Circuit/System Verification
IMPORTANT:
Disregard any transmission symptoms, antilock brake system (ABS) indicators, and traction control system (TCS) indicators until any fuel trim faults are repaired. A fuel trim fault may cause default actions such as harsh shifts and illumination of the ABS/TCS indicators
- If any DTCs other than DTC P0174 or P0175 are also set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Allow the engine to reach operating temperature. With the engine running, observe the HO2S parameter with a scan tool. The HO2S 1 value should vary from approximately 40 mV to approximately 900 mV, and respond to fueling changes.
- If the value does not vary from approximately 40 mV to approximately 900 mV, refer to DTC P0151, P0152, or P0154 , DTC DTC P0153, P1153, or P2A03 , DTC DTC P0050, P0059, or P0155 , DTC DTC P0157, P0158, or P0160 , DTC P2A04 , or DTC DTC P0056, P0060, or P0161 .
- The normal Short Term FT parameter should be moving rapidly between +10 percent and -10 percent, with near 0 percent the optimum, with the engine running at operating temperature.
- The Long Term FT parameter should be moving slowly between +10 percent and -10 percent, with near 0 percent the optimum, with the engine running at operating temperature.