OBD2 Code P0135 on 2002 GMC Escalade: Location and Diagnosis Guide
I'm experiencing OBD2 diagnostic code P0135 on my 2002 GMC Escalade. Could someone please confirm the exact location of the oxygen sensor (O2) associated with this code? Specifically, I need to know where the B1S1 oxygen sensor is situated in the exhaust system.
B1S1 refers to the heater performance of the front oxygen sensor on the driver's side exhaust. Check the wiring harness and related fuses—ensure there is 12V on the pink wire and a solid ground on the black wire. The sensor heater resistance should read between 3.5 and 14.0 ohms when tested. If replacing, use an original GM sensor only—not aftermarket parts.