In most cases, people do not realize that most Jaguar transmission problems, such as delayed shifting, harsh shifting, or a car that won't shift or go in gear, can be caused by low transmission fluid level, which should be corrected immediately. Known problems that affect Jaguar vehicles include automatic transmission valve body and torque converter failure, which cost a lot more to fix.
This guide will provide helpful tips that will help you troubleshoot a Jaguar transmission yourself, along with a list of common problems that affect Jaguar transmission and possible causes.
Common problems with Jaguar automatic transmissions:
- Won't go in gear
- Transmission won't shift.
- No reverse gear
- Stuck in gear
- Won't change gears
- Transmission jerks when changing gears
These are the most likely symptoms that you will experience on a Jaguar vehicle. With that said, it doesn't mean that every Jaguar vehicle will have transmission problems. We often see Jaguar vehicles with well over 100,000 miles.
The most common issues that cause Jaguar transmission problems:
- Low transmission fluid level - Low transmission fluid level start with erratic shifting, and in some cases, the check engine light may also come on due to fault codes such as P0700, P0730, P0706, or P0783.
- Torque Converter - Can cause the transmission to slip in all gears or shudder.
- Worn Bands - Can cause delayed shifting, shifting at high RPM, harsh shifting, no gear at all, no reverse.
- Shifter Module - A faulty shifter module or shifter cable can cause the transmission to get stuck or not go in the selected gear.
- Valve Body - The valve body is very complex. Depending on failure mode, it can cause limp mode; the transmission may not shift at all or cause harsh shifts at startup.
- Vehicle Speed Sensor - If your Jaguar has developed harsh shifts or is stuck in emergency mode (limp mode), the vehicle speed sensor (VSS) may be the problem.
- Brake Light Switch - A faulty brake light switch can cause the shifter to get stuck in Park.
- Low Battery Voltage - In some cases, the low battery voltage can cause the Jaguar gearbox fault to show up on the instrument cluster.
- Transmission Control Module (TCM) - Software issues with the TCM can cause erratic shifting or downshifting issues. Jaguar transmission may shift too late, or gears may drop unexpectedly. Call any Jaguar dealer and ask if they have a software update to fix transmission shifting problems.
- CAN Network / Wire harness - Damaged wire harnesses from ECU / PCM to the transmission housing can cause shifting problems. For example, your Jaguar may not shift at all or go in gear due to a CAN network problem. Typically when a CAN network issue is present, you may notice a number of other issues as well.
Troubleshooting Jaguar Transmission Problems
The following steps will help you troubleshoot and isolate Jaguar transmission problems. If your Jaguar is not shifting, it won't go in gear; first, you need to check the transmission fluid level first and use the recommended Jaguar transmission fluid if the level is low.
If the level is correct, the next step is to read the fault codes with a Jaguar scanner from the transmission control unit (TCU). Don't use a generic scanner.
Check Jaguar Transmission Fluid Level
- Park vehicle on level ground.
- Set the parking brakes and shifter in Park.
- Pull the hood release and open the hood.
- Locate the transmission dipstick.
- Remove the dipstick and clean it with a clean cloth.
- Reinsert the dipstick in the transmission. Ensure the transmission is fully inserted, then remove it.
- Look carefully at the dipstick to determine the current transmission fluid level. The level should be between MIN and MAX marks for the COLD (lower) markings.
- If the level is low, add transmission fluid level.
- Drive vehicle for 15 minutes making sure to select all the gears manually.
- Repeat the procedure once the transmission warm-up, but this time, the level must be between the MIN and MAX marks.
Not all Jaguars have a transmission dipstick. If the dipstick is not present, the vehicle will need to be raised on a lift, and the level can be checked via the fill hole.
Read Transmission Fault Codes
The next step is to read fault codes from the transmission control module or what is known as the TCU. To read these codes, you will need an OBD-II Transmission Scanner that works on Jaguars.
- Park the vehicle and turn off the ignition. Set parking brakes.
- Locate diagnostic port under the dashboard, driver's side.
- Plugin your OBD-II scanner, then turn on the ignition without starting the engine.
- The scanner will turn on. Allow it to communicate with the vehicle
- Select Transmission Control Unit
- Select Read Fault Codes from the menu.
Basic code readers are not recommended because they will show a generic code or may not show a fault code at all.
Check For Recalls
Check if any open recalls or Technical Service Bulletin (TSB) exist for your Jaguar that affects the transmission.
Recalls if they exist, are performed free of charge by any Jaguar dealer. To check if a recall exists on your vehicle, visit our Check Recalls page.
Jaguar Technical Service Bulletins (TSB), on the other side, is specifically for the transmission Transmsimon control unit software. TSBs typically program the shift solenoids, which then makes the transmission shift quickly or later depending on the issue.
Common Jaguar Automatic Transmission Problems
Below is a list of most likely problems that you may experience on a Jaguar with automatic transmission. It is important to find out which transmission is installed on your Jaguar. These problems do not affect all transmissions.
Delayed gear shifts or missing 4th and 5th gear
Jaguars with a Ford sourced 5R55N 5-speed automatic transmission can suffer from intermittent or constant loss of 4th or 5th gear.
It is also possible for other gear changes to be erratic or delayed. Initially, the problem will only occur when the car is cold but can get worse with time. This issue will trigger a check engine light, so there will be corresponding codes stored in the DTC memory.
Possible causes and solutions
- Broken spring behind the 4th pre-stroke valve, resulting in an inoperable valve. This will prevent the 4th gear from engaging and trigger 0734 and P0735 codes. As this is a very common problem, there are upgraded replacement kits that permanently solve the issue.
- Sticking solenoid valves or worn valve body. As a result of insufficient fluid pressure, the gear changes can be delayed or harsh, especially when cold. This will rarely result in a check engine light.
Delayed gear shifts or limp-home mode
Jaguars with a Mercedes sourced 722.6 5-speed automatic transmissions can suffer from issues that range from harsh and delayed gear shifts to gear slippage or even going into limp-home mode.
In most cases, these symptoms will be intermittent and trigger a check engine light, so there will be a corresponding error code stored.
Possible causes and solutions:
- Faulty conductor plate, which holds the solenoids and connects them to the TCU. When the conductor plate is faulty, it causes communication problems, which results in improper solenoid operation. This is a well-known problem, and there are numerous aftermarket solutions. The 722.6 conductor plate can be replaced without removing the transmission from the vehicle.
- Worn or faulty valve body solenoid. Sometimes, the problem can be damage to the internal wiring.
Harsh or failed gear changes
Jaguars equipped with a 5-speed ZF5HP automatic transmission have several common weak points that will cause shift issues. They range from delayed or harsh shifting to failed gear engagements.
This will affect lower drive gears and, in some cases, reverse. There will be no check engine light or other symptoms present.
Possible causes and solutions
- Failed transmission fluid pressure regulator, which ensures a correct hydraulic pressure. This regulator has springs and valves that wear out and cause a pressure drop. When this happens, the gear changes become harsh and erratic, which can cause additional damage to the transmission. Although rebuild is possible, replacing it with an upgraded unit is a better solution.
- Worn F-clutch piston, which is responsible for the engagement of reverse gear. With time, the seal on its body wears out, which causes a pressure drop.
Shift flares and delayed gearshifts
All-wheel-drive X-type Jaguars that use a TF 80 6 speed automatic gearbox can experience shift flares during acceleration and delayed downshifts when braking and stopping.
Initially, the problem is only present when cold and while accelerating slowly, but gets worse with time. In most cases, there will be no other symptoms.
Possible causes and solutions
- Deteriorated and dirt transmission fluid and filter. On any high-mileage car, check the service history first. As this transmission is considered to be 'sealed for life,' there is a chance that the transmission fluid was never changed. If needed, perform a detailed flush using only the approved transmission fluid.
- Worn bores inside the valve body. The resulting pressure drop will cause various shift issues. Replacing the whole valve body is the only solution, but because this is a well-known problem, many specialized workshops sell rebuilt ones.
Gear slippage when shifting into 4th gear
Jaguars that use a ZF6HP 6-speed automatic transmission can suffer from a very noticeable gear slippage when upshifting from 3th to 4th gear.
As a result, the gear change will be delayed, harsh, and may even send the transmission to fail-safe mode. When this happens, the check engine will come on, and there will be a code stored in the DTC memory.
Possible causes and solutions
- Worn E-clutch or broken E-clutch drum. As this assembly is responsible for the engagement of 4th gear, any excessive wear will result in incorrect gear speed ratios and prevent them from engaging. Rebuilding the E-clutch assembly is the only solution.
- Clogged, worn, or damaged solenoids. If the fault is electrical, it may trigger a check engine light. Mechanical issues and clogged solenoids will rarely result in a check engine light.