Hi,
I've read a lot of posts on this forum regarding this issue, so have some knowledge, but I'm stumped. Started with intermittent ABS light coming on but going off shortly after starting to drive. Now ABS light is on continuously once the car is started even without movement.

• Tested battery and it shows 12.8V and was replaced in May of 2016.
• Previous owner had front passenger side sensor replaced (at over $500 with half of that labor!).
• Previous owner had ABS module replaced (at over $3000) in October 2017...less than one year ago. Is this still under warranty? Is warranty transferable to new owner?
• Cleaned both front ABS sensors with no improvement

Had to believe a new module has gone bad in less than one year? Any other ideas? Is the ABS idiot light self clearing or would I need a scanner to clear the code? Any recommendations on an ODB2 scanner?

Thanks for your help!

 

What is the condition of your wheel speed sensor harnesses? The rubber boot at the end of the harness which connects to the wheel speed sensor tends to deteriorate over time and permit water and debris to enter the wiring. I cleaned up the cracking and splitting rubber boots on my wife's 2006 XK8 with a damp cotton rag, dried them thoroughly with a hair dryer, then covered them in neutral-cure RTV silicone sealant more than five years ago. Doing that (and scrubbing all four wheel speed sensors with dish soap and an old toothbrush at every oil & filter change / tire rotation) has kept the ABS/DSC dash warnings from coming back on her car....

Regarding an OBDII scanner, I have an iCarsoft i930 which I purchased on amazon for about $125 in early 2016. It works fairly well most of the time but has refused to communicate with some of the modules from time to time. Keep in mind that iCarsoft has no customer tech support at all so if you decide to order one, make sure you can return it for a full refund if it refuses to work for you....

 

Bob Gauff (motorcarman) is a professional Jag mechanic and member of the forum located in Decatur. You could contact him via a PM and arrange to have him run diagnostics on the car. A skilled indie within driving distance is something many of the forum members don't have.

 

Without the DTC we are all guessing.
My GUESS would be a front wheel speed sensor link harness.

Anybody else have a guess??

bob

 

Hi Bob,

I did test both front sensors with an ohm meter and I got something like 1180 ohms which I think is acceptable. Now looking to test all 4 wires from the ABS control module. I removed the 37 pin plug but don't know what I'm testing. Is it the wiring harness that goes to each of the wheels? If so, I have a drawing from another post but I'm getting no reading from any of the suppose wheel sensor pins, so I assume I'm either looking at the wrong pins or I'm suppose to measure continuity from the ABS control module and not the harness. Is there a better way to test the wiring and harnesses?

 

This pdf should show the harness connections for your car. The resistance readings of the sensors looks okay. But as I mentioned before, testing for the DTC is the best way to find the fault.

ABS Sheet XK8.pdf (application/pdf Object)

 

I have no idea about ohm measurements to/from wheel speed sensors 'in-situ'. I would disconnect the link harness from the speed sensors at each wheel to see OPEN CIRCUIT from the ABS module main connector individual pins. Then 'SHORT' the connector with a piece of wire to see zero ohms at each sensor while moving the harness to see if there is an INTERMITTENT open circuit to simulate suspension movement.

This only works if the fault is detected while you are watching!!!!!!!!!!! If the fault is intermittent and the module detects it, then it will flag a DTC. The module is ALWAYS watching so I would interrogate the module. I know it takes 'special diagnostic equipment' to read DTCs from specific modules but people go to doctors and have tests with 'special-diagnostic-equipment' all the time and never complain that they cannot afford to have that MRI or X-Ray machine at home!!!!!!!!!!!!!!

They seem to be the first to complain that their $80,000 car needs a $200 diagnostic machine that can do 80% of what the $20,000 dealer machine can do.

I have three WDS and two IDS Jaguar diagnostic units so I use DATALOGGER and can also look at the DTCs in the relevant modules. DATALOGGER can monitor sensors through the module while the vehicle is in motion and record events.

There are common faults and some 'workarounds' for these cars but sometimes you just have to 'go to the doctor' and have a 'procedure' done. (or study and buy the expensive machines yourself)

Some doctors don't have the equipment and can cure anything, some doctors have ALL the equipment and have NO IDEA!!

just sayin'

bob

 

One easy check to do is to disconnect the main connectors to the ABS unit at the ABS unit. There is a large pull tab connector and a smaller power connector below it on my 2000 XK8. Clean both with a good electrical cleaner and hope it works. Good luck

 

 

 

I really think it's time to pay motorcaman a visit. He will be able to identify all of your problems, and if the module is faulty you will have documentation to present to the dealer.

 

Drove the car again and the check engine light is now out! Changed the brake fluid which looked pretty dark and bled brakes. Cleaned both rear ABS sensors which were both pretty dirty. No impact on ABS light, however.

 

as unrelated as it may seem, check out your wheel bearings, the left rear is first to go typically. If the bearing is bad the abs signal can get interrupted and this leads to a multitude of errors and error messages. I personally has, engine failure, transmission fault, no abs, track, dsc and several other. I replaced the bearing and everything was perfect for over 10K miles.
wj

 

 

No!
If I didn't clear my error messages... even after a restart, at times I would still have a message. I even received a message about my door(S) being ajar.
If you can do it your self it is pretty straight forward and quick, if you must enlist someone else I would image an indy shop would do it without charge in anticipation of getting the repair.
wj

 

 

This morning, the check engine and ABS lights were on when I turned on the ignition. Had the following codes read from the OBD2 connector:

P1637 - CAN link engine control/ABS control module network malfuction

C1155 - Wheel speed front left input - circuit failure

P1799 - CAN transmission control module/ABS control module circuit malfunction.

I recall reading other threads regarding having Jaguar pulling codes indicating front left wheel speed sensor only to find it was really the ABS module. To recap, I have checked the resistance of all 4 wires/sensors from the ABS connector and they are all showing 1K ohm approximately. At this point, do I assume this is indicating an ABS module failure? I'm under warranty for another week!

Thanks!

 

It could be the cable to the left front has a break that only shows when the cable flexes, but since the warranty is about to run out it would probably be best to take it to the dealer.

 

why fight the clock? take it to the dealer and have them check the replacement before the warranty expires. (don't assume a newer replacement is good)
the bearings can be checked while the vehicle is on a lift, grab each tire at 12 and 6 o'clock and try to rock it in and out...if they all seem similar with regard to the amount of motion-assume they are okay. If one or two show significant motion that might be your problem.

 

Not trying to fight the clock. Just trying to learn everything I can before going in there. I have an appointment with the dealer tomorrow but I have a very high distrust of most dealers. I was hoping for a relatively definitive diagnosis before heading in there.