2004 X-Type Electrical issues. Don't know if early or late 2004 VIN SAJEA51C04WD83731
Hoping someone familiar with dipped beam/headlight circuits is still around on the forum.
Road trip in CA over Christmas in 2 heavy rainstorms. On Freeway Trans suddenly downshifted out of OD into 3rd-N-3rd-N,etc., and gear selector indicator lamp turning on/off- "Cruise not available"&"Transmission Fault" on Message Center. Fortunately had a OBDII code reader with me that showed p1643 (Trans.Ctrl.Unit fault from battery voltage below 8.5V) Everything else seemed like Battery was OK, so I cleared the codes. Car seemed to return to normal. At 1st stop for gas I noticed L.Dipped Beam out, and Hi beams come on with stalk switch, but do not latch on-they turn off when stalk is released. They do latch on with the remote fob button. Bought/installed new dipped beam bulb-no change-still out. F29 was blown and blows again immediately now, and instrument lights are on in MANUAL, but go out w/ headlight switch in AUTO. Same symptom happened again a week later in rainstorm in LA. This time got OBDII codes p1643, P1793, p1796, p1797 (all still battery voltage/Igintion supply/CAN bus errors, not Trans). same shifting problems. Cleared codes again, car seemed normal again. I looked on this forum when I got home and saw posts from 2009-2009 about dipped beams and also fog lamps. Got the car washed and remembered to try the fog lamps I had not tried before. Immediately when pulled the switch to turn the fog lamps on, they came on, but the instrument lights (not LCD backlighting) went out and tail lights went out. Also no headlight annunciator lamp in dash now, just Front&Rear fog light annunciators work. Transmission problems have not re-occurred. I watched YouTube on waterproofing X-Type TCU. Maybe that coincidentally caused TCU/electrical problems.
Could the headlight/tail light issues be as easy as a bad headlight switch ***'y? or relay?

 

Heck of a post. If I had electrical problems the first thing I'd do is get my battery thoroughly tested.

 

Dan, like swingwing said, I would do a check of your battery posts. Start the car and turn on your seat heaters, dash fan on fast, and the headlights. Let the car idle for say 5 minutes in this state and then put your hand near the battery terminals (near, not on). If you can feel heat coming up, you have a bad cable and it needs replaced. If they seem to be at the relative ambient temp of the engine bay, then most likely all is good.

Based on the fact that your one error code said that battery voltage dropped to less than 8.5V, that is an indication that you have either a bad alternator, bad battery, or bad battery cables (with the cables being the most likely suspect and the battery a close second).

 

Thank you both, Swingwing and Thermo. The OBDII DTC's have not come back. Both instances of that were after several hours on fwy in hard rain. Battery is about 6 mo's old and cables are good-posts do not get warm. My real concern is that the exterior lights seem to be cascading in failure. 1st symptom was simultaneous:
• LF dipped beam (blows F29 immediately when powered on)
•main beams not staying on without holding the turn signal stalk in "high" position
• instrument lights not working
2nd symptom, also simultaneous, happened when I turned on Fog Lights:
both tail lights quit
instrument lights quit in all switch positions
"Lights on" annunciator (>>o<<) quit in all switch positions
F & R Fog Lights and Fog Light annunciators all still work
It seems that maybe the headlight switch ***'y is breaking/shorting inside? and perhaps the L.dipped beam relay is bad-blowing the fuse?

 

Does anyone know where I can find a wiring diagram/schematic of the 2004 x-type headlight/taillight circuits? The only $90 Jaguar electrical manual I found on the web is out of stock. Thanks again.

 

Dan, that battery voltage warning of 8.5v nags at me. Even though your battery is fairly new I recommend you stop by an Interstate Battery store and have them do a load test. I'm not strong on solving electrical problems but have learned that battery integrity is fundamental. I've experienced total battery failure several times over the years, most recently in my '04 X-Type. Here's a diagram from my Haynes manual. If there's others you need PM me. By the way I got the Haynes manual from Amazon for $20 or so. Not available readily in the US so had to wait for it to come from England. This book's layout is not the easiest to use but it's been worth to have as a reference.

 

Dan, PM me your e-mail address and I will send you a complete set of diagrams for your car.

The only other possibility is that the wire feeding the field of the alternator is making intermittent contact and that is causing the alternator to jump in and out. When the alternator drops out, you start running on the battery and that can easily pull the voltage down to under 8.5V, especially under heavy load.

Just to make sure that we are talking the same thing, when you say "main beam", are you referring to the HID bulbs on the outside lenses of the headlights or the lights next to the grille? Pulling back on the turn signal stalk should not affect your low/dip beams (aka, outside headlights). That switch only affects the high/main beams. If you cannot push the turn signal stalk forward and have the high/main beams lock in, then you have a bad turn signal stalk, which could potentially have an affect on your taillights.

 

Thermo -Thanks very much. I didn't see your last reply till just now.
Swingwing - I'm convinced my "low battery" DTC's were a water issue. Never happened B4 or since. I had been cruising between 75 & 90mph in wet conditions on I-5 (CA) for about 3 hours, both times it happened. New battery was load-tested a few weeks ago to isolate possible bad alternator. From what I see in this video, this gentleman makes a good point about waterproofing the TCU. I will be looking at my TCU soon.
- - Just so the info on my fix is here - The clip/retainer for the dipped beam bulb is critical. In the rainstorm, I did not quite get one side of the clip lined up correctly and it was laying on the + contact. Due to larger hands, I now had to remove the battery and battery box to do the job right. This short also fed back on the dipped beam status wire (which is ONLY off F29, not F30) and it took out under-dash F38 which feeds taillight, side marker lights, instrument cluster lighting, dipped beam annunciator in MANUAL ON only, not AUTO. This was also somehow affecting the Main Beam latching circuit.
Correct bulb installation + new F29 & under-dash F38, and everything works.
I found a COMPLETE Sedan and Sports Brake Electrical Guide for 2.0 L, 2.5 L and 3.0 L Gasoline; 2.0 L Diesel
Model Years: Sedan 2004.25, Sports Brake 2004.5
Here: http://www.jagrepair.com/images/Auto...52004.25en.pdf
It opened and saved to my disc, no problem, no added software monkey business.
Hopefully someone else will see this and not make my rookie mistake.
Thanks again, everyone. I'll update after I have time to look @ the TCU and seal it.