Fault code P1793 (gearbox fault) - Jaguar Forums - Jaguar Enthusiasts Forum

XK8 / XKR ( X100 ) 1996 - 2006

Fault code P1793 (gearbox fault)

Thread Tools Search this Thread
Old 12-27-2008, 06:41 AM
Posts: n/a
Default Fault code P1793 (gearbox fault)

Hi Can anyone help. We have a problem with our XK8. The dash comes up with a fault saying" gearbox fault " and something like "traction control error" and"......

We had the fault checked by local garage which showed a fault code P1793.

Does anyone have a similar problem and know what the problem might be and resolution.

It has been sugested it might be corrosion on the pins somewhere.

Would be grateful of any input.

Thanks , Nigel
Reply With Quote
Old 12-27-2008, 12:19 PM
2000blackxkr's Avatar
Senior Member
Join Date: Aug 2007
Location: Battle Ground Washington
Posts: 258
Thanked 25 Times in 10 Posts
Default RE: Fault code P1793 (gearbox fault)


This is what i found in my pdf diagnostic info for that code.

System Voltage – P1793, P1798
A permanent supply is used to maintain a battery backed 'memory'. Should this supply be cut, due to battery disconnection perhaps, the 'adaptive shift' values will be lost. This will result in a small reduction in shift quality for a period until the adaptions are 're-learned'.
The TCM monitors the supply voltage and will log a Diagnostic Trouble Code (DTC) if the voltage is not between 7 and 16V for more than 300 ms whilst the engine speed is greater than 1600 rpm. This fault is unlikely to be caused by a failure within the TCM and as such the vehicle harness and fuses etc. should be checked before the TCM is condemned.

I dont know what year your car is, but that applys to "ZF 5HP24" XK8 4.0 L N/A 1997 to 2002 model year

good luck. keep us posted on your repair.
Reply With Quote
The Following User Says Thank You to 2000blackxkr For This Useful Post:
elic9 (02-12-2015)
Old 02-12-2015, 09:21 AM
elic9's Avatar
Senior Member
Join Date: May 2012
Location: El Paso, TX
Posts: 108
Thanked 2 Times in 2 Posts
Unhappy gearbox fault

I also had a reading of gearbox fault, I believe it is the transmission, it has to be re-built or replaced. Does anyone know how much that would cost?
My car is sitting at my home and, it will not start anymore, I have enjoyed driving my car for two years and, am having a hard time getting rid of it.
Offered only 800.00 dollars..I was told also it could just be the timing..
I am not sure what to do now. ; ( it is a XJ8 2002...

Last edited by elic9; 02-12-2015 at 09:24 AM.
Reply With Quote
Old 02-13-2015, 05:50 AM
larueb's Avatar
Senior Member
Join Date: Jul 2013
Location: Florida
Posts: 385
Thanked 70 Times in 49 Posts

I had my transmission in my '99 rebuilt 3 years ago for around $5,000. It lasted 40 thousand miles and broke. I am going with a replacement from a junk yard for $3,600 installed. Not happy with rebuild!
Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
iCarsoft i930 OBD-II scanner read suspension codes? philwarner XJ XJ6 / XJ8 / XJR ( X350 & X358 ) 14 06-06-2017 05:18 AM
Replaced coil, now many problems cissdm X-Type ( X400 ) 10 05-03-2016 06:02 AM
AC Compressor lock signal fault tonyforman XK8 / XKR ( X100 ) 2 09-10-2015 07:23 PM
Drive cycle for 2001 XKR help! skadmiri1 XK8 / XKR ( X100 ) 16 09-09-2015 11:27 AM

1997, 2000, 5hp24, battery, code, codes, description, dtc, due, falt, fault, gearbox, jaguar, p1793, p1798, transmission, xj8, xk8

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 07:44 AM.

JAGUAR and its logo are the registered trademarks of Jaguar Cars Limited. Jaguar Cars Limited is not affiliated with JaguarForums.com.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: