Hello All,

I have a 2004 X350 Super V8 LWB, The problem is, when the car starts, for the first couple of miles the car will be incredible jerky and consantly jerk, eventually the dashboard will light up "Gearbox Fault" and the car went into limp mode and all would be fine from then, the gearbox was smooth.

I bought a Mongoose with the SDD software from eBay and loaded it onto my pc, I ran the software and looked at the fault codes on the car, the ones relating to the gearbox were:-
P0783 - Gear load 3-4
P0735 - Gear 5 Incorrect Ratio
P0736 - Reverse Incorrect Ratio

I was advised to "reflash" the box, so using the Mongoose I ran the "Transmission module adaptaions clear" and cleared all the fault codes, after this I took the car out for a test drive but it began jerking and went into safe mode less than a mile into the journey, did I do something wrong? Is there a different way to reflash the box?

Also, I have already had the gearbox fluid refilled.

 

Hi JaguarLover101,

According to the DTC Summaries, the possible causes of all three of your transmission codes are:

ECM Torque signal fault, or
Transmission mechanical failure

You can download the full-length DTC Summaries manual here:

https://www.google.com/url?sa=t&rct=...03388427,d.cWw


If there were other DTCs stored it might be helpful to know what they were, since they might give us a clue as to whether the problem is electrical or mechanical.

You can download the 2004 XJ Electrical Guide here:

http://www.jagrepair.com/images/Elec...al%20Guide.pdf

If I read the guide correctly, the ECM (Engine Control Module) Torque Signal is transmitted to the TCM (Transmission Control Module) via the CAN (Controller Area Network), so if any of the other codes you had were CAN related, that might be a clue.

A few things that might be worth checking:

1. The transmission fluid level. It must be checked per the instructions in the Workshop Manual (car level, transmission at the correct temperature, etc.).

2. The electrical connector on the transmission. The sleeve around the connector is known to leak and allow transmission fluid into the connector, which could interfere with the electrical signals to the TCM. If the sleeve was not replaced when your fluid was changed, it would be suspect.

3. The electrical connector at the ECM, which is under the cabin microfilter housing in the right rear engine compartment. Disconnecting the connector requires a 5-point security Torx bit (with a hole in the center). The drain under the filter housing is known to become clogged with leaves and seeds, causing rainwater to pool around the ECM connector.

4. I can't recall for certain on the X350, but I think the ECM references the MAFS and/or CKPS signals in calculating engine torque, so it might be worth cleaning the electrical connectors for those sensors with zero-residue contact cleaner spray. While you're there, you might as well clean the interior of the MAFS/IATS with the same spray or special MAFS cleaner spray.

In the meantime, it seems prudent that you should assume the transmission has mechanical damage and should not be driven until it is repaired. Otherwise, you risk causing far more serious damage.

Please let us know what the other codes were if you can.

Don

 

These are the other fault codes, reverse is not on there as it is under "Related Symptoms", the only one, after selecting "Gearbox in limp home mode"

 

JaguarLover101,

I can't quite read all the codes no matter how much I enlarge them. Could you please try snipping only the area with the codes and reposting them?

Cheers,

Don

 

Sorry about that, here they are enlarged

 

That's better!

When we see a long list of DTCs like this, the first thing we suspect is low battery voltage, especially while cranking the engine to start. I don't think that is the cause of your transmission performance issue, but Jags don't like low voltage. I would recommend that you have the battery load tested, and have the voltage read while cranking the engine. If the battery is fairly new, the problem may be excessive resistance in the battery power and ground circuits due to corrosion on the connections throughout the car.

But first, there are a few things you can try to see if your transmission jerkiness improves.

The B2139 code is curious. It indicates that the ECM identification does not match the Instrument Pack/Cluster. My first assumption would be an electrical problem in the ECM/IP circuit, either corrosion on or looseness of a connector, or corrosion on an associated ground point. Since the IC provides the speed signal for the transmission, this could be related to your problem. The most likely culprit would be the ECM connector since it is more likely to be exposed to water.

B2162 is related to the security system, but also has to do with the IP. If either the B2139 or B2162 codes are shown as intermittent (broken chain link with "rays"). If either of these codes was permanent, the DTC manual indicates your engine would not start.

My impression is that those codes are probably glitches due either to low battery voltage, connector or ground corrosion, or both.

The P1582 code indicates that flight recorder data is stored because any of five events occurred: Inertia Switch activated, Throttle Limp Home Mode activated, Engine started and stumbled, Engine failed to start, or Engine stalled. Of those, Throttle Limp Home Mode could very well be related to transmission issues. The solid chain link indicates this is a permanent code. It would be worth carefully checking the electrical connector on the Throttle Position Sensor (TPS) for looseness or corrosion or oil contamination on the terminals. I mention doing this carefully because some members have reported the TPS electrical connector deteriorating and crumbling when handled. At least one member found wire ties holding his connector together, apparently installed by the previous owner. If you can disconnect the connector, flush the pins in the connector and on the TPS with zero-residue contact cleaner spray, allow to dry, then carefully reconnect.

I still think the things I suggested in my previous post will be worthwhile.

C2302 is one of the codes associated with an air leak in the air suspension, or the air compressor failing to repressurize the system in the alloted amount of time (120 seconds). I and many other members have resolved this code by replacing the piston ring/seal in the compressor with a new ring from bagpipingandy.com. If you can resolve your transmission problems, that might be your next project.

Once you've cleaned the transmission, ECM and TPS connectors, clear all the DTCs and see if the car runs any better. If not, see which DTCs have reappeared. At that point I would recommend checking the transmission fluid level following the Workshop Manual instructions.

Please keep us informed,

Cheers,

Don

 

I have had my XJ8 for about a year and lived with a transmission issue for way longer than I should have. Some pointers from my experience:
1. When my cat went into limp mode after the gearbox fault light, it definitely didn't smooth out. It got stuck in one gear. Your results may vary, but please watch your RPMs for the sake of the mechanical bits of the transmission.

3. Did you take it to an independent or jag dealer to refill the fluid?

2. I can't confirm whether that is the correct way to reflash it, however I can tell you that the dealership surely knows how to reflash it if applicable. After spending a good chunk of a weekend researching replacement gearboxes, zip kits, acceptable substitute fluids, driving in manual mode etc., I finally bit the bullet and took it to the dealer. Now, I normally prefer to work on my car by myself, but for the cost of 1 hour diagnosis, they checked my fluid, and performed TSB JTB00072 after confirming it exhibited the symptoms. I let them keep the car for 2 days and I don't regret it.

I would recommend taking it to a jag dealer for a proper diagnosis then decide.
Regards

 

I really would get battery (and its connections) checked, it seems stupid but even a slightly voltage can throw up all sorts of of errors.

 

When using SDD I would suggest using a 40A battery maintainer, this overcomes any drop in load on the battery whilst the SDD carries out any checks and possibly alleviates any low battery issues showing up in your results.

A simple maintainer can be purchased for $30. https://www.jaguarforums.com/forum/x...tainer-149395/

 

I know this is an old post but in case anyone has the same issue. The problem on my 2003 xj was the rear passenger side ABS/wheel speed sensor, It was sending the wrong signal to the gearbox ECU this was throwing up a gearbox failure warning, replaced the said sensor and all sorted.

 

So Jag Lover,

What did you get figured out? The world wonders.

 

Don't ya, just love when a poster sucks around for information and you never hear the final result...Loser...

 

Not sure that makes him a loser. He could be busy or maybe sold his Jaguar. He hasn't been online since July and if he was, I'm not sure insulting him is the best way to extract information.

 

Just in case others have shifting issues, it can also be caused by bad sparkplugs and associated coils, even without misfire codes.

 

I thought I had updated, evidentally not.

Incase your still interested, or for the benefit of anyone who comes across this thread. The fault was diagnosed as an internal solenoid fault by a gearbox specialist, so I took it to a Jaguar specialist who tried and failed to replace the solenoid, so in the end they swapped out the gearbox for a reconditioned one.

However now, it's just started leaking from the valley hose, so I've got some more fun on my hands

 

How many miles are on your car?

 

164k miles

Also, for the benefit of anyone coming across this thread, the way I mentioned before is not the way to reflash the gearbox, you have to do "Configure existing module: Transmission Control Module"

 

Could you please clarify where was that dead solenoid?
Because it seems to me that swapping the gearbox because of that solenoid is killing a fly with a hammer...

 

I handed the car to a trusted specialist, it may not have been a solenoid, but it was something that prevented the car from going into gear 4, I thought they said solenoid, but it could have been "It may be a solenoid" hence they tried and failed to replace

 

E Clutch