"GEARBOX FAILURE". Sigh...





Having avoided it now for several days, this morning I plugged a diagnostic scanner into poor Nanny, my old Jag. And - trust me - she set a new record for whining and complaints (22 fault codes).

Befitting her British heritage (all good BBC whodunits feature a vintage Jag or two), I began badgering about for suspects. It would be justice served, or an ignoble retirement for Nanny as a British Racing Green backyard flower planter.

First was an interview with the dimwit driver...
"It was roughly 6:00 AM, dark and stormy - rain pelting, heading south out of the Blue Ridge mountains. First, the (adaptive) cruise control quit - followed shortly after by an "ABS Warning" - and, nearing 7:00 AM, the "Check Engine" light flashed on. When I finally arrived in Oriental, North Carolina - a 250 mile voyage (for dental work) - Nanny's dash was lit up like Christmas. Warning lights still on, the return drive seemed uneventful, until I stopped for gas nearing home. Leaving the station, Nanny's engine roared and the transmission crashed and banged - a flashing dash screaming "Gearbox Failure". Finally, the transmission lurched into third and stuck there, engine racing at 40 MPH. Feeling pretty lucky to have made it this far, I limped home with the engine roaring, finally turning in the drive around 6:00PM."

Intrigued by the crime sequence, I noted a "C0037-07/int" on the lengthy rap sheet: "LR Wheel Sensor/intermittent". Could this have triggered a cascading sequence of faults, culminating in "Gearbox Failure"?

Erasing all the codes, Nanny magically turned from ugly pumpkin to beautiful princess again - no dash lights/warnings, and the usual smooth. powerful driving performance. Puzzled. I looked at "Wheel Sensor Live Data" on the scanner, but all seemed OK at the LR corner.

Hmmmm...I pondered. "Dark and Stormy - rain pelting..." That would mean wet. So, I pulled the LR wheel and had a look. See the pics below...
- Reluctor (toothed ring) has a shiny spot - something rubbing
- ABS Sensor has corresponding damage; exposed windings...pebble was ejected

So, dear Inspector, here's how I imagine the crime scene:
Pebble jammed between the reluctor ring and sensor at some point, damaging the sensor. Rain eventually wet the windings, shorting them and switching off cruise control, progressively throwing ABS fault, etc, etc, until "Gearbox Failure" warning, etc.

A new "xr822753 Wheel Sensor" from Spaceship JLR, Ltd is $259.00, plus shipping. I ordered a pair of Amazon knockoff's for about $30. Should be here in a few days...

 

Prior to replacing any other parts that are not damaged, determine the battery voltage across the terminals with a voltmeter. Quite often random DTCs and other instrument cluster warnings are the result of failing or weak battery.

With the ignition in the OFF position, the voltage across the battery terminals should show at least 12.6 volts on the voltmeter. If not, charge the battery for five hours at 2 to 5 amps and retest again. If the voltage is still less than 12.6 volts, the battery is suspect and must be replaced.

 

Based on the appearance of the rear brake pads in the third photo, they too should soon be replaced.

 

Battery is fine; as are the pads. Its the ABS sensor at fault, I believe.

(I have had weak battery issues with this and other cars, and at the time wondered whether the alternator was failing during my long drive - causing all the dash warning lights, etc. But, its fine also)

 

What is the battery voltage?

 

The Jaguar price is ridiculous !! I had to replace one once and got one on the internet for not much money at all. It was probably an OEM and was made in Germany.
Here's eBay
https://www.ebay.co.uk/sch/i.html?_n...waAmExEALw_wcB

 

Thanks, Fraser
Yeah,the ones I ordered are probably Chicom, but I've used similar in my M3 BMW with good luck. Seems most of the electronic bits in my '07 Jag are actually ND (Nippon Denso; Japanese). Even these (eg, O2 sensors) can be found for a fraction of JLR prices...

 

Looks as if I'm not the Lone Ranger:

Old 12-31-2016, 07:41 AM
Ed davies
Ed davies is offline
Default Had the same issue now solvedI 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.

 

I'm glad I bought a code reader, because it told me straightaway what sensor had failed, so I could order the correct part and then jack up the correct side of the car.

 

The idea that a dinged/wet wheel sensor could have the car in gearbox failure limp mode is a little disconcerting.
I regularly drive this old Jag back and forth across the country; its a superb long distance travel companion. Hate to have something like this happen in Bushytail, USA.
(And, I'm morally certain that the problem might have been diagnosed as a bad transmission by most repair shops - 15 TCM codes, of the 22 logged during my drive)

My OBD scanner (Foxwell 510) will now live in the XJR glovebox...

 

The transmission gets the vehicle speed from those sensors. If it does not know how fast you are going it triggers limp home mode to try and protect itself. It apparently does not understand it has just lost the vehicle speed and thinks either it ir its TCM also has a problem.
Also the vehicle speed is used for the keep alive signal for most of the other modules. If they do not see it they go into default mode and wait for it to return. Even the radio will not be happy since it looks at the vehicle speed to increase volume as the speed increases.

 

I'm the same hisport, I keep my Foxwell NT644 in the jag, I never believe the dash, soon as any faults pop up, I plug the reader in read over the codes, then clear them and off I go, if they stay gone, I'm a happy bunny, if the pop back up, then I have to investigate.
I have also had the rear speed sensor go, didn't get as many codes as you, but couldn't believe how easy it was to swap it out, popped it on a 4 poster, and had it changed in under 5 mins without even removing the wheel, Some cars, it's an adventrue changing sensors, half the car dismantled and on the floor gas burners, pillar drills, some of those little buggers just do not want to come out.

 

Quick Update:

- I installed the new ~ $15 ABS sensor today, and all seems well
- Coincidentally, I will be repeating, next Tuesday, the same 500 mile round trip which ended in "Gearbox Failure" two weeks ago. Keeping fingers crossed...
- Regarding the "Whys", my schoolboy look at things shows that the primary VSS (vehicle speed sensor) seems to be in the transmission, measuring tailshaft RPM. While I gather that Nanny got her panties in a twist when VSS data no longer corresponded to the LR wheel speed data (due to bad ABS sensor), just how this could have generated a "Gearbox Failure" hissy fit puzzles me
- Yes, mercifully, the Jag ABS sensors are easily renewed. (I replaced the ABS sensors on my E46 M3 BMW recently and it was a nightmarish job - just as Brian says - lots of disassembly to drill out frozen fastners and seized sensors)

 

that’s how many modern cars are set up. it compares output shaft (VSS) data to wheel speed data, if it doesn’t match it thinks the transmission is slipping and throws an incorrect gear ratio code and goes into gearbox fault mode. this is why you can’t change rear end ratio.

on the 308 SC with the mercedes transmission it shifts based on VSS data but periodically runs checks, I could get about 20 minutes before having to clear the code again.

 

It's prob more likely to be connected to the traction control system, which, I think, uses signals from the rear wheel sensors and the gearbox, to decie if the wheels are slipping and traction control should be applied, so basically, if the gearbox is saying, "yeah, I'm traveling at 50 mph", and the RH wheel sensor says, "me too", but the LR wheel sensor says, " I'm not turning at all", or "I'm at 250mph", then the control units sh*t themselves and think something major has gone **** up, and all hell breaks loose.

 

Hi thanks for writing the information about rear wheel sensors & gear box faults, this has just happened to me on my xj8 2003 , I am going through the process and hoping that I am as lucky as you, I will update once I get the parts & fit, thanks, kind regards Ernest.

 

Best wishes, Ernest!

 

Presuming you joined only after buying the 2003 X350, didn't have it 'force you' to make your first post for a full ten years?

Unless.. you have gone through SEVERAL Jaguars in between?

Drive a used Jaguar mostly trouble-free for ten whole years before the Devil and his Service Department even twig to you owning one atall?

Looks as if the usual luck of the Men of Harlech has worked right well for your patient self!!!

 

My Abs/ gearbox fault was just the offside rear sensor, tried a cheaper sensor but had to get a better quality sensor, then all faults disappeared , I originally over thought it though , thinking the reluctor wheel out of shape/Rusty , but the other side the same ! , so checked I had 12v at the sensor connectors 😀 I am a vehicle technician, but work on HGV so mostly when issues occur I just get on with it ,so not into posting on “ normal wear & tear issues “ but found this site helpful.
Thanks, regards Ernie