XJ40 Transmission warning light
 

Hi,
I have had 4 beautiful Jags in my life and the latest is an XJR 100 from new but I have just been gifted the most immaculate XJ40 and the amber transmission light keeps coming on thus dropping the car into LHM. The transmission was rebuilt 6 months ago. The light will go out if left overnight and then reappears about 15-20 klm after start up. The designated fuse is ok.
Any ideas?
Rod Steley

Welcome to the forum Rod,

I've moved your question from XK8/XKR to XJ40 forum. Members here with the same model will be able to help.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

Hi Rod,

Welcome to the Jaguar Forums, and congratulations on your new immaculate XJ40! Please let us know the year and engine since these details can make a significant difference in the answers to your questions.

Since you have an amber transmission light, I'm going to assume you have a 4.0L model with the ZF 4HP24 electronically-controlled transmission. The most common cause of the transmission lamp and Limp Home Mode seems to be oil contamination on the electrical connector for the Throttle Position Sensor. The TPS is mounted on the underside of the Throttle Body, and its short harness connects to the main engine harness via a connector that is usually mounted on a bracket attached to the intake manifold elbow just to the left of the TB.

Disconnect the connector and flush the terminals in both halves with zero-residue electronic cleaner and allow them to dry or use compressed air. Reconnect and see if the problem is resolved. If not, you may need to remove the TB, pry the cover off of the TPS, or if it won't come off, drill small holes in two corners of the cover so you can insert the "straw" spray nozzle of the electronic cleaner can and flush all the accumulated oil and gunk out of the TPS.

If that still does not resolve your LHM, I'll offer more diagnostics once you let us know the year and engine of your car.

P.S. When you get a chance, how about posting some photos of the car so the rest of us can drool over them!

Cheers,

Don

yep. Once cleaned and reset, let us know if it happens again. We can then move on to the next step

I had this same issue on a 93 XJ6 with 80k miles on it. Cleaning the Throttle Position Sensor resolved the issue.