After 18 years, I think I will now need to sell my beautiful 2000 XJ8 for scrap! Body looks showroom new!
88,500 miles.
A new rebuilt transmission will cost 6-7K, I think…more than the KBB or NADA estimate of the car’s value!

After this yellow (Amber) warning appeared, the car seems to be in limp home mode.
I checked with my OBD-II code reader & no codes stored. (Maybe transmission faults are not read my my OBD-II since not a check engine code?)

My battery is new 11-2017:
Bosch Advanced AGM; 90 AH, 850 CCA.

I tested Voltage @ the battery with a multimeter just in case it was a bad battery causing this transmission fault message.
12.45 V, so ~ 80%, surprising since I just drove the car day b4 for ~ ˝ hour each way.
I charged it overnight with my CTEK MUS 4.3 using the normal (14.4V setting) The battery has a sticker that says to charge @ this voltage. (I know some other AGM batteries need to be charged @ 14.7V, cold weather program)
Now Battery @ 13.22 V, excellent charge!

Sadly, still have transmission fault. I have not driven it, just turned engine on to see if fault would go away after charging battery fully.

Any suggestions? Any way to know if it is, in fact, a bad transmission? I’ll probably have to pay Jag dealer or an Indy mechanic to test it & tell me that it needs a new transmission. Could it be low Transmission fluid? I know it is sealed & supposedly lifetime but, maybe there is a leak? I read some other posts where it was a bad gear position rotary switch, $500 part. Another post had a P0778 fault code…I have no code per my code reader.)

Thanks!

 

You need to visit a Indy to read transmission codes. But first, do a hard reset. Remove neg. cable from battery, touch to positive post for about 15 sec. Jags are expensive cars if you can't do most of the repairs and maintenance.

 

I may need to be driven as well after the hard reset. Worth a try if it clears the warning light.

 

You can read with a meter at the Transmission ECU through the transmission sensors and solenoids for a cheap DIY look to see it if you have one fail . Based on your readings you can replace the effected item yourself by dropping the oil pan where all the electrical things are . The main transmission connector has a history of getting contaminated by fluids from above . I beleive it is a bayonet connector that comes off like a air hose coupler . Once you have the oil pan off it would be a good time to do the pressure regulator / Transgo mod .

There is someone I assisted in Tennessee on doing this but I can't remember who to link you to the written text but here is a pic for the 2001 ZF5HP24 transmission .

 

Sometimes you just have to call the tow truck and take them in -- You can get a ZF rebuilt for much less should it require fixing/ rebuilding.

Unless you see fluid it's unlikely to be low -- could be a number of things causing it.

With 88k and your obvious low miles per year going forward -- if it can be fixed w/o a full rebuild that would be my direction should it be a drum or piston problem.

It's not unusual for a car near the bottom of the value curve to have a major issue that costs a big chuck of the value .... but, what else could you buy for that amount ?

 

If needed shop around for your rebuild, I had mine done in November for $2,100.

Good Luck

 

Depending on the engine size & milege if small v8 then 5 speed zf gearbox & around 100000 miles, best to drop the pan off the gearbox & look for metal in the oil metal if metal present then gearbox out, rebuild, 2nd hand box with low miles or rebuild. No metal possible solenoid replacement. Use the correct oil for refill / topup, most important.

 

Hi Steve,

There are plenty of things that can trigger Limp Home Mode besides internal transmission problems.

For example, as far as battery voltage goes, what matters isn't the battery's static charge, but the voltage actually seen by the ECM while cranking and the voltage seen by the ECM, TCM and other modules while the engine is running. Corrosion on battery power connections or ground connections can reduce the supply voltage at the modules, causing hard-to-diagnose electrical gremlins.

The ECM, TCM, ABS/TCCM, Vehicle Speed Interface Module, Gear Selector Illumination Module and Instrument Cluster communicate via the CAN bus, a network of Yellow and Green wires. Corrosion on or looseness of one or more connectors in this circuit can cause problems.

I'm not certain whether Network (U-prefix) diagnostic trouble codes (DTCs) were implemented in 2000, but if so, it is possible that one or more of these codes may be flagged in your car, and a Jaguar dealer or independent mechanic with the proper equipment may be able to read them, which could help narrow down your diagnosis. Here's the manual for the standard Transmission DTCs:

Jaguar ZF 5HP24 Transmission DTC Summaries

Problems with the Throttle Position Sensor (TPS) can cause Limp Home Mode, since the TCM and ECM rely on accurate throttle position information to orchestrate smooth gearshifts.

I am attaching the AJV8 Engine and ZF 5HP24 Introduction manual that explains the basic operation of the ECM and TCM and may be helpful.

Cheers,

Don

 

Thanks to all who replied!
I have Innova Model # 3130. OBD-II.

I think it cannot read Transmission codes. Only Engine codes.
So, b4 I try to do a hard reset with battery to clear code, I better find out for certain that there is some issue with my transmission.
Lady Penelope, I appreciate your information however, I do not know how to “read with a meter at the Transmission ECU through the transmission sensors and solenoids for a cheap DIY look to see it if you have one fail .”

I am not a mechanic. I think you’re saying I need some special scan tool & must connect it to The Transmission ECU in order to read transmission codes. I will have to let an Indy shop do that.

B4 I posted, I searched for people with the same Transmission Fault, in case there was some helpful info. I watched a video of a guy dropping his transmission pan to replace a part & refill with fluid & he had much trouble! Bolts stuck, sheared the head off one, even after spraying stuff on it to loosen it. Had to buy replacement bolts from Jaguar. No thanks! He had his car up on 4 jack stands, I only own 2 & can easily see myself getting I over my head & needing several days to fix it & really do not have a good way to leave the car up like that unless I keep my other car out of the garage & leave the garage door open. This is fine for several hours but, not several days. I’ve replaced ignition coils, cleaned wheel speed sensors & removed & cleaned Mass Air Flow Sensor & sprayed throttle body & changed the oil… but that is about it.

yeldogt, I understand your point. If my car is worth 4-5K at best when fixed, It may make more sense economically to pay even 6-7K to fix the transmission vs. selling the car as is for scrap & trying to buy a new car, either Jaguar or even a used Jag or similar car. Or it may not, depending on what else may break in the next couple years after I fix the transmission. I don’t really like the looks of Jaguars after 2004 & I would not want to buy another 1998-2004 XJ8 or XJR & possibly have even worse troubles.

King Charles, If I knew now that it was in need of a rebuilt transmission & could get it done for $2100, it would be very tempting to do so. I don’t know a trustworthy, competent Indy shop to work on my Jag. I had taken it to the only Jaguar dealership in the the city, where it cost more but, I had an SA who I have known for years & always gave me a lower price. He recently left though. So, I will find out the cost to check & diagnose the Transmission fault from both Jaguar & from an Indy shop I know of (but never used) that specializes in Jaguar. I’ll also try to find out the cost of a rebuilt transmission from both b4 I take it in. I think it is ~ $6500 through Jaguar. If the Indy shop tells me ~$2100 I’ll seriously wonder how it can be that much less, would they do it right? I’d be very angry if I threw $2k+ at the Jag & the transmission was still broken or worse.

Kove, I have seen videos of dropped transmission pans & some with metal shavings & some w/o. I understand that the presence of shavings is diagnostic. Also discussion on using the right oil. But, I’m not going to DIY. I realize that leaves me vulnerable to an unscrupulous mechanic who may take the pan off, see no shavings & know the fix is relatively inexpensive but tell me there were shavings, perhaps even add some to show me & tell me that I need a new transmission when I actually do not.

Don, Thanks much for the PDF which I saved. I do not have corrosion anywhere near my battery which I replaced myself a few months ago. I don’t own a battery load tester. Just a multimeter. I also have a tool (Innova Equus Battery Alternator Tester 3721) that I plug into the cigar lighter socket & I can rev the engine to 2500 RPM & see my alternator putting out slightly over 1400 V so it is charging just fine. (I know you can test the alternator from under the hood with a multimeter but you need a helper to rev the engine. This is easier.)

IDK if I have corrosion or loose connectors in ECM,TCM, ABS/TCCM or not. I probably can find all those using your Engine & Transmission Intro document & wiggle them to see if anything seems corroded or loose but, will probably let the mechanic troubleshoot.

If I had the tool & knowledge to read transmission codes I’m sure I could post it here & maybe learn exactly what needs to be replaced. Maybe I’d get “lucky” & it would be something relatively inexpensive that does not require tearing into the transmission.

BTW, I did not get a message saying limp home mode or restricted performance. The Transmission Fault amber light message appeared when I was ~ 5-10 miles from home & on my way home. The car didn’t seem to drive right, seemed sluggish so, when I read that transmission fault can put it into limp mode, I assumed that is what had happened. Amber light (vs. red) supposedly means you can drive it so I do not think I need to have it towed to a mechanic. I can drive it there, carefully.

I have another car so , this is not an emergency. I’ll probably take it somewhere week after next. I’ll make some phone calls re costs this coming week.

 

Going into transmission limp/safe/restricted (whatever the dash displays (can't remember)) mode is typically not common w/o actual transmission related problems. At least that's my experience being around these cars for a long time.

The low battery will cause all manner of problems -- but I have never had a transmission fault pop up. Would be interesting to hear others on this? The low battery will throw codes -- but, they will go away after the volt condition has been corrected.

It sounds like the OP has a true transmission fault -- he needs to take it to someone who can read the codes. IMO ... finding a good independent who works on Jaguars would be preferable. We are now 15 years out from new on these cars ... many dealers don't even have people who remember these cars when new and since they typically work on mostly new ones .... they are not always the best to work on the old ones. When I go to my local dealer I see one of the service writers and one mechanic from 15 years ago.

Some dealers (most) don't even work on transmissions .... they install new ones from the factory and send the others out.

Getting the codes is the start ..... my memory was the rebuild cost on these was around $2500. Not including R&R. The factory place in CT is more .. but they remanufacture if my memory is correct. A few members have taken transmission to them -- I'm sure a search will find. The ZF is a widely used transmission -- it's not an unknown commodity.

 

Hi Steve,

In addition to the cable terminals at the battery, the battery power cables and grounds have many connections throughout the car, including at all five fuse boxes, the alternator and starter, and the "False Bulkhead" connector. There are around two dozen ground points. Corrosion on these connectors develops over time and produces cumulative resistance that can pull down the voltage seen by the ECM and other critical components.

With your tester, one easy test you can do is to check the battery voltage at the cigar-lighter (you're looking for at least 12.5V after sitting overnight, preferably 12.6V or better). Now, start the engine and see how low the voltage sags. Your tester may not respond quickly enough to show true voltage sag, but it may give you an idea of whether the battery and its wiring are able to deliver good voltage while cranking. If the voltage while cranking falls to 11.5V or lower, spurious codes can be triggered.

Keep in mind that many of the sensor circuits rely on reading precise voltage and/or resistance variations, down to hundredths of a volt or ohm. So any resistance added by corrosion or looseness of connectors can lead to incorrect interpretations of sensor signals by the ECM, TCM, etc.

In the manual at the link below you can find the locations of battery power and ground connectors, as well as all other electrical connectors for every circuit:

Jaguar X308 Electrical Guide 2000

Cheers,

Don

 

There are two different models of the ZF box hence the question about motor size, one is 5 speed other a 6 speed. the 5 speed has know weaknesses which tend to show at around 100000 - 125000 miles. if you have concerns about dodgy mechanics then be there when the pan is dropped. Without all the info we are all dodgy mechanics - guessing whats wrong.

 

I think a 2000 XJ8 would not be the 6-speed (ZF 6HP26).

 

The ZF 6HP26 was not introduced until the 2003 S-Types and 2003.5 X350 XJs, so there should be no confusion on that point. As far as I know, all the normally-aspirated X308s with either 3.2L or 4.0L engines got the ZF 5HP24 5-speed transmission. The supercharged cars got the Mercedes-Benz 5G-Tronic W5A580.

Cheers,

Don

 

I was busy last week with unrelated things.
My service advisor @ Jaguar dealer is no longer a service advisor! I’ve been going to him for years & he usually gave me a discount.
So, I did not get a price from Jaguar as to cost to diagnose problem & if required, rebuilt transmission, cost.

I have not been driving the Jag but on Saturday,5-19, I took it out for a test drive. As expected, as soon as I turned engine on, the Transmission Fault with amber light was there. As b4, the car was very sluggish as if it had no 1st gear. I did not see any message saying restricted performance (I have seem that message b4, with other issues, such as bad ignition coil) but, it sure felt like it was in limp home mode! I drove for ~ 15 minutes, in very light traffic. I kept an eye on the tachometer. I wanted to see if I could spot the fact that 1st gear was “gone.” As if I am starting in 2nd gear. I even got up to 45-50 MPH & switched to manual & worked my way down to 2nd & then back up to 4th gear & then moved he J-shifter back to Drive. I never saw the expected movements of the tachometer! rather than moving up to 2500-3500 RPM & then dropping down, as the car shifted to the next higher gear, the tachometer just moved slowly & steadily up or down depending on speed. I’ve never seen that behavior b4.

I got home & tested the battery again. 12.91 Volts.

Today I called an Indy shop specializing in British cars. I had a long talk with the owner who is a mechanic & seemed very knowledgable.
He asked several questions; Did the car lurch FW with a big shudder? No. He said sometimes there is a hairline crack that develops in the front drum ~ my mileage that is due to a spring with too much tension. He described how the transmission fluid behaves in this case, that would explain the missing 1st gear (I forgot the details). He said the dealer charges $8500 for new transmission & he has done many with a “more robust” drum for $3200. (He mentioned the name & I forgot it.) However, he said based on my answers he is doubting that it is a mechanical issue. Rather he suspects some electrical issue which would cost less. He said he has XJ8s with 150-200k miles on them & I don’t have that much mileage on mine & it is 18 years old & I should drive it more.

He wants to see the car when cold so, had me drive it to his shop & leave it so they could check it 1st thing tomorrow. I drove it over this evening. To my complete surprise, when I started the engine (Unlike the 3-4x since this issue began) there was NO “Transmission Fault” message, NO amber light. The car behaved completely normally!
Drove normally, Not sluggish. Changed gears normally. I could see the RPM go to ~ 3500 & drop a bit as gears changed. It “Fixed” itself.
WTF?!

I now suspect he was right about it not being a mechanical issue.
I’ll see what he says tomorrow. He obviously has the equipment to read Jaguar Transmission codes. I just hope I don’t hear the dreaded: “Can’t find anything wrong, no codes, working normally.”

BTW, I had recently placed a sheet of cardboard, under the front to see if I could pick up any evidence of leaks. There was a drop (1 Ľ”size) passenger side, front end. Since that is not near where transmission is, probably unrelated. Now I think it is another oil leak which will need valve cover gaskets replacement. I had that done 3x a few years ago! 44,606 miles (@ a Bad Indy shop), both sides done. Again @ 52, 385 miles @ dealer to fix leak & also had secondary tensioners done (just to prevent future failing of these crappy plastic parts). Leaked again just 4 months later @ 54, 674 miles (Dealer did 1 side again, Under warranty)

So, I’m cautiously optimistic.
KBB says worth $4,104 if sell to private party, 1,938 value as dealer trade in. That is in EXCELLENT condition.


NADA says $3,950 clean retail, $2275 clean trade-in.

My paint job is immaculate. Interior excellent. Leather & wood trim are flawless. Not worn or scratched or sun faded.

Maybe KBB & NADA are not the places to correctly value Jaguars.
If I get the Transmission issue fixed, is my car really only worth a few thousand?

 

Which proves the alt is working but not whether the battery is OK.

I'd say it's suspect i.e. we don't know.

If you avoid charging it overnight (or for a day) what volts is it before you start the car but have a heavy load (at least headlights for 2-3 mins) on?

Not saying it's the battery but has to be worth making very sure.

 

Sadly, it depends on the market but in some places, that's exactly correct. It will also depend on the potential buyers. For example, if you found someone that appreciates the cleanliness of the car and low mileage and they think they can get it going even if it takes a trans swap, they might pay the upper range. But you'd have to do a lot of research with cars that are listed (and ideally what they actually sold for) in your area to determine if they are going at, above, or below book value. A lot would also depend on your hurry to sell. If you can afford to sit on it while waiting for the person that would appreciate it more, you'll get more in the end. If you need to unload it quick, that's going to drive your price down.

 

In reading the electrical items in the transmission control valve body you would look for resistance on a simple volt ohm meter

the 2 speed sensors should read about the same resistance

Temp sensor should read X resistance

The 3 shift solenoids should read the same resistance compared to each other .

the 5 pressure regulators should read the same resistance compared to each other .

This if it shows a item out of comparison to the others you would change out that item by dropping the oil pan .

This is a cheep and simple way to seeing something without a code reader per say .

PM me for assistance on meter usage

 

I called the shop since I have not heard anything all day. Spoke to a receptionist. Shop Forman test driving my car now. They found 2 codes; brake switch & transmission control module. They cleared the codes & are testing to see which one comes back.

I had the dealer replace the brake switch in 2012 @ ~65,000 miles. Is it typical that the same part would fail again in ~ 6 yrs./24,000 miles? I had paid $167 for the brake switch replacement. (I know about threads on this forum to replace it yourself but required a helper & was difficult due to cramming yourself in the drivers footwell & reaching far upwards)

Has anyone had problems with the TCM? Is it an expensive part? I see $40-$85 on eBay (used) Don’t see Google results for new. Also read about it getting wet & needing to be dried out. (Mine did not get wet)
Maybe it needs to be reprogrammed?

 

There is a updated brake switch part #

There is a TCM for the X308 in the salvage yard I visit , guessing he would charge $ 50 for it

Would need all the numbers you can see on your module

Before you were to change the module verify the connector on the transmission case itself is cleaned as this gives issues on this model . The connector I believe is a push / pull connector like a air hose so don't try twisting it too hard .