1996 xjr6 where to start with this error code? check harness and if not finding any broken wires remove pan and change shift solenoids? car is basically stuck in gear and wont change gears untill way up in the revs. and when it was driving on the motorway way the gears kept changing up and down up and down. also the gearbox mount rear bush isnt even there anymore and there is alot of play in mounting without that bush. so where do i start? do i need to remove the plate held in with 3 nuts at the bottom of the mount to even to get at the plug on the gearbox? any help greatly appreciated.

 

I just had this issue recently on my XJS with the ZF 4HP24 transmission.

Took it to a tranny shop, they allegedly tested the solenoids and told me they tested well. Recommended swapping out the tranny ECU, which I did. No change.

Took it to a Jag shop and they told me that it would be costlier for them to troubleshoot the transmission than it would to swap out the transmission valve body with one from a 97 XJ6. No issues ever since.

 

If your mystery car is actually the SuperCharged version, then you have the GM gearbox.(not ZF)

 

sorry guys forgot to mention 1996 xjr6

 

We’ll forget my response then.

you should create a signature to avoid this confusion in the future.

 

Gday Paddy,

I have an X305 V12 with the same transmission as your XJR, the GM 4L80E, and it needed a complete rebuild recently due to continually degrading performance which started years ago and showed up initially as a shift solenoid problem.

A valve body rebuild or replacement would be way cheaper than a full rebuild.

This following info might be helpful.

Cheers,
Jeff.

AFL Valve.

1993 to 2018 General Motors vehicles equipped with 4L60E, 4L65E, 4L70E, 4L75E and 4L80E automatic transmissions often wear out the actuator feed limit (AFL) valve bore. As a result, inadequate pressure rise and shift solenoid feed oil loss can occur. This can cause trouble codes, wrong gear starts, falls out of gear and clutch plate burn-up.

The purpose of the actuator feed limit valve is to limit the pressure going to the actuators (aka shift solenoids). The AFL valve spring is calibrated to prevent the pressure from ever exceeding a predetermined pressure, no matter what the main line pressure is. This is necessary to prevent more fluid from being fed to the solenoids than they can physically exhaust and to limit the maximum line pressure output.

On one hand, if the pressure feed to the ON/OFF shift solenoids is higher or lower than intended, the shift valves controlled by those solenoids may not do what they should. For example, too much pressure could flood the shift solenoids, making them act as mechanically stuck closed solenoids. Alternatively, not enough pressure could make them act as mechanically stuck open solenoids. As a result, the transmission can have wrong gear starts, or fall out of gear.

On the other hand, for pulse width modulated (PWM) solenoids like the line pressure control solenoid (PCS), if the feed pressure is too high or too low, the consequences can be detrimental. The PCS output controls the line pressure based on the calculated load from the computer. Consequently, if the AFL pressure feeding the PCS solenoid is too high or too low, the line pressure output will also be too high or too low. As a result, the transmission will either slip and burn frictions, or have hash shifts.



PWM/TCC Valve

1991 to 2013 newer General Motors vehicles equipped with 4L80E and 4L85E automatic transmissions often wear out the torque converter clutch (TCC) regulator valve bore in the valve body.

The TCC regulator valve function is to regulate the torque converter clutch apply pressure. The computer varies the pulse width modulation of the TCC PWM solenoid, which regulates the apply pressure of the lock-up clutch. Because of the constant PWM solenoid induced oscillation, over time, excessive wear of the bore occurs. As a result, the computer loses the ability to control the lock-up clutch apply rate and slip rate properly due to the loss of TCC apply pressure.

 

Great thanks for the info even though im a little bit more paranoid now that im going to need a costly rebuild. but all i can do right now myself i suppose is check the wiring and then the solenoids and then the valve body kit and after that i think it could be cheaper pick up a used tranny and torque converter than a rebuild. i think these are the steps i will take if anyone has any other sort of intake id be grateful of your knowledge with the 4l80e usual issues thanks all

 

G'day Paddy,

My problem showed up many years ago as a shift solenoid problem when it was really a dodgy AFL valve and eventually deteriorated to the point where I needed a full tranny rebuild.

If I'd had the problem fixed back then it would have more than likely been just a valve body rebuild rather than a full tranny rebuild.

The tech at the place that did my rebuild said that the dodgy AFL valve eventually causes wear in most of the other transmission components over time and so some fifteen years later the box needed to be rebuilt.

There are inexpensive AFL valve repair kits available but I would not be doing the job myself, better to see a transmission shop.

The Jag transmission is an adaptation of a General Motors 4L80E which is used widely in SUVs and smaller trucks so there should be plenty of places that could do the work.

Cheers,
Jeff.