I've recently got these two engine codes, "P0838, and P0837. I found out they mean, "P0837 -Four Wheel Drive (4WD) Switch Circuit Range/Performance, P0838 -Four Wheel Drive (4WD) Switch Circuit Low". So, is my transfer case switch/sensor in need of replacing? Ever since I brought it I've gotten the part-time light on, even though it's in 2WD. I firgured the switch is the problem, since research brought it up as a common issue.

PS: I also have P1491, which I'm guessing means I need the radiator replay needs to be replaced, am I correct?

Thank you for your time!

25 views and no reply? Does anybody know?!

Have you checked the 4WD linkage to make sure it's not out of adjustment and causing your sensor to trip the codes ?? If it isn't linage related then your probably right about the sensors needing replacement..Also what year is it ?? this might help get the answers you're looking for.

_________________
'02 Sport 4x4, 3.7L, 245/70R16 Bigfoot A/T tires, Tow Hooks, Rear Hitch

Those codes indicate a fault with the switch itself, not the external linkage. The sensor is a resistive multiplex switch meaning that each position has a corresponding, known resistance value. The selector plate in the transfer case moves the switch to a different position for each 4wd position. The PCM supplies a reference voltage and monitors the return side of the circuit to determine what mode the transfer case is in. There's probably an open circuit in the switch. If you want to check the switch to be sure, these are the resistance values.



Actually those are for an NV231 in a 2006. I dont know what year and case model you have.

_________________
2006 Sport 4X4, Deep Beryl Green, NSG370, NV241J, Lifted with OME 927/948 and Bilstein, JBA 4.5 UCA's, Custom 3" Rear Y-Link Extension and Swaybar Relocation, 265/75-16 Toyo Open Country AT2 tires, Black Plastidipped bumpers, flares, and doors, Pioneer speakers, Alpine head unit, 1200w Phoenix Gold Amp, 12" Dayton Reference sub.

Okay, so I DO need to replace the transfer case switch, correct?