DTC P0139: Secondary HO2S (Sensor 2) Slow Response

NOTE: 

• Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions SystemsHow to Troubleshoot the CVT System(CVT System) .
• If there are leaks from the exhaust system, this DTC will be set. Check for damage in the exhaust pipe and repair it if needed.

DTC (PGM-FI)

• 1. Problem verification:

  - 1. Turn the vehicle to the ON mode.

  - 2. Clear the DTC with the HDS.

  - 3. Start the engine.

  - 4. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

  - 5. Test-drive under these conditions:

  • Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C)
  • Transmission in D
  • Drive at a steady speed between 55-75 mph (90-120 km/h) for 1 minute, then decelerate (with the throttle fully closed) for 10 seconds

  Signal	Current conditions
  	Values	Unit
  ECT SENSOR 1
  VEHICLE SPEED

  - 6. Monitor the OBD STATUS for DTC P0139 in the DTCs MENU with the HDS.

  DTC Description	OBD STATUS
  P0139 Secondary HO2S (Sensor 2) Slow Response

  Does the HDS indicate FAILED?

  YES 

  The failure is duplicated. Replace secondary HO2S (Sensor 2) .

  NO 

  If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-4 on this step and recheck.