Question about Jaguar XK8

1 Answer

"Transmission Fault" warning light came on and car's transmission went into limp mode and transmission functioned poorly.

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Brigadier General:

    An expert that has over 10,000 points.

  • Master
  • 8,619 Answers

Hi!

In the event of “Transmission Fault” following things need to be checked

Gear shifting: Driver gear selection is transmitted from the gear selector lever by cable to a lever fitted to a selector shaft in the transmission casing. This shaft moves the manual valve and the rotary switch. The rotary switch signals all gear positions except D to 4. A separate switch in the driver gear selector mechanism detects movement of the selector between D and 4. The communication of driver gear selection to the TCM is made by the rotary switch. Gear shift points are selected by the TCM in response to output speed, engine load, selector position, accelerator pedal position and driver mode selection. Driver control of the shifting is via the selector lever, throttle pedal position, kick down switch and mode switch. Two shift modes are available, sport and normal, controlled by the driver from a switch on the gear selector surround. During kickdown, gear upshifts occur at 6800 RPM engine speed.

Mechanical Description: The unit is an oil filled-for-life system therefore no dipstick is fitted to the transmission. A filling/level plug is located at the right-hand side rear of the casing for service oil level checking and replenishment, if required. To achieve effective cooling, the oil is pumped from the transmission casing at the front left-hand side of the casing to the car mounted oil cooler. The oil is returned from the cooler to the inlet connection on the front right-hand side of the casing. The cooler is a plate-type design made from aluminum and is located in the car radiator outlet tank. To detect changes in oil viscosity which occurs as the oil temperature changes, an oil temperature sensor is located in the unit casing sump. Also located in the transmission casing are the input shaft speed sensor (turbine speed) and output shaft speed sensor (vehicle speed). The torque converter is a lightweight unit which, because of its low mass, improves engine responsiveness. The torque converter bell housing is bolted to the transmission casing. Mounting of the transmission is conventional by bolting the torque converter bell housing to the engine. The rear extension housing is bolted to the transmission casing and forms the rear engine/transmission mounting point. It also carries the output shaft oil seal. The electro-hydraulic module contains three solenoid valves and five pressure regulators for gear shifting. Each of the three solenoid valves control the flow of transmission fluid to the selected clutches. One pressure regulator serves as master pressure control for the entire system and one is used exclusively for torque converter clutch lock-up operation. Replacement transmission units are shipped complete with the torque converter and housing, extension housing, coupling flange and rotary position switch. They are also fully filled with 10 liters (2.645 US. gals) of oil. Consequently, when undertaking a transmission replacement, oil replenishment should not be necessary. The exterior of the transmission is coated with non-drip corrosion protection oil, which must not be mistaken for an oil leak.

Electrical Connections

Bayonet Connector: A round, 16-pin, bayonet electrical connector is fitted at the rear left-hand side of the transmission which communicates with the 5 pressure regulators, 3 shift solenoids, oil temperature sensor and the input and output.

Automatic Transmission: The five-speed automatic transmission is designed to accommodate different driving styles and automatically adapt shift patterns to suit varying road/driving conditions. The switch marked .S. on the .J. gate surround enables the driver to select either normal .N. or sport .S. transmission modes.In addition to the .switched. Transmission modes (.N. and .S.) the transmission control module will select shift patterns to suit specific conditions. These are:

Cruise Control. When cruise control is operating at set speed the transmission selects a shift pattern to suit cruise control operation.

Traction Control. When traction control is switched ON and the system is activated, the transmission selects a shift pattern to suit traction control conditions.

Gradients. When the vehicle is being driven on roads with uphill gradients, the transmission selects a shift pattern designed to make better use of engine power and aid engine cooling.

Note: Under the conditions described above, the relevant transmission mode will override the .N. or .S. modes selected by the driver. When such conditions no longer exist, e.g. Cruise Control switched OFF, the transmission will revert to the shift pattern previously selected by the driver, i.e. .N. or .S..

Please do accept this solution and revert for further assistance.


Thanks

Rylee

Posted on May 30, 2009

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Hi i have a 2009 diesel x type jaguar when first starting car i have gearbox fault and car goes into limp mode but after 10 minutes driving when you switch off and restart car everything is fine


When the limp home is engaged by the processor a fault code or codes is set in memory, it may be a Transmission code or engine fault code. You nee it tested with a full function scanner, a code reader will not read the transmission faults.

Jan 19, 2017 | Cars & Trucks

1 Answer

How can you tell if a new gearbox is needed other than a Ecu which has been replaced


have the fault codes read first
if the car is moving in limp mode with no obvious noises or problems , replacement of the box is a total last resort
light on the dash and limp mode can be transmission or engine or both but the fault codes will show the problem area
The ECU -- engine control unit or ECM --engine control module gets messages from the transmission control module ---TCM--and that TCM controls solenoids and servos , vss and other items that if faulty will put the car in limp mode
read the fault codes

Sep 20, 2016 | Cars & Trucks

1 Answer

1996 Dodge stratus es automatic wont shift outta low gear .is this a sensor issue?


probably not if it is limp mode
the ECM puts the car in limp mode to prevent serious problems in the engine or transmission
could be no coolant, sump oil , transmission oil etc
run the fault codes and find the reason for the mode

Feb 18, 2016 | Dodge Cars & Trucks

1 Answer

Oil light is on and engine in limp mode


check the oil level in the sump, coolant level, coolant temperature (overheating), transmission oil level if auto. The limp mode is energised by any number of sensors that register a fault that is detrimental to the engine/ gear box. Run the fault codes and repair any faulty units . Reset the CPU with a scanner .

Jul 02, 2014 | 2005 Holden Rodeo

1 Answer

Toyota yaris in limp mode with p0705/stability control light illuminated


EOBD II Error Code: P0705
Fault Location:
Multi-Function Transmission Range Switch - Malfunction (PRNDL Input) - Implausible Signal
Possible Cause:
Wiring/Connectors from/to Multi-Function Switch faulty.
Multi-Function Switch faulty.
Engine control module (ECM)/Powertrain control module (PCM)/Transmission control module.

Possible Solutions:
Check Wiring/Connectors from/to Multi-Function Switch.
Check Multi-Function Switch.
Check Measuring Value Blocks.

Apr 04, 2014 | Toyota Yaris Cars & Trucks

1 Answer

Transmission only operates in one forward gear,1991 JKG with 4.0 engine


Hi, are there any warning lights on the instrument panel, car maybe in "limp home mode" can be a number of items mainly poor running or sudden engine cut out such as a faulty crankshaft sensor. Any other symptoms?

Feb 20, 2013 | 1991 Jaguar XJ6

1 Answer

Gear box fault warning light


that gear box fault light comes on, its pretty much game over for the transmission. It only a matter of time before performance of the transmission gets worse and worse. BUT that transmission is VERY easy to replace, i would check out a few trustworthy independentshops to give you a better price! I am usually a die-hard dealership, having been working at this jaguar land rover dealership for the last 2 years, but you are pretty much for sure going to be a cheaper price on the labor and like i said it is a pretty easy task.

My only precaution MAKE SURE IF YOU GETTING A USED TRANSMISSION THAT YOU GET SOME TYPE OF WARRANTY ON IT. Too many times have I seen customers loose thousands of dollars paying someone to put a used engine or transmission and have it fail almost right away

Sep 06, 2012 | Jaguar Cars & Trucks

1 Answer

Replaced trans, now car is stuck in limp in mode


MCARTER859: check the connections where the transmission harness and engine room harness come together. Unplug them and reconnect them I have run into more than one case with the same symptoms as yours which ended up being nothing more than poor connections.
CROSS YOUR FINGERS1

Apr 21, 2009 | 2003 Mitsubishi Eclipse Spyder

1 Answer

Can a toxic fume filter send a megane 2 into limp mode


Not directly, but the engine ECM and Transmission TCM are connected, so if the engine is running badly, this will effect on the transmission, and may confuse the TCM and make it go into limp mode.
Hope this helps

Feb 14, 2009 | 2000 Porsche Boxster

1 Answer

Transmission locked up, felt like it was stuck in second or third gear. not shifting. shut engine off and restarted , shifting properly now. what causes this.


It was a temporary fault that put the car into limp mode (a safeguard operating condition designed to protect the transmission in case of serious failure). Sometimes a transient fault can occur, and the car goes into limp mode just to be sure it's not for real. Shutting off and restarting the car is the usual way to clear the fault and return the car to normal operation - if the problem was real, the car would've stayed in limp mode after restart, or gone into limp once you started driving again. I wouldn't sweat this one, since it went right back to normal operation.

Aug 02, 2008 | Mercury Milan Cars & Trucks

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

503 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jaguar Experts

Colin Stickland
Colin Stickland

Level 3 Expert

22246 Answers

yadayada
yadayada

Level 3 Expert

76848 Answers

SPEEDY CAR WORK SHOP...

Level 2 Expert

489 Answers

Are you a Jaguar Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...