It means if the code comes back again after you have cleared it.

As others have said you need to find out what is wrong with your wheel speed sensor before doing anything else.

 

I am ... I am just researching the worst scenario while my car is transported home.

 

Hi guys,

I just want to update what's going on with the car....so I replaced the wheel speed sensor on the left rear wheel (driver side) and took it for a drive and after 30-40 minutes of highway speed driving sure enough...it happened again....the sequence how it happened is:

The "cruise not available" warning and the "ABS" light was on.....then a few seconds later the "transmission fault" was on, then the transmission downshift to third gear and won't upshift (safe mode?) So I drive back home at 50 mph and plug in my "Icarsoft" that I bought from Ebay (it's a good obd reader btw)

The first thing I did was reading the ABS module:

C1236 Rear left speed signal is missing.

Then the transmission module and the same codes from before shows up:
P0701 ---- Transmission control system/ combination of impossible substitute functions.
P0720 ---- Output speed sensor circuit malfunction
P0730 ---- Incorrect gear ratio
P0735 ---- Gear 5 incorrect ratio

At this point, I really feel that it's not tranny related yet...I use live data and can see that my tranny input and output sensors are reading engine rpm...so it's seem to me something in the wheel speed sensor is malfunctioning thats throwing off the tranny and disable a bunch of things..among the things that I lost when the warning lights pop up is:

1. back up sensor
2. the function that when you are in gear and you release the brake and the car moves forward (i don't know what's that call :-) )

Anyway, I know some of the possibility that could messes up the speed sensor is

1. Tone ring
2. Wirings
3. Wheel Hub
4. and finally the ABS module itself.

Anyway, what can I do now to diagnose this issue ...at least starting with the wheel speed signal?

If i reset the codes, the car drives fine until it happens again...tranny shifts very smooth...

ooh also battery reading is 13.4v is that good enough?

 

If possible, I would try and swap the left and right WIRES going to the rear wheel sensors. The wire comes off at the sensor side of course, but also connects further up on the harness, from what I understand (no need to go all the way up to the controller). Then drive again and see if the fault code changes side (a "Rear RIGHT speed signal is missing"). Also , repeat the test by swapping the sensors and see if this tells you something.

 

Aaah...that's a good idea to start....I will go under the car and look for those wirings then.... I made a call to a Jaguar specialist close to me earlier...explaining the situation...they are pretty quick in pointing out the ABS module needs repair...do you know a place to repair the module...just in case it is the module?

 

ASI repairs almost all the moules and has a good reputation.

Automotive Scientific Inc. | Quality Rebuilt Automotive Electronics | Rogersville, TN

 

Thank you I shall give them a call.

 

Before spending any more money, check the wiring to the wheel speed sensors with a multimeter:-

http://jagrepair.com/images/AutoRepairPhotos/ABS%20Sheet%20XK8.pdf

If they are all OK, then look at the ABS module, which you can repair yourself with a soldering iron. There are YouTube videos showing how.

 

Thank you....yeah...this is the order of what I'll be checking on:

1. wiring harness
2. Tone ring
3 and then the module...( which apparently according to some module repair place, the 05 ABS module might not be repairable (one's with 3 screws not the 4)....and I know apparently according to my research ...we can't just install a used ones from the junk yard...it won't work properly....so I'm preparing myself for the worst...for a new abs module from Jaguar.

 

Hi there, I'm a new member and I've had my 1999 Jag xk8 for the last 6 years. I've never changed the transmission fluid...but now I'm encountering a big problem. She's not moving forward in drive...my guess is there's a problem with the transmission, but I'm unable to locate where the transmission fluid should be topped up/changed. HELP!

 

If you do actually need to replace the module, a used one with the same numbers as listed in the CATS in the trunk can be introduced to the ECU by a indy with factory software. But I would do some checking first to see if repair is possible. Don't ask the dealer, they won't know.

 

Welcome to the forum. There is lots of information here on checking the fluid level. Just use the Forum Search. You will get more help by opening a new thread with the title 'Transmission Problem'.

Please visit the new member area and introduce yourself:

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

Thank's for the tips....I am taking my car in to have my indy check over the harness and the tone ring before settling on the ABS module itself.

 

Another data point: https://www.jaguarforums.com/forum/x...-cured-144897/

 

Woow...please please Jaguare Gods...let this be my problem!!!!

 

Update:

hi guys...thank you for all the inputs....after all the dances and nervousness it turned out to be the reluctor ring for...it was split (see picture)..... I dodged the bullet this time....thank's again.

PROBLEM SOLVED

 

Glad to hear it was something "simple". Have you managed to locate a replacement, or are you going to repair it? Thanks for the opportunity to learn something new!

 

The jaguar specialist Indy shop has one used ...so they fix it ($398)...now my car runs like Jaguar should again.... it's a win for me.

 

Remember how many ASC failures are due to cracked solder joints inside the ASC control module? Judging by the pictures I've seen of this problem, I'd guess that those oft-cracked solder joints are the power supply for the module's PCB (printed circuit board).

If memory serves (someone please correct me if memory is not serving), the effect of this solder joint failure is the 'ASC not available' and 'TRAC not available' being displayed, and the AMBER warning light illuminating...but nothing else of consequence happens (AFAIK).

Now, it is apparent from this thread and others that a split or loose ABS (reluctor) ring causes a plethora of trouble codes and what appear to be actual transmission failure(s) of some kind...

This has me wondering; could one test (AND temporarily bypass) this scary and confounding problem by disconnecting the plug at the ABS module in the engine compartment?

If so, it would verify that: A) this weird problem is related to the ABS system, and not a transmission (or other) problem, and, b) temporarily banish this problem with only the loss of ABS and traction control, leaving the car completely driveable (BTW, I've never had a car before with either one, so I don't miss them at all).