Technical Service Bulletin PIT4815C — 2012 GMC YUKON DENALI

This Preliminary Information communication provides information to the technician with additional vehicle speed sensor diagnostic information. Technician may encounter multiple issues when diagnosing a Vehicle Speed Sensor. Technician will find it difficult to follow the speed signal path between the components. To test connect the Fluke meter leads between circuits 821 and 822 and set the meter to Alternating current voltage and then press the hertz button. When the Engine Control Module showing correct miles per hour in the data list however it is setting a Diagnostic Trouble Code for the Vehicle Speed Sensor. To test connect the Fluke meter red lead to circuit 6399 and the black lead to ground, then set the meter to Direct current voltage and press the hertz button. The Instrument Panel Cluster speedo will work correctly when the Engine Control Module or Antilock Braking System Diagnostic Trouble Codes are for the Vehicle Speed Sensor. To test connect the Fluke meter red lead to circuit 1827 and the black lead to ground, then set the meter to Direct current voltage and press the hertz button. When the Antilock Braking System Malfunction Indicator Lamp on with Electronic Brake Control Module Diagnostic Trouble Code C0055 and no other customer complaints, to test connect the Fluke meter red lead to circuit 817 and the black lead to ground, then set the meter to Direct current voltage and press the hertz button.