New Sport Owner P0761 and no 4wd

[72Rambo]

I just picked up a '99 Sport as my son's first car. 130K and overall, really clean. I figured on having some issues with a car this old with this many miles and a couple cropped up on my 160 mile return trip.


1. P0761. Solenoid stuck. However, the OD seems to function properly and it shifts through all the gears clean, either manually or automatically.... Fluid is full and clean.

2. No 4wd Hi, Lo, and I'm guessing Auto. Dash light works, front wheels don't engage. Haven't jacked it up to spin things yet. Did have the ABS light come on while I was testing things out in our snowy driveway. Light went off when I parked it and re-started it.

I've been reading a lot of posts, to the point I think I've confused myself about what the problem(s) might be. Here's what I've come up with:

P0761 this is solenoid C (if I recall) which is stuck in the open position. Could be a bad valve body gasket, the solenoid itself, or...? What I don't understand is why it's throwing a code when everything seems to be functioning as intended.

No 4wd. Lots of possibilities here, unfortunately... Shift motor, GEM, fuse (could it be that simple?), internal issues....

What I could use help with is where to start! I've owned 4wds for 30 years and I think I have developed some decent mechanical skills, but diagnosing a problem is half the battle. I don't want to just throw parts at this thing. Any advice would really be appreciated.

BTW, great forum. Can't believe the amount of information! It's a little overwhelming.

 

[PopRichie77]

Your 99 has a 5R55E trans, it is a 5 speed (5th being OD) with a lockup torque converter. From a dead stop with slightly heavy on the gas there should be 6 shifts with RPM drop for each. It is easy for some one not familiar with the shift pattern to miss one of the shifts and think all is working ok.

 

[72Rambo]

Thanks, I was planning on another road test today in order to count the shifts to be sure. Any danger of damaging the tranny by continuing to drive with solenoid C stuck? It's a teenager's car and isn't going to see much more than some around town use for quite a while. I'm more concerned about no 4wd, which is one of the requirements we had for a first vehicle.

 

[PopRichie77]

When the OD light flashes the computer goes into what is commonly called limp mode, it now starts in 3rd gear from a dead stop instead of 1st, it also raises the hydraulic pressure, which makes the remaining shifts harsh, it is designed to be driven to where repairs can be made. Driving it like this with a heavy foot could cause damage.
As for the 4X4, the ABS must be working for it to function in Auto. 4X4 high is activated by the GEM which applies a electro magnetic clutch in the T case. 4X4 low is is a gear change done by the shift motor. 4X4 high can be selected any time. 4X4 low requires the truck to be stopped and the trans put in neutral. Check all fuses related to 4x4 including the ones under the hood. Also check that the T case wiring plug is properly plugged in.

 

[72Rambo]

My gut tells me that the t-case problem is most likely electrical, rather than internal since there are no bad noises while driving. I plan to start checking fuses today after it warms up outside. I have a Jeep project in the garage that takes up my work space What about loose vacuum connections? I have a Chilton's which is of no help at all for the driveline. Hundreds of pages with maybe a total of 12 devoted to the tranny and t-case combined. It basically says to take it in for repair

As for the P0761, there is no harsh shifting whatsoever and it is definitely not taking off in third gear. The OD light goes off and on normally and it downshifts when the button is pushed. Acceleration is smooth and it doesn't require a heavy foot to get it off the line like a third gear start would. We owned a 98 XLT for several years, and to be honest, I don't remember it "feeling" any different than this one. But, if the CEL is on and it gives a code, something must be up.

Glad my son has about three months before he gets his license. Gives us time to work all the bugs out.

Thanks for your input.

 

[PopRichie77]

The CEL light is for engine problems. When the OD light flashes on and off there is a Trans problem. P0761 was generated by the trans and at that time the OD light was flashing. Turning off the key will reset the computer and stop the OD light from flashing, but the trans code will remain. The computer only goes into limp mode when the OD light is flashing. Clear the code and drive for several miles and see if it comes back. The Code can be cleared with a scanner or by disconnecting the battery for an hour or more.