On a 2004 XJR, I started the car and the tach stayed at 0, It went up when I reved the engine and then back down to 0. I turned the car off for a minute and then started it again and the tach worked fine, idled around 500. Both times there was an error message that Cruise was unavailable.

Any idea what could cause this and how to fix it?

 

Check battery is first thing to do on these cars when faults occur on start up

 

Three things come to mind

1. Battery
Do a load test (engine off) and make sure it does not drop below 12.2v

2. Earth Fault
Check the earths behind the headlamps

3. Pin fault as per TSB
Pay attention to the pins at the IC and ABS, replace if needed

See these links
http://www.jagrepair.com/images/TSB/...%20Cluster.pdf

http://www.jagrepair.com/images/TSB/...%20Cluster.pdf

Cheers
34by151

 

Faults at initial start-up which clear when the engine is stopped and restarted after a minute or two are a good indication that the battery is well past its best. The voltage at the second start is higher than the first because it's had a good belt of charging current from the alternator after the initial start.

 

Thanks guys. I had seen mention of sensitivity to battery output, but then I forgot when it actually came to it.
Assuming the battery needs replacing, is there a recommended brand?

 

Varta H3, which costs between £80 to £90, fits the holder and is 100Ah and (I think) 830 CCA.

That's what I fitted; got it from Battery Megastore of Tewkesbury. (No connection, just satisfied customer).

 

Varta are fantastic batteries but twice the price in OZ..........................grrrrrrrr!

 

I put in an Energizer the last time. I always go for gel cell AGMs. I'm not a fan of liquid batteries in trunks and interior locations.

 

Tachometer signal is carried to the cluster via the CAN network. I would suggest first looking at any flight data that has been recorded and any CAN associated faults to any system.

 

I guess Bosch are as well ? 'Fraid I'm not up on what are and are not reputable Japanese or Chinese makes, which are probably more commmon in your part of the world.

 

I don't know if they are still doing so, but Varta made many if not all of the Bosch automotive batteries, at least for a period of time. Pep Boys carries Bosch but you may have to have them order an H8 for you.

In the U.S. there are only three or four battery manufacturers left, Johnson Controls, Exide and East Penn. Between them they make virtually all of the major battery brands sold in the U.S., including Interstate, Sears Diehard, Autozone, Walmart, NAPA, O'Reilly, Advance, Costco, Optima, etc. Johnson Controls now owns Varta, by the way.

Check the specifications for the AutoZone Duralast Gold and Walmart EverStart MAXX H8 batteries and compare them to the Bosch. You'll find the specs to be quite similar. If the Bosch still comes in a white translucent case it is probably still made by Varta and is probably an excellent battery. The OEM Varta in our '04 XJR lasted eight years.

Walmart has an excellent warranty and I've been buying some of our batteries there for years because if the battery performance declines within the warranty period you may only have to pay $20 or $30 at most for a new one.

When I replaced the battery in our XJR I really thought I wanted an AGM, but I couldn't find one in the H8 package that offered CCA equal to the available (and less expensive) standard vented lead acid batteries. I bought the AutoZone Duralast Gold simply because it was the only H8 in stock in my area, and I've had zero problems with it in over 2 years.

My two cents!

Cheers,

Don

 

Don, the specified battery from original literature denotes a silver-calcium chemistry. Sadly, finding one is proving rather complex. The Bosch S5 series is silver-calcium.

https://www.pepboys.com/product/deta...04.2L%2520DOHC

Bosch 36/96 Month Battery - 900CCA/1080CA - RESERVE MIN = 185 - REPLACEMENT BATT CCA: 900 - S5 PREMIUM

 

David,

Thanks for the reminder. The long life of the OE battery in our XJR is certainly a testament to the success of the silver-calcium technology!

I just looked up Varta's website - they now have a site specifically for the U.S., but when you search for a dealer, the U.S. is not one of the countries you can select from:

http://us.varta.com/

Their top-of-the-line battery is called the Silver Dynamic, but I couldn't find any statement that it uses lead-calcium-silver grids.

Cheers,

Don

 

I contacted Varta directly via phone. They do not sell or distribute any automotive batteries in the North America market. I also contacted both Interstate and Johnson Controls, and their silver-calcium lines have been discontinued a number of years ago, and they do not have an offering at this time. Interstate is recommending the group 49 series, which they said was a fit for Jaguar, and I asked, "is this a silver-calcium," and they responded, "no it is lead-antimony alloy," which is not a good fit for the charging system's set float voltages. (14.6v~14.8v) Both lead-antimony alloy, and AGM's are not the best fit, and charging float voltages should really never exceed 14.2v for those technologies. The lead-antimony alloy will gas off, and the AGM will overheat, leading to cell separation. Bosch's S6 AGM states on the battery itself "Recommended Charging Voltage 14.4V +/- 0.2V"

Parts stores like O'Reilly's (SuperStart-East Penn) has no silver-calcium. AutoZone's (AutoCraft-both Exide and JC) if Exide, it is antimony-calcium, and older JC can be silver-calcium, but it's been years since JC produced it. Pep-Boys' Bosch S5 is one of the only silver-calcium batteries left in the North American market that I'm aware of.

 

I did hear from Exide today, and their antimony-tin-calcium Exide NASCAR Extreme L5/49X will take charge voltages up to 15v, and is designed for the BMW/Jaguar application. Home Depot carries them, now @ $109.00 40 month free replacement & jump start. 108 month pro-rate. 1080ca 900cca 185m/25a reserve capacity.

 

I'll keep that in mind for the next time around. Surprised the price isn't higher actually.

 

With the car off the battery reads 12.54V, going up to 13.5ish with headlights and heater fan on. So that doesn't seem to be the problem.
It was suggested by my trusted mechanic to leave the battery unhooked for a while. I left it unhooked for 3 hours and when I started it up afterwards the tach went from 0 to ~7200. The engine idles where it should, but the tach now treats just over 7k as 0. Maybe I didn't leave it unhooked long enough? Or something else?

 

Check out the items i posted in post #3 specifically the items in the TSB
Id be looking at the connection at the I/C


Cheers
34by151

 

Gareth

Do you still get 'cruise unavailable message'?

The tacho and other clocks are driven by mechanical gears

which are elecrically driven, I presume like the el cheapo clocks

and they are all plastic!

Hence it is possible to have a physical glitch in the gears.

A fault like that is very rare in this Jag and I would not like to have

to try and repair it! Just thinking aloud.

 

Yup, cruise still unavailable.

It seems that after unhooking the battery, that the tach works now, it just parks in the wrong place.