Hi,

I thought I would share this "fix" with you folks. My 2000 XRJ has had intermitant computer issues that would put it into RP and show any variety of error messages. In the past I could usually get it to reset and the problem would go away for a while, but it has been into the dealership several times over the years for this. I think all they did was clear the codes and charge me $$$, never actually fixed anything.

Recently it showed the transfault and went into RP. Unlike in the past, it didn't fix itself, and after about a month of fooling with it (battery charge, battery disconnect, ground strap checks, fuse checks, relay checks, etc) I gave up and towed it into an ind. mechanic.

I recalled the dealership mentioning a transmission speed sensor, and mentioned that to the mechanic. He did some research, then reset all the codes (he said there were many random codes along with a few valid).

He says that sometimes the position sensor on the gear selector gets dirty since it is usually only put into park, R & D. His repair was to cycle the gear selector (with the car off but the key on) through all of the gears about 25 times - gentle but firm. Between the code reset and the shifter klug, the problem has not resurfaced for a couple of months now (the car is actually reliable at the moment!).

I suspect that if the position switch is gummed up it occaisionally sends mixed/incorrect signals to the computer, which will eventually cause the error messages/RP mode. I think this accounts for some of the random error messages too.

It has/had another issue; go to start the car, turn the key, everything lights up as normal but no crank of the starter motor. It has done this numerous times, but eventually it cures itself and the car starts.

While looking for the relays on the above effort, the car did its no-start routine. I randomly banged on the top of the front left relay box, and moved the wires around underneath it. Turned the key and all good. It's done that 5 or 6 times since, and each time I fool with the relay box it starts. Hasn't done it again in several weeks, and the only thing I have touched is the front left relay box. Of course, I have no idea what that box controls...

I will take it apart and clean up the connections when I get some time, but hopefully these ideas help somebody out there...

 

A large number of the gremlins in these cars seem to trace back to dirty or corroded connections and switches.

 

The relay functions will be listed in the vehicle maintenance booklet around the fuses page.

Weak or sticking relay?

Of course, it could be that when you get out to bang the box, and get back in, you are moving the gearshift again ... resulting in the neutral start switch moving into a slightly different position.

 

I am 100% convinced the no-start issue and the transmission fault issue are completley seperate, although I had figured that the no-start was possibly a function of the gear position sensor and did explore that. Because the no-start is so intermitant it is really tough to diagnose. Knowing roughly where the connection issue might be would be hugely helpful, so my fingers are crossed that I happend to stumble across it.

I do think the gear shifter cycling along with the code reset might be helpful, total cost to do that was $162.00 including his research time. Cheapest Jag repair ever...

 

Good post, I believe it will help others as well .

 

Sounds great, I'm gonna go try it right now. Fingers crossed. It looks like we have twinkies BTW.