2002 Honda Civic SiFACTORY OEM SERVICE PROCEDURE

A/C Signal Circuit Troubleshooting

  1. Turn the ignition switch ON (II).
  2. Momentarily connect ECM connector terminals A24 and E18 with a jumper wire several times.
    1. Is there a clicking noise from the A/C compressor clutch? 
      1. YES:  Go to step 3.
      2. NO:  Go to step  6.
      2. Fig 1: Momentarily Connecting ECM Connector Terminals A24 And E18 With A Jumper Wire
      G01399529Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Start the engine.
  4. Turn the blower switch ON.
  5. Turn the A/C switch ON.
    1. Does the A/C operate? 
      1. YES:  The air conditioning signal is OK.
      2. NO:  Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck (see ECM UPDATING AND SUBSTITUTION FOR TESTING ). If the symptom/indication goes away with a known-good ECM, replace the original ECM.
  6. Momentarily connect under-hood fuse/relay box 14P connector terminal No. 10 to body ground with a jumper wire several times.
    1. Is there a clicking noise from the A/C compressor clutch? 
      1. YES:  Repair open in the wire between the ECM (E18) and the A/C clutch relay.
      2. NO:  Check the A/C system for other symptoms.
      2. Fig 2: Momentarily Connecting Under-Hood Fuse/Relay Box 14P Connector Terminal No. 10 To Body Ground With A Jumper Wire
      G01399530Courtesy of AMERICAN HONDA MOTOR CO., INC.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.