LEMON Manuals: Even more car manuals for everyone
Home >> Honda >> 2017 >> Pilot EX, FWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System - DTC Diagnostics (1 Of 6) >> DTC Troubleshooting >> DTC P0141, P0161 (19-21 9-Speed A/T)

DTC P0141, P0161 (19-21 9-Speed A/T)

DTC P0141  : Rear Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 1, Sensor 2)) Heater Circuit Malfunction

DTC P0161  : Front Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 2, Sensor 2)) Heater Circuit Malfunction

NOTE: 

DTC Description Confirmed DTC Pending DTC
P0141 Rear Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 1, Sensor 2)) Heater Circuit Malfunction    
P0161 Front Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 2, Sensor 2)) Heater Circuit Malfunction    

DTC (PGM-FI)

  1. Problem verification

    -1. Turn the vehicle to the ON mode.

    - 2. Clear the DTC with the HDS.

    - 3. Turn the vehicle to the OFF (LOCK) mode.

    - 4. Start the engine, and let it idle.

    - 5. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC
    P0141 Rear Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 1, Sensor 2)) Heater Circuit Malfunction    
    P0161 Front Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 2, Sensor 2)) Heater Circuit Malfunction    

    Is DTC P0141 and/or P0161 * indicated?

    YES 

    The failure is duplicated. Go to step 2.

    NO 

    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 on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot - Refer to: How to Troubleshoot the Fuel and Emissions Systems .

  2. Secondary HO2S (Sensor 2) internal heater resistance check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Disconnect the following connector.

    Secondary HO2S (Sensor 2) 4P connector

    - 3. At Secondary HO2S (Sensor 2) side, measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Secondary HO2S (Sensor 2) 4P connector: disconnected
    Test point 1
     
    Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (male terminals) No. 3 (sensor side):
    Front secondary HO2S (Bank 2, Sensor 2) 4P connector (female terminals) No. 3 (sensor side) *:
    Test point 2
     
    Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (male terminals) No. 4 (sensor side):
    Front secondary HO2S (Bank 2, Sensor 2) 4P connector (female terminals) No. 4 (sensor side) *:
    GHH307221Courtesy of HONDA, U.S.A., INC.
    GHH307222Courtesy of HONDA, U.S.A., INC.

    Is there 4.2-6.6 Ω at room temperature?

    YES 

    Go to step 3.

    NO 

    Replace secondary HO2S (Sensor 2) .

  3. Secondary HO2S (Sensor 2) internal circuit check

    -1. At Secondary HO2S (Sensor 2) side, check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Secondary HO2S (Sensor 2) 4P connector: disconnected
    Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (male terminals) No. 3 and No. 4 (sensor side):
    Front secondary HO2S (Bank 2, Sensor 2) 4P connector (female terminals) No. 3 and No. 4 (sensor side) *:
    Test point 2 Body ground
    GHH307223Courtesy of HONDA, U.S.A., INC.
    GHH307224Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Replace secondary HO2S (Sensor 2) .

    NO 

    Go to step 4.

  4. Shorted wire check (SO2HT B1 (SO2HT B2) * line):

    - 1.Jump the SCS line with the HDS, and wait more than 1 minute.

    - 2. Disconnect the following connector.

    PCM connector E (80P)

    - 3. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
     
     
    Secondary HO2S (Sensor 2) 4P connector: disconnected
    PCM connector E (80P): disconnected
    Test point 1
     
    PCM connector E (80P) No. 11 - Refer to:
    PCM Connector for Inputs and Outputs (9-Speed A/T) (2019 2020 2021), .
    PCM connector E (80P) No. 24 * - Refer to:
    PCM Connector for Inputs and Outputs (9-Speed A/T) (2019 2020 2021) .
    Test point 2 Body ground

    Is there continuity?

    YES 

    Repair a short in the SO2HT B1 (SO2HT B2) * wire between the PCM (E11 (E24) *) and secondary HO2S (Sensor 2).

    NO 

    The SO2HT B1 (SO2HT B2) * wire is not shorted. Go to step 5.

  5. Open wire check (SO2HT B1 (SO2HT B2) * line):

    - 1.Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
     
     
    Secondary HO2S (Sensor 2) 4P connector: disconnected
    PCM connector E (80P): disconnected
    Test point 1
     
    Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (female terminals) No. 4:
    Front secondary HO2S (Bank 2, Sensor 2) 4P connector (male terminals) No. 3*:
    Test point 2
     
    PCM connector E (80P) No. 11 - Refer to:
    PCM Connector for Inputs and Outputs (9-Speed A/T) (2019 2020 2021),
    PCM connector E (80P) No. 24 * - Refer to:
    PCM Connector for Inputs and Outputs (9-Speed A/T) (2019 2020 2021),
     
    GHH307225Courtesy of HONDA, U.S.A., INC.
    GHH307226Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The SO2HT B1 (SO2HT B2) * wire is OK. Go to step 6.

    NO 

    Repair an open in the SO2HT B1 (SO2HT B2) * wire between the PCM (E11 (E24) *) and secondary HO2S (Sensor 2).

  6. Shorted wire check (IG (LAF O2)/FI SUB line)

    -1. Disconnect the following connectors.

    Relay circuit board connector A (10P)

    - 2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    Relay circuit board: disconnected
    Secondary HO2S (Sensor 2) 4P connector: disconnected
    Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (female terminals) No. 3:
    Front secondary HO2S (Bank 2, Sensor 2) 4P connector (male terminals) No. 4*:
    Test point 2 Body ground
    GHH307227Courtesy of HONDA, U.S.A., INC.
    GHH307228Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the IG (LAF O2)/FI SUB wire between the relay circuit board, secondary HO2S (Sensor 2). Also replace the No. A22 - Refer to: Fuse to Components Index (Without Auto Idle Stop System) (2019 2020 2021) or Fuse to Components Index (With Auto Idle Stop System) (2019 2020 2021)

    NO 

    The IG (LAF O2)/FI SUB wire is not shorted. Go to step 7.

  7. Open wire check (IG (LAF O2)/FI SUB line)

    -1. Check for continuity between test points 1 and 2.

    Test condition
     
     
     
    Vehicle OFF (LOCK) mode
    Relay circuit board: disconnected
    Secondary HO2S (Sensor 2) 4P connector: disconnected
    PCM connector E (80P): disconnected
    Test point 1 Relay circuit board connector A (10P) No. 4
    Test point 2 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (female terminals) No. 3:
    Front secondary HO2S (Bank 2, Sensor 2) 4P connector (male terminals) No. 4*:
    GHH307229Courtesy of HONDA, U.S.A., INC.
    GHH307230Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The IG (LAF O2)/FI SUB is OK. Go to step 8.

    NO 

    Repair an open in the IG (LAF O2)/FI SUB wire between secondary HO2S (Sensor 2) and the relay circuit board.

  8. Open wire check (LAF RLY line)

    -1. Disconnect the following connector.

    PCM connector A (50P)

    - 2. Check for continuity between test points 1 and 2.

    Test condition
     
     
     
     
    Vehicle OFF (LOCK) mode
    Relay circuit board: disconnected
    Secondary HO2S (Sensor 2) 4P connector: disconnected
    PCM connector E (80P): disconnected
    PCM connector A (50P): disconnected
    Test point 1 Relay circuit board connector A (10P) No. 6
    Test point 2 PCM connector A (50P) No. 49 - Refer to:
    PCM Connector for Inputs and Outputs (9-Speed A/T) (2019 2020 2021) .

    Is there continuity?

    YES 

    The LAF RLY wire is OK. Go to step 9.

    NO 

    Repair an open in the LAF RLY wire between the PCM (A49) and the relay circuit board.

  9. Fuse check

    -1. Check the following fuse.

    Fuse No. A22 - Refer to:
    Fuse to Components Index (Without Auto Idle Stop System) (2019 2020 2021) or
    Fuse to Components Index (With Auto Idle Stop System) (2019 2020 2021)

    Is the fuse OK?

    YES 

    Go to step 10.

    NO 

    Repair a short in the +B FI SUB wire between the No. A22 fuse and the relay circuit board. Also replace the No. A22 fuse.

  10. Relay circuit board check

    -1. Remove and test the relay circuit board.

    Is the relay circuit board OK?

    YES 

    The Relay circuit board is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM - Refer to: PCM Removal and Installation (9-Speed A/T 2019 2020 2021), , then recheck. If DTC P0141 and/or P0161* goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (9-Speed A/T 2019 2020 2021) .

    NO 

    Replace the relay circuit board .