As I mention in other threads, my newly purchased 2008 H3 base (Just turned 140K MI) seems to have about half the problems discussed here recently -- and now a new one that I don't see mentioned.

Twice now in two days, I have had the following problem:

Vehicle operating normally, and warmed up. Come to a stop at a light, when I attempt to go again, it does not shift out of 1st gear - engine rev's high and top speed is about 20 (without destroying something).

Speedometer indicates 0 MPH.

I shift into neutral, and back into drive -- the speedometer comes back to life and the transmission shifts as normal. Today, I noticed that the speedometer "jumped" once to the correct speed, back to 0, and then to the correct speed again before resuming normal indication and transmission shifting.

No ECM or TCM codes related to this problem (I have a check engine light due to an unrelated known condition.)

I do not detect (feel or smell) any wetness on the passenger side floor.

I will buy a replacement transmission speed sensor (which apparently is the one that drives the speedometer) tomorrow , but I read something about a second sensor inside the transmission starting in 2008.

 

Sorry to reply to my own thread, but I did find an old thread here on HF that describes my problem exactly -- even the frequency of occurrence.

The culprit in that thread was the output speed sensor. Also called the transfer case speed sensor.

Based on the other thread, I will also inspect visible parts of the harness, and at least clean up the connector if it's not apparent that replacement is necessary.

 

Make sure the TC Speed Sensor is snug. If it backs out from proper position even just a little, it may not correctly sense speed/rotation. The harness is a good place to look and use CRC Electronics Cleaner on the connectors. Since it is an electronic part, just like all man made parts, they can fail over time so you may tray a replacement if necessary.

Good luck and let us know what you find with this problem.

 

Just wanted to post a non-update on this before thread gets too old.

I purchased a speed sensor (I guess some would call it the transfer case speed sensor) from a local auto parts store. The speed sensor remains in the box on my kitchen counter.

I only had the no-shift, no-speedometer symptom once since I last posted in this thread, and it hasn't happened again even after hundreds of miles driven, including several hour+ trips to other towns, hot Florida days, and being in stop+go traffic.

I still feel like I have to look at the speedometer call out "airspeed is live" every time the traffic light turns green. (Pilots will get that, and yes -- I know it's indicating ground speed, not air speed.)

For now, the new sensor will remain in the box, and next time I'm under there, I will de-mate and clean the connector with my "secret sauce", and gently try to tighten the existing sensor.

If there is further or increasing miss-behavior, I'll change the sensor.

 

Now I have an actual update on this.

After this problem had not recurred for 2 months, It happened twice on the way home from volunteer service this morning. It was fine for a short drive to lunch, but on the way back it happened again at least 3 times. 2 of those times was within about 1/2 mile from the house, and in these last 2 times, I was able to get a speedometer reading, and resume normal shifting by shifting into Neutral and back to drive without coming to a complete stop.

For reference, the original problem, is no shift out of first gear, and no speedometer indication.

So I figured that perhaps it was time to actually install the new part that I bought in June or July. (It's now October).

Changing the transfer case (transmission) speed sensor is very straight forward, and a great and super easy even a first time DIY repair.

Vehicle in Park, Parking brake engaged, and chocks in place for safety. If you tell people you are a good mechanic, but you fail to prevent the vehicle from rolling while you are under it, you are -flat- lying.

The sensor is located on the left side of the back of the transfer case. Looking forward from the rear of the transfer case, it is about at the 10 o'clock position relative to the rear drive shaft.

Disconnect the sensor connector by gently lifting the black locking feature, and pulling the connector out of the sensor. Loosen the sensor with a 19mm wrench (box wrench suggested).

The new sensor should have an o-ring installed, so no tape or sealant should be needed. Keep the tip of the new sensor clean and free of fingerprints. Clean the area around the hole in the transfer with a clean rag.

Begin threading the new sensor in by hand. The original and the replacement parts were plastic on my H3. Cross threading = Bad.

Tighten the new sensor with the 19mm wrench. I made mine slightly tighter than I normally would for a plastic part, but I wanted to make sure it was fully down against the transfer case. Don't strip it or tighten it so much that is "squishes out" the o-ring.

I also sprayed both sides of the connection with a non-wax spray lubricant/moisture barrier. Inspect the purple seal on the vehicle-side connector. It should be supple, clean, and not have any evidence of cracks or damage. Push the connector onto the sensor until the plastic tab locks.


Observations:

-- The metal tip of the new sensor protrudes slightly from the plastic. On the old one, the metal tip was flush or even slightly recessed.
-- As soon as I began to reverse down my driveway, I noticed a difference. While I don't make a habit of reversing while staring at the speedometer, I had never seen an indication on the speedometer when backing at idle speed. With the new sensor, I did. When moving from a normal stop, The speedometer now indicates almost immediately, with no noticeable "jump". Previously, it would "jump" from 0 to about 2 - 5 mph every time I started off. I drove to a local parking lot and drove around for a while making numerous starts and stops -- Some shifting into neutral, and some not, but always coming to a full stop for a least a minute or so. In no case did it miss the 1 --> 2 shift or have a delayed indication on the speedometer.

Note: If your H3 has the delay or "jump" in the speedometer indication, you have this problem even if the car is driving/shifting beautifully.

 

I've had same symptom, and success with the same solution.
Intermittently, I've had speedo dipping or sticking at zero, and gearbox overrevving or not transferring power to the wheels. Speedo not working in reverse either (odd thing to look for!). I replaced the VSS Speed Sensor and car running well now. Thanks everybody! Cheap enough option to try if you're not sure ($100 part, $150 fitting).