Hi there. Hoping this is an easy fix? Just bought 3.0 D'S 2003. Some days speedo works at first then stops mid journey. If its off when starting it hasnt come on mid journey. Hoping it's a loose connection somewhere but no clue where to start looking. Any help appreciated


Thank you.

 

It sound like the gear at the unit that turn the the needle at instrument cluster has striped half way.

 

Here's one post on a help fix-it site =

What could cause a Jaguar speedometer needle to fluctuate and stop on zero?

First, check if the speed sensor is working fine. Place a meter across its pins and measure the level of resistance inside the circuit. If it reads between 200-300 ohms, it will point to an open circuit that will need replacing. However, if it appears good, verify if the interface module for the sensor reads 12 volts. If so, the problem could be with the gauge. Cleaning up the contacts at the printed circuit board inside the gauge should fix the issue.

 

Also check the plug on the transmission/gearbox and clean it, look for worn spots on cable.

Last thought try this posted a while ago by a member =
a gentle reminder for all of us whose memories need lubricating from time to time. Using the Trip button press while turning ignition on (but not starting), we can enter what is known as ETM mode (read for full listing in FAQs here). Now, all soon learn and remember that you can read DTCs here ... and not just the generic, but also the body/chassis remote module codes. What we forget is there is much more ... including a nifty test routine for all gauges in the instrument cluster.

Aha, I hear you say ... there is a point to all this. Yes, this is purely a ballistic test but using a driver that is divorced from the normal speed sensor Stu has referred to. Comparing the gauge behaviour will show whether your erratic gauge has an internal fault or external sensor or sensor lead fault

 

All, the speedo is electronically controlled by the ECU. It looks at the wheel speed sensors on each wheel, averages the readings and then tells the instrument cluster where to put the needle. In the case of a single wheel speed sensor failure, the computer will ignore the bad sensor (giving the error code) and then average the remaining 3. When you have 2 wheel speed sensors that are bad, the computer does not know which ones are good and which ones are bad. Therefore the computer will make the speedo read 0 to give the driver the indication that there is a problem.

I would say to get the codes read for the car and see if you are getting a C1145, C1155, C1165, and/or C1175. These are the wheel speed sensor errors. We can then go from there.

If I had to take a guess, both of your rear wheel speed sensors have issues (a common issue).

 

Thank you! Got a problem with handbrake too so hoping all points to that area. Thank you to all other replies too. I'll post back if sorted 😁

 

Thermo has a post on testing the handbrake problem. Just search his posts, very clear and concise.

 

Where can I find thermos hand brake thread?

 

Found I had 3/4 ABS sensors out! Mate had a diagnostic tool 😉 fitted both rears easily enough however the front one is now snapped off after trying to wiggle it loose!! However now got a working speedo. Just need to figure out how to get the broken sensor out. Got too dark tonight 😥😥