1999 GMC Sierra 2500 Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 1999 GMC Sierra 2500
Verified by mechanics, reported by drivers like you
Ask a mechanic in our community
Never overpay. Check prices with our estimator
1999 GMC Sierra 2500 ProblemsCheck Engine Light With Code P1870
Vehicles equipped whit a 4 speed automatic transmission may develop a harsh 1-2 shift and/or illumination of the Check Engine Light with code P1870 stored. This can be caused by wear of the bore for the TCC isolator and regulator valves in the valve body. This condition does not commonly occur until the transmission reaches normal operating temperature. If the valve body is worn, replacement will be necessary to correct this concern.
A rattling noise may develop from the AC belt tensioner. This can be caused by an internal fault with the AC compressor, AC performance may also be diminished when this occurs. Our technicians tell us that replacing the ac compressor will commonly correct this concern.
1999 GMC Sierra 2500 Questionswhen i refilled the transfer case I am hearing a whistle noise is that normal? (1 answer)
my transfer case was not going into gears right with my 4x4 gm sierra 2500 1999 model. i refilled it with the transfer oil. but i am hearing a whistle noise, it is shifting now and not jumping like the emergency brake is on..do you know what the whistle noise could be???? I am stuck in the mounta...
how can you check to see if the transfer case for my 4x4 needs fluid
I replaced all the brake lines with Cunifer then bled them at the wheels. The one that goes from the control box (under cab) to rear wheels is leaking. It is screwed in fully and tight but when pressure is applied fluid comes out around the line/fitting. I flared them all the same but none of th...