P0159 - O2 Circuit Slow Response (Bank 2, Sensor 2)

4-34 Powertrain DTC Charts and Descriptions

Diagnostic Trouble Code (DTC) Charts and Descriptions

P0159 - O2 Circuit Slow Response (Bank 2, Sensor 2) (Continued)

• Damaged HO2S22

Diagnostic Aids: Access the HO2S test results from the Generic OBD II menu to verify the DTC.

Application Key On Engine Off Key On Engine Running Continuous Memory

All GO to Pinpoint Test DW.

P0161 - O2 Heater Circuit (Bank 2, Sensor 2)

Description: This DTC sets when an open or short circuit is detected or the universal heated oxygen sensor bank 2, sensor 2

(HO2S22) heater current draw exceeds a calibrated limit.

Possible Causes: • HTR22 circuit open

• HTR22 circuit short to voltage

• VPWR circuit open

• GND circuit open

• Low battery voltage

• Water in the harness connector

• Corrosion

• Incorrect connections

• Damaged HO2S22 heater

Diagnostic Aids: Inspect the connectors for signs of damage, water intrusion or corrosion.

Application Key On Engine Off Key On Engine Running Continuous Memory

All GO to Pinpoint Test DW.

P0171 - System Too Lean (Bank 1)

Description: The adaptive fuel strategy continuously monitors the fuel delivery hardware. This DTC sets when the adaptive

fuel tables reach a rich calibrated limit. Refer to Section 1, Powertrain Control Software, Fuel Trim for additional information.

Possible Causes: • Ethanol content in the fuel

• Fuel filter plugged or dirty

• Damaged or worn fuel pump

• Leaking fuel pump check valve

• Leaking or contaminated fuel injectors

• Low fuel pressure or running out of fuel

• EVAP purge valve is leaking when the canister is clean

• Fuel supply line restricted

• Fuel rail pressure (FRP) sensor bias

• Exhaust leaks in the exhaust manifold gasket or mating gaskets before or near the heated oxygen sensor

(HO2S)

• Air leaks after the mass airflow (MAF) sensor (if equipped)

• Vacuum leaks

• Positive crankcase ventilation (PCV) system is leaking or the valve is stuck open

• Incorrectly seated engine oil dipstick

• Intake air turbulence due to incorrect air filter

• Contaminated MAF sensor (if equipped)

• Damaged MAF sensor (if equipped)

Diagnostic Aids: View the freeze frame data to determine the operating conditions when the DTC was set. Observe the

LONGFT1 and LONGFT2 PIDs. Refer to Section 2, Adaptive Fuel Diagnostic Trouble Code (DTC) Diagnostic Techniques, for additional information and the appropriate pinpoint test for specific concern identification.

Application Key On Engine Off Key On Engine Running Continuous Memory

All GO to Pinpoint Test H.

P0172 - System Too Rich (Bank 1)

Description: The adaptive fuel strategy continuously monitors the fuel delivery hardware. This DTC sets when the adaptive

fuel tables reach a lean calibrated limit. Refer to Section 1, Powertrain Control Software, Fuel Trim for additional information.

Possible Causes: • Leaking fuel injectors

• Fuel return line restricted

• Fuel rail pressure (FRP) sensor bias

2016 Powertrain Control/Emissions Diagnosis, Gasoline Engines, 3/2015