N o revs p1639 p1631 - Cars & Trucks

Could be shorted 5v reference or any number of modules using 5v ref are causing low voltage.

See following video for how to troubleshoot 5v ref circuit.

https://youtu.be/RcQdITo_AOA

code p 0707 refers to transmission range (TR) sensor / switch---low input ==causes --wiring short to ground --TR sensor / switch---ECM --TCM
code p1631 will refer to traction control system
check wiring and harness connections
have an accredited transmission specialist cehec sensor and switch

This means you have a bad transmission control module, engine control module, or dataline...The code specifically means there was a communication problem between the two modules

http://ww2.justanswer.com/uploads/mcvgreg/2007-12-29_025620_2000-Tahoe-P1631-Debug.pdf

P1631
ECM (Voltage Regulator) - Malfunction

Four digit codes are brand specific, for Kia the code means the main circuit for the alternator is open, or it is not charging the battery.

hello sir how r u .. i have a problam on my car.GMC ENVOY . where r showing trobol code p1631.and this car is not working.. plz telll me how to solbe this problam.

Something is taking away , by a short usually, the 5 volt reference signal from the PCM causing your issues .

p1639 is low a/c refrig. so that's not it. p0113 is low intake air temp. which is telling the computer its -38 f. This can cause the idle to be raised. and p0401 is EGR flow test failed.
Can you post what motor this has 3.8 liter or the 3.4 liter. This is something that we need to know.

P0455 IS AUXILIARY EMISSION CONTROL
P1631 IS MANUFACTURE CONTROL AUXILIARY INPUTS AUXILIARY OUTPUTS