FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

DTC P0138

DTC: P0138 Oxygen sensor 2 (G3/1) circuit high voltage

Activation requirement CHECK ENGINE lamp:
Two consecutive trips with failure.

Activation of CHECK ENGINE lamp:
At start of next trip.

Test to detect fault:
With the oxygen sensor control activated, the diagnostic module checks if approximately 1280 mV is exceeded for longer than approximately 2.5 seconds.