GMC C6500 automatic trans "range inhibit" light

harb57 · 05-19-2007, 04:46 AM

I have a 2001 gmc c6500 with an allison automatic trans. I have had a few things happen that I'm not sure of and hope someone here knows about.

The first and I think this is minor, was last week after the truck had sat about a month( started reguarly but not moved) I put it into drive and nothing happened---so I shifted into reverse then to drive and everything was ok.

Today after unloading the truck I got in, shifted from neutral to drive and nothing, but this time I got a "range Inhibit" light. After shifting to reverse and back to drive light went out and transmission went into gear.

What does the range inhibit light mean. Other than that the trans shifts fine when driving. This is the first truck I've had with an auto trans.

Thanks

Birken Vogt · 05-19-2007, 01:24 PM

If it is an Allison 1000, 2000 or 2400 series it could be related to the Manual Lever Position Switch (MLPS) which is mounted on the shift shaft on the left side of the transmission. The early ones from your vintage were not sealed very well and the water screwed them up. I think the black ones were the early ones and they then changed to brown later with an orange gasket which was the improved version. It is a different PN.

Birken

05-19-2007, 04:46 AM	#1
harb57 Junior Member Join Date: May 2007 Posts: 1 Points: 179 Thanks: 0 Thanked 0 Times in 0 Posts	GMC C6500 automatic trans "range inhibit" light I have a 2001 gmc c6500 with an allison automatic trans. I have had a few things happen that I'm not sure of and hope someone here knows about. The first and I think this is minor, was last week after the truck had sat about a month( started reguarly but not moved) I put it into drive and nothing happened---so I shifted into reverse then to drive and everything was ok. Today after unloading the truck I got in, shifted from neutral to drive and nothing, but this time I got a "range Inhibit" light. After shifting to reverse and back to drive light went out and transmission went into gear. What does the range inhibit light mean. Other than that the trans shifts fine when driving. This is the first truck I've had with an auto trans. Thanks

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

New To Site?	Need Help?	TDG Specials
Register to Participate TDG Rules View Forum Leaders Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read	TDG Projects TDG Truck of the month

05-19-2007, 01:24 PM	#2
Birken Vogt Fire App. Mech. Join Date: Aug 2005 Posts: 950 Points: 21,509 Thanks: 0 Thanked 40 Times in 34 Posts	If it is an Allison 1000, 2000 or 2400 series it could be related to the Manual Lever Position Switch (MLPS) which is mounted on the shift shaft on the left side of the transmission. The early ones from your vintage were not sealed very well and the water screwed them up. I think the black ones were the early ones and they then changed to brown later with an orange gasket which was the improved version. It is a different PN. Birken

Remove Advertisements Sponsored Links
Diesel Trucks Advertisement