of the positions will illuminate, that would likely point to the J-gate assembly.

Found this thread, too. Although the engine would start, the lever wouldn't shift out of Park. More importantly, the P indicator wouldn't illuminate, which is unusual. He also had a U series code, but unfortunately there seems to have been a typo so we don't know the exact one:

https://www.jaguarforums.com/forum/s...solved-150615/


In that unusual case, where the P indicator was inop, the fix was to clean some "caramelized fuzz" from the circuit board inside the J-gate assembly. That would certainly be worth investigating. If you don't want to spring for a scanner that can read the Jaguar-specific codes, it might be worth gambling on a used J-gate assembly from eBay.

Also note that link contained a video showing how to override the park interlock. If you can do this, you can shift out of park and see if any of the other indicator lights are working.

 

@JagV8 Thank you for your suggestion here, and I appreciate your patience. I’ve been tied up on a business trip. Just now getting back. Regarding those bolts, I’ve checked them both and they’re both very secure!

I did want to mention that I did follow the instructions to physically put the car in gear by turning the little knob on the bottom right (driver side) of the gearbox selector, none of the lights would illuminate as I moved through the gears. I also tried starting the vehicle in the N position. Again - no dice.

Thinking about the j-gate, I do remember that I did move the gear selector to the 2 position and back to the D position, but I can’t remember if my issue started soon after taking the gear selector all the way around the j-gate. 🤔

 

Howdy @kr98664 !

Regarding the j-gate, yes it’s definitely locked without illumination; even in the other positions. I had to take apart the entire console to remove the j-gate so that I could access the bypass to get it into neutral and roll it into my garage.

The other thing that I could mention is that I took apart the entire cabin filter assembly to ensure all of those connections were dry. Those were all in great shape, and there were no signs of water. I had read a post that water intrusion near the cabin filter was cause for similar symptoms, but I didn’t see any signs of water so I moved on.

I’ve got the car way up on stands, I’ll move under to see if I can get a better visual on those connectors. I wonder where that alternate pigtail is located. Do you know if it’s in the cabin? Or under the car? I don’t have a ton of experience testing voltages. I’ll have to head over to YouTube for a refresher.

Thanks for all of your guidance here! Much appreciated!

 

@S-Type Owner What points you to that belief? I’m hoping to not tear too deep into the tranny. Yikes!

While doing so research I did come across this the following video when seeking information on the “Gear Box Fault”:

Transmission Fault ZF BMW Jaguar Range Rover Land rover

 

@kr98664 Hmm, this maybe the jackpot!

i don’t have illumination on either side of the J-gate. 🤔

Is there a secret to getting the JV ate out of the center console? I can’t seem to find a way to disconnect the cable.

 

I may have missed it but did you check the 2 bolts (post 3) yet and are they OK?

 

My best guess is this unused plug is located close to the transmission. The harness probably splits near the end. The unused branch is probably folded back and taped over, but I don't really know.

 

Here's an image stolen from eBay. The cable end has a socket that snaps over the protruding stud, highlighted with an arrow. Working from above, you should be able to pop the cable off to the side using a long screwdriver or similar tool.

 

Here's a more appropriate video for you to watch:



That first video you found? About the only thing in common is that car also had a transmission and it just happened to be a similar ZF model as your car. His symptoms were TOTALLY different from yours. Note he kept talking about starting the engine and shifting back and forth. On your car, the starter is completely inhibited and the lever is locked in Park. Not even close...