Hi all,
VEHICLE: 2004 XJR
SCENARIO: Changed RH indicator bulb. I had to remove the headlight rear cover as my fat hand wouldn't fit. To remove cover disconnected 2 grounds attached to radiator support (G2, G3 per ground locations on schematic). Moved grounds and large bundle of wires down a bit as cover would pinch them. Put all back together, reattached grounds, splash guard back on. Indicator flashed - did not start vehicle though. Then proceeded to replace all 8 coil packs as #3 was bad. Probably moved a few different wire bundles around a little in process.
PROBLEM: Code P1637 along with message screen faults; low brake fluid, DSC not avail, cruise not available, CATS system fault, air suspension fault (this was there before working on it), parkbrake fault and ABS fault. Cleared P code with OBDII but it came back, as expected. Did the reset by removing negative battery cable and touching to positive. No change. Drove it and coil packs fixed that problem but of course shocks were on FIRM and variable power steering assist was low.

What did I do and how do I fix? Already double checked reattached grounds.

Thanks in advance, I'm sure somebody has an idea of what I did!

Bil

 

IMHO it is probably a ground that is not good enough anymore after your operations.
Bad ground may cause multiple "unrelated" faults.
Check again your main grounds

 

+1 on rechecking your grounds AND any connectors in the wiring that you moved around.

Also, several months ago I had to replace a bad left rear ABS sensor on my wife's 2004 XJ8. I had an independent shop do the work and the tech was able to clear all but one code. The last one simply wouldn't clear and he felt that it was possible that it would require a reflash of the ECM which was something his Bosch equipment could not do. He drove it some number of miles to make sure the codes were cleared and stayed clear and a number of ignition cycles but that one code would not clear. Since it had nothing to do with the ABS or ASC the reason for the code was a mystery.

I told him I'd keep an eye on it but when I left the shop on the drive home I hadn't gone 1/2 mile when that code also cleared and has never returned.

The moral of this story is that some codes require X number of drive cycles and/or ignition sequences in order to clear and the svc. manual is loaded with them but we seem to ignore them when we're in the midst of trying to fix things. Just another one of the joys of owning a Jaguar I guess

 

Double triple checked grounds and found one connector that hid itself from me quite nicely. It gets the hide and seek prize today. Hooked it up. All is good now.

Thanks for quick responses.

bil