Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P0511: Idle Air Control (IAC) Valve Circuit Failure (2004 3.5RL)
2004 Acura 3.5RLSECTION DTC P0511: Idle Air Control (IAC) Valve Circuit Failure (2004 3.5RL)
- Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Start engine. If DTC P0511 resets, go to next step. If DTC P0511 does not reset, problem is intermittent. System is okay at this time. Check for poor connections or loose wires at connector C253 (located at right shock tower), IAC valve and PCM.
- Turn ignition switch off. Disconnect IAC valve 2-pin connector. Turn ignition switch ON (II). Measure voltage between body ground and IAC valve 2-pin connector terminal No. 2 (Yellow/Black wire). If battery voltage is present, go to next step. If battery voltage is not present, repair open in Yellow/Black wire between IAC valve 2-pin connector terminal No. 2 and PGM-FI main relay.
- Turn ignition switch off. Reconnect IAC valve 2-pin connector. Disconnect PCM 26-pin connector A. See Figure . Turn ignition switch ON (II). Measure voltage between body ground and PCM 26-pin connector A terminal No. 5 (Black/Blue wire). If battery voltage is present, go to next step. If battery voltage is not present, repair open or short in Black/Blue wire between PCM 26-pin connector A terminal No. 5 and IAC valve.
- Turn ignition switch ON (II). Using a fused jumper wire, momentarily connect PCM 26-pin connector A terminals No. 5 (Black/Blue wire) and No. 12 (Black wire) several times. If IAC valve clicks, substitute a known-good PCM, and recheck. If symptom or indication goes away, replace original PCM. If IAC valve does not click, replace 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.