Was driving my 2002 S-Type 4.0. Message display read CATS SYSTEM FAULT and DSC SYSTEM FAULT. BRAKE light and ABS light were on. Speedo was inop. No odometer reading. No check engine light.

Came home; scanned... only DTCs were P0500 Vehicle Speed Sensor Circuit Malfunction, and under Adaptive Dampening category... U1041 Vehicle Speed Signal Missing.

I didn't clear the DTCs.

Restarted... no errors displayed on cluster and the BRAKE and ABS lights weren't on... odometer reading was back.

Drove a bit... speedo was working... no error messages or warning lights.

Does this mean that it was an intermittent issue, and the errors are no longer occurring? Should I erase the DTCs and drive to see if the errors are displayed again?

 

Could be failing battery / bad power but perhaps more likely something not right with a speed sensor such as rust on one. You'd need the ABS codes, really.

I can't see any point in clearing the PCM (aka ECM) codes but if you do you also clear the OBD monitors and may regret that.

 

The faults you describe are usualy down to a faulty wheel speed sensor.
You just need to know what one to change.
I use the jaguar SDD software, but your 02 car is too old for that. Only the older Jaguar IDS software will work on your car.
I do not know what non-jaguar code readers, if any, will tell you what sensor is playing up. Others may well help you with this.

Before you ask, no, the wheel speed sensors can not be tested with a meter.

Mellow

 

Thanks for replies.

Reply to JagV8: I replaced battery 8 months ago. This one much better than last battery that would repeatedly go dead.

Reply to M-e-l-l-o-w: Initially, my scanner didn't show any DTCs under the ABS category.

Update... I didn't erase any codes. Took it for a drive. After couple miles, got CATS SYSTEM FAULT only, along with BRAKE and ABS lights. Brought home, shut down.

Next day, hooked up scanner. Once again P0500 under Powertrain category, and U1041 under Adaptive Dampening category. No ABS codes.

Left scanner plugged in to read ABS wheel sensor data. Went on a 5 mile drive. ABS sensors were showing speed. Watched cluster closely. No error messages or warning lights on cluster. Speedo working. Everything fine. Pulled into gas station and shut car off.

Restart car, still in Park... CATS SYSTEM FAULT message displayed. BRAKE, ABS, TCS lights on.

Drove away. Speedo inop. Pulled into parking lot to go through scanner. Was able to bring up DTCs under ABS category: both front wheel sensors, and left rear sensor errors... no input. Didn't write down DTC #s.

Monitored other things after driving away. Scanner was receiving vehicle speedometer input, although speedo inop.

Stopped again to go through the scanner. This is when things became weird. I could no longer get ABS category to come up. Scanner displayed "Error communicating with ECU". Same thing when trying to access Adaptive Dampening. Turned car off and on a couple times. Still couldn't access these categories like before.

Drove around monitoring other things. Scanner was not receiving odometer input.

So, the scanner can read the vehicle speed. Should I assume the VSS is OK?

The wheel sensor errors on 3 wheels... could they have all gone bad at same time, or could it be ABS module that's gone awry, especially since I'm having issues accessing that category on the scanner now?

What data on the scanner should I be looking at that may help pinpoint where the issue might be?

 

It may be either power/ground is not reliable (wiring/fuse/relay/etc) to one or more modules or an SCP issue.

You can get lots of info from the workshop manual (& Electrical Guide).

Once your scanner can no longer see the modules I think you need a meter & the above resources. You may be able to figure a single point failure which would explain what you see.

 

I have a workshop manual stored on my Android, but the PDF reader app keeps hanging up when trying to open the manual... 5,000+ pages... I'm going to download additional apps to see if they work.

Today... no fault messages, but ABS light on. Scanned. Was able to access the ABS and Adaptive Dampening categories that I couldn't access before.

ABS DTCs:
C1155 Wheel Speed Sensor Front Left Input Circuit Failure
C1233 Front Left Wheel Speed Signal Missing
C1145 Wheel Speed Sensor Front Right Input Circuit Failure

POWERTRAIN DTC:
P0500 Vehicle Speed Sensor A./Vehicle Speed Sensor Circuit Malfunction

ADAPTIVE DAMPENING DTC:
U1041 Vehicle Speed Signal Invalid or Missing Data

There's one DTC under Instrument category, but it predates the current issues by a couple months...
U1262 SCP (J1850) Communications Bus Fault

I monitored the ABS wheel sensor speed through the scanner, and I'm getting a speed reading on all four, despite the ABS DTCs and ABS light. How can there be readings of the wheel speed sensors if there supposedly is input circuit failure?

I notice that my DTCs keep changing. Today, there was no error on the left rear wheel like before.

 

Update:

Was having just a steady ABS Light for several days.

I started checking things. Looked at and touched some fuses. Checked for bad front hub bearings, and that the front wheels were spinning good. Only touched a connector at the ABS. Just looked at the front wheel sensor harnesses.

Start it up and the ABS Light was finally out. Thought maybe it was something I'd just touched. Drove it... no ABS Light on.

Park it. Go to read codes. Still had the DTCs showing up, but while I'm sitting there with the scanner, and the key on but car not running, I see the DSC light on the cluster blinking.

Now, why was this happening when the car was not moving?

Owner's manual says if it blinks, it's doing it's thing. If it's steady it's a fault.

OK, I see in the AJES Guide, a blinking light means the DSC Module needs configured. Now, why would this happen?

 

This all sounds like a faulty wheel speed sensor or the wires to it to me.
You need to have a good look at the induction ring. This could well show signs that it has been touching the sensor.
This is often caused by corrosion between the ring and the cuausing the ring to swell.
When faulty these can give reedings that are way outside the correct range and can result in comparative errors creating faults on the sensor on the other side as well.
It can also result in the modules thinking they are out of range and need re-calabrating.

In short I would still change the LH front speed sensor as they are a known common fault as the cars get older.
I have had to change two of my ones over the years, both the rear ones.

 

Found TB which mentions DTCs I've been having. It came out 13 months before my car was built though, but it's for MY2000 & up. Mentions water can get into front WS Sensors. Idk if this could be the case. I've had this car 8-½ years. Never had issue like this before. Only drive 500 to 700 miles a year. I don't drive it in rain, snow, or salt. Car is like new underneath. Still under 100k miles.

I'll have to check WSS & see what condition they're in. Just can't see them having water in there, or grime. I did read about solder getting old & cracking inside ABS module causing wires to come undone. The car is going on 21 years old. I guess that's possible. With that in mind...

Today, I started it. DSC Light was flashing. Went and jiggled wires near ABS and pounded on ABS. Went to check the light, and it had quit flashing and was on steady with CATS & DSC FAULT messages. I did this a few times. Each time I started, the light was flashing until I went & pounded on the ABS. The last time, I restarted and just sat in the car a good while to see if the light went to steady by itself, but it didn't. So, pounding on the ABS seems to cause light to go from flashing to steady. Maybe problem is there. The other day, touching wires by ABS made ABS Light go out. I need to do pinpoint tests from FSM.

I plugged scanner in. Same DTCs I'd been getting. Was able to get into Adaptive Dampening. Read a couple things I'm still trying to figure out...

Damper Firm - Error - Yes
Damper Firm - Low Vehicle Velocity - Yes

And, there's this one...

DSC Sensor Supply Voltage: 123.03 Volts

123 Volts?!

Haven't done any work on car recently. A/C under dash stuff in '17. Rear window regulator in '19. Did brakes & rear stab links few years ago.

Earlier this year, replaced battery. The one I put in in '14 kept going dead repeatedly. Stopped that with new battery, but now I have electrical gremlins.

Most recent issue immediately preceeding this ABS/DSC thing was I blew the cig lighter fuse.

Add on: One thing that happened couple weeks ago that never happened before was I found the sunroof popped up and all four windows a quarter of the way open, but yet the car was locked. Like the global opening partially worked by itself. I didn't press the fob button to make it do that. I wasn't even home when it happened. That happened after the cig lighter fuse incident, and right before the DSC/ABS problems. Electrical glitches all of a sudden.

If there was any time I expected electrical issues, it was when the car was 20ft away from a lightning strike, but that was 7 years ago. There were no issues then, except the starter ran on when I started it to move it away from the tree that got hit.

 

OK to reuse ABS Sensor clips if troubleshooting? Do new sensors usually come with new clips?