P2771 GMC - Four Wheel Drive Low Switch Circuit

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3   
Comments  |  Add Comment

P2771 GMC Possible Causes

  • Faulty Four Wheel Drive Low Switch
  • Four Wheel Drive Low Switch harness is open or shorted
  • Four Wheel Drive Low Switch circuit poor electrical connection

First diagnose P2771 GMC code

    Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded terminals.

Cost of diagnosing the P2771 GMC code

    Labor: 1.0

    The cost of diagnosing the P2771 GMC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

P2771 GMC Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P2771 Gmc Description

For vehicles equipped with an active transfer case, the four wheel drive (4WD) low circuit consists of the Powertrain Control Module (PCM) , a transfer case control module and the circuit wiring. The transfer case control module controls the 4WD low signal on the low signal circuit. When the operator selects 4WD low, the transfer case control module grounds the signal circuit, and the 4WD low signal voltage on the circuit changes from ignition voltage to zero volts. The PCM then compensates for transfer case gear reduction in the transmission output shaft speed (OSS) sensor signal. The PCM uses the transmission OSS sensor signal to adjust shift points, line pressure and torque converter clutch (TCC) scheduling.

For vehicles not equipped with an active transfer case, the 4WD low circuit consists of the PCM, a transfer case switch and the circuit wiring. The transfer case switch controls the 4WD low signal on the signal circuit. When the operator selects 4WD low, the transfer case switch closes and the 4WD low signal voltage on the signal circuit changes from ignition voltage to zero volts. The PCM then compensates for transfer case gear reduction in the transmission output shaft speed (OSS) sensor signal. The PCM uses the transmission OSS sensor signal to adjust shift points, line pressure and TCC scheduling.

OBDII Code P2771 Gmc - Four Wheel Drive Low Switch Circuit - AutoCodes.com

P2771 GMC More Information

Need more information on how to fix the P2771 GMC code?
Get Access to Factory Service Manuals

Need more help?

Get the P2771 Gmc code diagnosed by a professional: Find a repair shop in your area

Related Information

P2771 GMC Comments

Help us improve AutoCodes.com. Leave a comment below or tell us if the information above help you fix the code. What are the symptoms on your vehicle for the P2771 Gmc code? Have you replaced any parts?
Any information is appreciated. Thanks
Top ⇧