P1875 on GMC
4WD Low Switch Circuit (GM)
P1875 on GMC vehicles indicates 4wd low switch circuit (gm). Au7o has documented this code across 1 GMC model — most commonly on Sierra 1500. P1875 is a GM-specific code indicating a fault in the 4WD low switch circuit, which is monitored by the transmission/transfer case or vehicle control module. This switch tells the control module when four-wheel-drive low range is selected so the system can adjust transmission and transfer-case behavior. The code sets when the module sees a continuous open, short to ground, or short to power in that circuit. You may have trouble engaging or disengaging 4WD low and may see a 4WD or service warning light.
Common Causes of P1875
- •Faulty 4WD low range switch
- •Open or shorted wiring in the 4WD low switch circuit
- •Corroded or loose connector at the switch or transfer case
- •Damaged wiring harness near the transfer case
- •Faulty transfer case control / encoder motor
- •Poor ground or chafed wire
- •Failed transfer case or transmission control module (less common)
P1875 on GMC by Model
GMC Sierra 1500(1 issue)
- Transfer Case Unintended Shift to Neutral2014-2015
An electrical signal short in the transfer case can cause it to shift to neutral without driver input while driving. This results in sudden loss of power to the wheels creating a serious safety hazard, particularly at highway speeds or when towing.
Looking for P1875 on a different make?
View P1875 across all makes →Frequently Asked Questions
What does P1875 mean on GMC?▼
P1875 stands for "4WD Low Switch Circuit (GM)." P1875 is a GM-specific code indicating a fault in the 4WD low switch circuit, which is monitored by the transmission/transfer case or vehicle control module. This switch tells the control module when four-wheel-drive low range is selected so the system can adjust transmission and transfer-case behavior. The code sets when the module sees a continuous open, short to ground, or short to power in that circuit. You may have trouble engaging or disengaging 4WD low and may see a 4WD or service warning light. On GMC specifically, this code is documented across 1 model.
What causes P1875 on GMC vehicles?▼
Common causes on GMC: Faulty 4WD low range switch, Open or shorted wiring in the 4WD low switch circuit, Corroded or loose connector at the switch or transfer case, Damaged wiring harness near the transfer case, Faulty transfer case control / encoder motor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1875 on a GMC?▼
Repair costs vary widely depending on the root cause and specific GMC model.
Which GMC models have P1875 documented?▼
Au7o has documented P1875 on 1 GMC model: Sierra 1500.