Just about one year ago, I had a problem with no reverse, and the message on my DIC said "Shift Range Inhibited". http://www.dieselplace.com/forum/showthread.php?t=32252

Well, last month, I had the same problem and got the same message. I took it back in for another round of diagnostics, showed them their own receipt from last year's "repair", they took it in to run the codes and, after consulting with GM, they informed me that there was a different sensor that needed to be ordered. This morning, I took it in to have that sensor installed and, a short time ago, they called back to let me know that the new sensor, recommended by GM, didin't work!

They followed up this service call with another conversation to GM, and now inform me that they will have to pull my transmission to effect repair! Although the message reappeared last month almost exactly a year after the problem was first corrected(?), it's only occured that one time over that one year period.

Given the fact that last year's sensor replacement didn't solve the problem, this year's GM recommendation for a different sensor replacement didn't solve the problem, GM's latest recommendation to pull the transmission seems like a rather radical solution to me. Does it sound that way to anyone else???

Had the exact same problem. Truck was in the shop anout three times. Driving everyone crazy, most of all me. The obvious swab was the NSBU switch, but that didn't solve it. Finally, the electronics guru figured out that it was a switch in the ignition system. A $16 part solved all my problems. I am not at my house now, will be back in a couple of days. If you want, I can pull the receipt and give you the part number. Good luck.
Dennis

does it do it at totally random times? When its cold? Hot? In 4wd low?

I dont mean to insult your intellegence/driving skills, but you are coming to a full stop before you shift between reverse and drive right? :)

reason I ask that is because the Ally will automaticall go into neutral/limp if you shift between gears too fast and/or arent fully stopped (to protect itself)

Well, first, let me apologize to DuraDen and DURAtotheMAX for not responding to your thoughts and comments sooner. When I started this thread, I thought I had set it up for email notification when there was a response, but...NOOO!! I was away and had left strict instructions to be notified if any emails showed up from The Diesel Place. Although I thought it odd, when no emails arrived, I thought no one had responded. Sorry!

Dennis (DuraDen)-That's an incredibly generous gesture on your part. I'm only hoping that my problem could not have been solved that easily.

DURAtotheMAX-The problem has only recurred for me the one time in the past year and it was while on was on an errand to town. I had driven about 5 miles, the truck was warm and in 2WD. As to my driving habits, no insult taken! I'm always careful to come to a stop before shifting. While it was at the dealer's, the tech also did get the problem to occur on two different occasions.

Anyway, the reason I came back to the thread today was to update anyone who might be interested on the solution that the dealer came up with in consultation with GM. The truck spent the last week at the dealer's while I was away and, last Wednesday, they pulled the transmission! After waiting for some parts, they put everything back together and I got it back today.

Although I don't understand most of it, here's the report that came back as part of the receipt:
"Connector and pins OK. Renge(?) switch parameter flucating(?), replaced and adjusted NSBU shifted OK, went to go to reverse and range inhibit came on. Was unable to snapshot. Contacted TAS case #0000000, was instructed to remove trans and inspect pump, F(?) or strocked(?) converter valve RDI trans found pump converter fill valve bore scored. Replaced valve, OHMED(?) all shift solonoids and wiring replaced solonoid G out of spec Reinstalled trans perfo(?) RM fast adapts relearn, road tested OK."

I'm not sure if some of the items I've questioned above are spelling errors or technical terms with which I'm just unfamiliar. At any rate, when I picked it up, the tech asked me about whether the truck sits for several days at a time. When I replied that it often sits for several days, and sometimes sits for a week at a time in-between trips, he seemed reassured that, together with GM, they had solved the problem.

Frankly, I'm not so confident that it's solved and it seems like a pretty serious solution for such a seemingly minor and infrequent problem. The only reason I went ahead and let them do it is because it was covered under warrantee. If I waited, it would not have been.

For what it's worth, that the story! Thanks again to Dennis and DURAtothe MAX!

If the range inhibit occurred after the vehicle sat for several days converter drain back would likely be the cause. However, in your case I believe you said it happened while you were in town. This would point towards the NSBU but from the repair description it happened again after the switch was replaced.

From the repair report it looks like they replaced the converter flow valve, which could have caused the problem you described if it got hung up in the bore. Stuck valves can be are very difficult to diagnose. They can operate weeks or months with no problems, act up once, and then have it never happen again. The G solenoid that modulates main pressure was also replaced but that likely didn’t have anything to do with your problem.

Machinator-I appreciate your input into this situation. Based on your remarks, I'm more hopeful that the tranny wasn't removed needlessly! Thanks!

I had the same problem last november. Happened to me twice, backing up no less. Nothing happened again until a couple days ago I was accelerating on the on ramp to I-75 and when it went to shift into 5th, it hesitated and went into limp mode. Took the truck in the next day and am still waiting to hear the verdict.

MADDIESEL-Never had my problem while rolling down the road; only shifting into reverse from a stop. Hope you'll be able to solve yours without ripping out the tranny!

Has happened to my 06 twice. Both times truck was at full operating temp, I was sitting still with my foot on the brake with the tranny in reverse while I was waiting for an opening to back up and the "Shift range inhibited" display popped up. Truck still reversed normal and when I shifted to Drive the display went back to normal and everything worked the way it was supposed to. I dunno.

GMCTRUCK-So, you got the message in the DIC, but no actual failure to engage into reverse? When I get the message, the shifter is in reverse, but it behaves as though it's in neutral! Go figure!

Now that I think about it, one of the times it was engaged then actually disengaged reverse. I went to Park then back to reverse and everything was normal. All I know is my 03 with the ZF6 never did this.

that happened to me once, popping out after in gear. I didn't have it gear fully. It slipped back out and the message popped up.

Go all the way back to what Dura-Den posted at the beginning of this thread.
This happened to my truck as well. I took it to the dealer where they replaces the NSBU switch. No help. It seems that the TCM is looking for a specific voltage at the time of moving the gear shift lever to a particular gear. They couldn't find the problem and called me to pick up the truck. When the tech brought the truck out guess what happened? You got it "SHIFT RANGE INHIBIT". They did a check through the ignition switch with a Tech II and found that the prescribed voltage wasn't getting through. He replaced the ignition sw and all is well. That was two years ago and not another problem.
Just a suggestion.:grd:
Denny

Just happened to me the other day i was at the store started her up. Put in R to go backwards and got the message went to park and back to reverse and every thing worked fine.

Mine has done this a couple times too. So what would you'll say is the fix? I fixing to leave for Co. in a few weeks. Would hate for it to break down up their. Maybe it's something I can replace or fix.
Thanks

EEEZY

Here is the ing switch # if you need it. 15242754. They cause all kinds of strange things. Something to do with varying voltage to different components(yada yada ) The Envoy/trailblazers are famous for this.

Hope this helps

Rider