Diagnostic Procedure

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Suburban, and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: DTC P0135, P0141, P0155 & P0161: HO2S Heater Circuit - Bank 1 & 2, Sensors 1 (Steps 1-10)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC P0135, P0141, P0155 & P0161: HO2S Heater Circuit - Bank 1 & 2, Sensors 1 (Steps 11-23)

Courtesy of GENERAL MOTORS CORP.