DTC P1519: IAC Valve Circuit Malfunction

2004 Acura 1.7EL StandardSECTION DTC P1519: IAC Valve Circuit Malfunction
  1. Reset the ECM/PCM (see HOW TO RESET THE ECM/PCM ).
  2. Turn the ignition switch ON (II).

    Is DTC P1519 indicated? 

    1. YES  - Go to step 3.
    2. NO  - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the IAC valve and at the ECM/PCM.
  3. Turn the ignition switch OFF.
  4. Disconnect the IAC valve 3P connector.
  5. Turn the ignition switch ON (II).
  6. Measure voltage between the IAC valve 3P connector terminal No. 2 and body ground.
    Fig 1: Measuring Voltage Between IAC Valve 3-Pin Connector Terminal No. 2 & Body Ground
    G01954845

    Is there battery voltage? 

    1. YES  - Go to step 7.
    2. NO  - Repair open in the wire between the IAC valve and the PGM-Fl main relay.
  7. Turn the ignition switch OFF.
  8. Check for continuity between body ground and IAC valve 3P connector terminal No. 1.
    Fig 2: Checking Continuity Between Body Ground & IAC Valve 3-Pin Connector Terminal No. 1
    G01954846

    Is there continuity? 

    1. YES  - Go to step 9.
    2. NO  - Repair open in the wire between the IAC valve and G101.
  9. Disconnect ECM/PCM connector A (31P).
  10. Check for continuity between body ground and ECM/PCM connector terminal A12.
    Fig 3: Checking Continuity Between Body Ground & ECM/PCM Connector Terminal A12
    G01954847

    Is there continuity? 

    1. YES  - Repair short in the wire between the IAC valve and the ECM/PCM (A12).
    2. NO  - Go to step 11.
  11. Connect the IAC valve 3P connector terminal No. 3 and body ground with a jumper wire.
    Fig 4: Connecting IAC Valve 3-Pin Connector Terminal No. 3 & Body Ground
    G01954848
  12. Check for continuity between ECM/PCM connector terminal A12 and body ground.
    Fig 5: Checking Continuity Between ECM/PCM Connector Terminal A12 & Body Ground
    G01954849

    Is there continuity? 

    1. YES  - Go to step 13.
    2. NO  - Repair open in the wire between the IAC valve and the ECM/PCM (A12).
  13. Reconnect the IAC valve 3P connector.
  14. Turn the ignition switch ON (II).
  15. Measure voltage between body ground and ECM/PCM connector terminal A12.
    Fig 6: Measuring Voltage Between Body Ground & ECM/PCM Connector Terminal A12
    G01954850

    Is there battery voltage? 

    1. YES  - Reprogram the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck (see ECM/PCM REPROGRAMMING AND SUBSTITUTION FOR TESTING ). If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
    2. NO  - Replace the IAC valve.
RENDER: 1.0x

NO RELATED

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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.