Hi Everyone I am trying to work out the bugs on Red, my 2nd XJR. there are several, but the one I'm the most concerned about is the shifting problem. It has no 1st gear, or 4th gear. The check engine light and the transmission fail light are on and the code is (i think) "0753 shift solenoid A, electrical". Of course it has the gm 4L80E gearbox,which is supposedly as tough as nails. So I got both shift solenoids, and a new filter, some Red Line trans. fluid that is specified for this gearbox. today I drained and dropped the pan. it has some very fine particles in the bottom, stuck to the magnet,the fluid was red, but had a slight odor,not really burnt but stinky. It looks as if someone has changed the shift solenoid A before. The wires looked okay, but the clip that holds the wire to the solenoid on had the holding tabs broken off. When I replaced it I used a small zip tie to hold it on. I put it all back together, but it was dark when I finished so I will put the fluid in in the morning. One question that I have is, how do the solenoids even work at all without shorting out when the contacts are immersed in oil, which I'm pretty sure is conductive. Am I missing something? Anyway, I tested both of the solenoids that I took out by charging up the two terminals with 12V and they both click, as if they are working. Maybe I am barking up the wrong tree? There is another somewhat troubling part to the story... When I drive it, the fuel consumption readout is way off, to the point that when the car is moving at 10 mph, the computer is saying that the car is getting 65 mpg. when the car is sitting still, and idling, it's getting 199mpg! Is this possibly a sign that the computer or transmission control module has got a problem? I will report back after the fluid goes in and I give her a test run. until then, any info about the rest of the problem would be helpful and greatly appreciated, thanks, Mike

 

Hi all, Just wanted to up date this thread, Still hoping some transmission guru will chime in and help me to solve this problem. I added the fluid today, and cleared out the codes but before I had it backed off the ramps the transmission fault and check engine codes were back on. took it for a ride, still no first gear, strong second, smooth shift to third, but when I put it into drive, no change in rpm or speed. the difference between 3rd and 4th is that in 4th when I let my foot off the gas, the RPM's drop to an idle while the speed coasts along with no resistance. slide it back into 3rd and the RPM's go back up to normal for that speed. I guess I need to start looking for a wiring fault between the transmission control module, and the gearbox, does anyone know where the TCM is? and what it looks like? Mike

 

If the trans mount gets weak the trans moves around enough to stretch and break the wiring at the connector to the trans....fairly common issue.

Couldn't hurt to remove the connector and take a good look at the wiring and pins


Cheers
DD

 

Hey Doug, thanks for the advice, so today I brought it to a local shop, they unplugged the connector from the trans. plug and pins look fine, next lowered the TCM from under the glove box, And tried to do some continuity testing between the TCM connector and the trans. connector. they messed around for 4 hours, while I pulled my hair out. They pretty much determined that there must be a broken wire somewhere between the two. actually since they could get little or no continuity between any of the pins(supposedly) there must be several broken wires. This seems unlikely to me, since there is only the one fault code. now he says I need to schedule another appointment when he can spend some time tearing the whole center console section out to expose the wire harness between the two..... I told him that I would probably take care of it from here. Just don't know what to do... I guess start over doing what he was trying to do..... wish me luck!