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 (4 Of 6) >> DTC Troubleshooting >> DTC P1659 (19-21 9-Speed A/T)

DTC P1659 (19-21 9-Speed A/T)

DTC P1659  : Electronic Throttle Control System (ETCS) Control Relay OFF Malfunction

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems .

DTC Description Confirmed DTC Pending DTC
P1659 Electronic Throttle Control System (ETCS) Control Relay OFF 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. Turn the vehicle to the ON mode.

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

    DTC Description Confirmed DTC Pending DTC
    P1659 Electronic Throttle Control System (ETCS) Control Relay OFF Malfunction    

    Is DTC P1659 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 the relay circuit board (ETCS control relay circuit) 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. Fuse check

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

    - 2. Check the following fuse.

    Fuse No. A24 - Refer to:
    Fuse to Components Index (With Auto Idle Stop System) (2019 2020 2021), or
    Fuse to Components Index (Without Auto Idle Stop System) (2019 2020 2021), or

    Is the fuse OK?

    YES 

    Go to step 3.

    NO 

    Go to step 7.

  3. 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. Go to step 4.

    NO 

    Replace the relay circuit board .

  4. Open wire check (+B DBW line)

    - 1. Reinstall the relay circuit board without reconnecting relay circuit board connector B (16P).

    - 2. Measure the voltage between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    Relay circuit board connector B (16P): disconnected
    Test point 1 Relay circuit board connector B (16P) No. 2
    Test point 2 Body ground

    Is there battery voltage?

    YES 

    The +B DBW wire is OK. Go to step 5.

    NO 

    Repair an open in the +B DBW wire between the No. A24 fuse and the relay circuit board. - 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)

    If the wire is OK, replace the under-hood fuse/relay box .

  5. Open wire check (IG1 (DBW) line)

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

    - 2. Disconnect the following connector.

    PCM connector A (50P)

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

    Test condition Vehicle OFF (LOCK) mode
    Relay circuit board connector B (16P): disconnected
    PCM connector A (50P): disconnected
    Test point 1 Relay circuit board connector B (16P) No. 3
    Test point 2 PCM connector A (50P) No. 2 - Refer to:
    PCM Connector for Inputs and Outputs (9-Speed A/T) (2019 2020 2021)

    Is there continuity?

    YES 

    The IG1 (DBW) wire is OK. Go to step 6.

    NO 

    Repair an open in the IG1 (DBW) wire between the PCM (A2) and the relay circuit board.

  6. Open wire check (DBW RLY line)

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

    Test condition Vehicle OFF (LOCK) mode
    Relay circuit board connector B (16P): disconnected
    PCM connector A (50P): disconnected
    Test point 1 Relay circuit board connector B (16P) No. 1
    Test point 2 PCM connector A (50P) No. 41 - Refer to:
    PCM Connector for Inputs and Outputs (9-Speed A/T) (2019 2020 2021)

    Is there continuity?

    YES 

    The DBW RLY wire 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 (19-21 9-Speed A/T), , then recheck.

    If DTC P1659 goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (19-21 9-Speed A/T) .

    NO 

    Repair an open in the DBW RLY wire between the PCM (A41) and the relay circuit board.

  7. Shorted wire check (IG1 (DBW) line)

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

    - 2. Disconnect the following connectors.

    PCM connector A (50P)
    Relay circuit board connector B (16P)

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

    Test condition Vehicle OFF (LOCK) mode
    Relay circuit board connector B (16P): disconnected
    PCM connector A (50P): disconnected
    Test point 1 PCM connector A (50P) No. 2 - 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 IG1 (DBW) wire between the PCM (A2) and the relay circuit board. Also replace the No. A24 fuse. - 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 IG1 (DBW) wire is OK. Go to step 8.

  8. Shorted wire check (+B DBW line)

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

    Test condition Vehicle OFF (LOCK) mode
    Relay circuit board connector B (16P): disconnected
    PCM connector A (50P): disconnected
    Test point 1 Relay circuit board connector B (16P) No. 2
    Test point 2 Body ground

    Is there continuity?

    YES 

    Repair a short in the +B DBW wire between the No. A24 fuse and the relay circuit board. - 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)

    If the wire is OK, replace the under-hood fuse/relay box . Also replace the No. A24 fuse.

    NO 

    The +B DBW wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. - Refer to: PCM Removal and Installation (19-21 9-Speed A/T) .

    If DTC P1659 goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (19-21 9-Speed A/T) . Also replace the No. A24 fuse.