The Idle Air Control valve is a complicated mechanism that opens to allow air into your intake manifold without the use of your throttle body. Your Honda Accord ECU controls the engine idle by activating the idle air control valve into action. As the engine and combustion chambers need it, this valve opens to allow unmetered air to enter the engine.
OBDII DTC P0505 is a trouble code that’s very common in the Honda Accord. Today’s test vehicle is a 1999 Honda Accord EX with the 2.4 liter SOHC F23 VTEC engine. Today I’ll be showing you How To Replace Idle Air Control Valve in your Honda Accord. If you have not already done so, try adjusting your idle screw or clearing your OBDII check engine code by using a scan tool.
The specific verbiage for the DTC P0505 is Idle Air Control (IAC) Malfunction. We’ll be replacing the IAC in your SOHC 2.3 liter F23 VTEC engine, and showing you how to do this in a 1999 Honda Accord.
The part number for this Honda Accord IAC is 36460-PAA-L21 and most replacement units come with the three way idle air control valve gasket.
Symptoms of DTC P0505
- Hard to start engine
- Irregular idle
- Bad performance
The Idle Air Control Valve is a stepper motor that uses coolant to quiet it’s operation. Because of this, you will need to check several coolant ports and disconnect them. Part of our how to replace idle air control valve DIY guide is disconnecting these coolant lines, and removing the IAC.
If you are working on the same vehicle we are, you know how tight of a fit this can be. Try to keep your tool selection to open ended, smaller 10mm ratches to help you get this job done.
Before you begin our how to replace the idle air control valve in your Honda Accord DIY Guide, disconnect the negative terminal on your battery. Now open your hood and locate both your manifold absolute pressure sensor (MAP) and your throttle position sensor (TPS) and disconnect both.
There’s two coolant hoses that are clamped onto the bottom two nipples, and one goes to the coolant passages from your throttle body. The other coolant hose leads to the back of your Honda Accord engine and connects to the water pipe.
The last hose leads to the intake tract, and it’s the source of your IAC air. Do not mix up these hoses, or you’ll be flooding your engine with coolant. For best results, leave these hoses on until the last step.
Remove the 10mm bolts that hold your Honda Accord Idle Air Control Valve to the back of your F23 intake manifold.
Remove your idle air control valve, and clean the back of your intake manifold.
If your old idle air control valve gasket is still stuck on the intake manifold, remove and discard. After cleaning your mounting surface, take your new Honda idle air control valve and carefully transfer over the hoses. Do not mix up these hoses and make sure that the vacuum hose is the top most one out of the trio of nipples coming out of your IAC.
Once you have transferred over the hoses and done it one hose at a time, insert the new idle air control gasket. Honda does not call for gasket maker here, carefully mount the new unit with new gasket and tighten the 10mm bolts to complete our guide.
Using a scan tool, erase your OBDII DTC P0505 and go on a test drive to see if this condition returns. Once you’ve replaced the idle air control valve and installed it, you have fixed your DTC P0505 for Idle Air Control Valve Malfunction. Have a question about our DIY guide on How To Replace Idle Air Control Valve? Leave us a message below!