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Home >> Honda >> 2019 >> Pilot EX, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System / Engine Mechanical - Service, Testing & Troubleshooting >> Troubleshooting >> A/C Signal Circuit (6-Speed A/T), ('16-'18 9-Speed A/T)

A/C Signal Circuit (6-Speed A/T), ('16-'18 9-Speed A/T)

  1. A/C compressor clutch condition check

    -1. Start the engine, and let it idle.

    - 2. Turn the blower switch on.

    - 3. Turn the A/C switch on.

    - 4. Check the parameter(s) below with the HDS.

    Signal Threshold Current conditions
    Values Unit Values Unit
    A/C CLUTCH ON      

    Do the current condition(s) match the threshold?

    YES 

    Go to step 2.

    NO 

    Do the A/C System Test (1234yf) .

  2. A/C system check

    -1. Check the A/C system. A/C System Test (1234yf) .

    Does the A/C system operate?

    YES 

    The A/C system circuit is OK.

    NO 

    Go to step 3.

  3. A/C compressor clutch circuit check

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

    - 2. Turn the vehicle to the ON mode.

    - 3. Activate the A/C CLUTCH in the INSPECTION MENU with the HDS.

    A/C CLUTCH

    Is there a clicking noise from the A/C compressor clutch?

    YES 

    The A/C compressor clutch circuit is OK. Do the A/C System Test (1234yf) .

    NO 

    Go to step 4.

  4. Open wire check (ACC line)

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

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

    SCS Short

    - 3. Disconnect the following connector.

    PCM connector A (51P)

    - 4. Turn the vehicle to the ON mode.

    - 5. Connect terminals A and B with a jumper wire.

    Terminal A PCM connector A (51P) No. 23 - Refer to:
    PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020)  or
    PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018) .
    Terminal B Body ground

    Is there a clicking noise from the A/C compressor clutch?

    YES 

    The ACC wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM - Go to: PCM (6-Speed A/T), ('16-'18 9-Speed A/T) - Removal and Installation

    .

    NO 

    Check for poor connections or loose terminals at the A/C compressor clutch relay and the PCM. If the connections and terminals are OK, check the No. C23 (7.5 A) fuse in the under-dash fuse/relay box. If the fuse is OK, check the A/C compressor clutch relay. If needed, repair an open in the ACC wire between the PCM (A23) and the A/C compressor clutch relay, or other parts in the A/C systems.