P1875 GMC Code - 4WD Low Switch Circuit Electrical

Quick Answer

With the engine speed over 450 rpm for 5 seconds, Fuel Cutoff not active, Vehicle Speed Sensor (VSS) input over engine vacuum at 0-105 kPa, gear range is D4, shift solenoid performance counters at zero, Transmission Fluid Temperature (TFT) input from 68-266°F, then Condition 1: 4WD Low switch in 4WD low, transfer case not in 4WD low, Torque Converter Clutch (TCC) slip speed from -3000 to -50 RPM, and VCM detected the speed ratio was 0.8-1.2 (speed ratio is rpm divided by the output speed) Condition 2: 4WD Low switch not in 4WD low, transfer case in 4WD low, TCC commanded on, TCC slip speed was 100 to 3000 RPM, and the VCM detected that the speed ratio was 2.5-2.9 for 10 seconds Common causes include Faulty 4WD Low Switch, 4WD Low Switch harness is open or shorted, 4WD Low Switch circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means

P1875 GMC indicates 4WD Low Switch Circuit Electrical.

Common causes

Common causes include Faulty 4WD Low Switch, 4WD Low Switch harness is open or shorted, 4WD Low Switch circuit poor electrical connection.

Severity

High - diagnose this code as soon as possible.

Can I drive?

Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.