Engine light on showing p005,replaced iacv but light stayed on,what else can i do.

P0505 - Idle Control System Malfunctionhttp://engine-codes.com/p0505.htmlForum CodePossible causes- IACV-AAC valve harness is open or shorted
- IACV-AAC valve poor electrical connection
- Faulty IACV-AAC valve

Read more: http://engine-codes.com/p0505.html#ixzz1zVJIt34L

Hello and welcome to FixYa!
This can be caused by a faulty IACV (idle air control valve). If the IACV is faulty the engine can misfire or can cause stalling. The IACV is located on the throttle body. You may need to just clean it for the strainer can be full of dirt. If cleaning doesn't resolve it then you may need to have it replaced.
Hope this helps and thank you for using FixYa! Have a good one!

Hi and welcome to FixYa!

This problem is common on all honda cars. As a first course of action, I strongly suggest that you clean the IACV (idle air control valve) by using a carburetor cleaner. The IACV has strainer and mostly clogged by dirt. If it's blocked the engine may stall and may have irregularities on acceleration.

The IACV is located on the throttle body secured by two bolts. You will need to remove the connector first before removal.

Hope this helps and thank you for using FixYa! Have a good one!

Hi, please have the car scanned at your local parts chain and send us the trouble codes. If I had to guess, I would say MAP sensor, but it will be much easier to help you with the trouble codes in hand.

Please see my tip at http://www.fixya.com/cars/r5932051-check_engine_light_check. These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

Make sure the throttle body interior and throttle plate are clean and then check both the 1) idle air control valve and the 2) throttle position sensor:
1) Idle air control valve - How to check? Physically remove the IACV, keep the electrical connection to it and blank off the port to the intake plenum. Turn the engine on (you will need a little accelerator pedal pressure to keep her running) and examine the IACV valve movement in response to additional loads (power steering inputs etc). The valve should open and close according to demand which when fitted would cause change in engine speed with increased power demand made on the engine.

The electrical connector to the IACV can have 2 or 4 pins:-

2 pins: resistance between pins should about 10 OHMS +/- 3 OHMS. Resistance between either of the pins and the valve body is greater than 10,000 OHMS

4 pins: resistance between diagonally positioned pins should be about 20 OHMS

How to fix? If the motor of the IACV has failed then replace it. If the valve is gummed closed by baked oil and carbon then clean it thoroughly with carburetor choke cleaner spray and a cloth. Similarly if the entry and exit ports on the throttle body to the IACV look blocked again clean them out thoroughly.

2) Throttle position sensor - How to check? The socket for electrical connection with the TPS has 3 pins, one for 'ground', one for 5 volts 'reference' and a third (generally the middle one) for 'signal' output. Back probe the signal pin in the connector to the TPS. Attach the positive lead of a voltmeter to the probe and measure the voltage output as the throttle plate is rotated. If working correctly the meter should show a voltage consistent with the throttle position from approximately 1 volt when closed and 5 volts when fully open. What is looked for is smooth voltage increase with throttle change. If there are drop outs in the transition or that there is no transition seen the TPS is faulty.

How to fix? If the track is dirty causing drop outs, try cleaning it with residue-free electrical cleaning spray. If the track is worn it is perhaps easiest to replace the complete device. In some instances it may be possible to adjust the location of the central mount of the TPS contact arm along the throttle shaft by a few millimeters and in the process cause a fresh concentric region of track to be used.

You probably have a bad Idle Air Control Valve (IACV). In fuel injected carburetors when the throttle valve is closed the IACV opens and closes to control the idle speed. If it malfunctions the engine may rev up allowing the car if in gear to accelerate on its own . When I had a bad IACV in my Mitsubishi Lancer it would drive down the road at 50 mph with out touching the gas pedal. Fortunately, it could be slowed down by using the brakes (unlike the Toyota stories).

Hello! The most likely culprit is the Idle Air Control Valve (IACV)...Has a 4 wire connector...Colors are...Light Blue/White...Light Blue/Black...Light Green/Black...And Light Green/White...Check connector for dirty contacts, loose or broken wires...It is more than likely fouled with carbon...Remove and clean port and tip...If cleaning does not cure the fault IACV needs to be replaced...Guru..........saailer



I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Hey Jruthesq

The 850 is equipped with an Idle Air Control Valve (IACV) which supplies the engine with air when idleing (a necessity since the main throttle body valve is completely closed when no throttle is applied, thus the engine would lack air without the IACV when idleing). The IACV is suspended in a rubber mount on the front of the throttle body itself, and is easily removed and inspected/cleaned. If it's dead a good cleaning usually gets it going again. Also make sure that the air from the IACV is unhindered on its way from the IACV to the throttle body (it's actually common for the holes in the throttle body to be gunked up so bad by hardened carbon deposits that one sometimes needs a nail or even a drill to open it up again).

Just thought I'd mention this since you said that the gas needs to be feathered for the engine to start. When you press down on the gas the main valve in the throttle body opens up, closing the IACV and supplying the engine with enough air.

Oh and if your fuel pump relay is a green one marked 103 you should replace it with the new and improved red one. The relay is located under the fuse box cover under the hood. Remove the 4 torx srews holding the cover in place and you'll see the relays under there.

Good luck mate!

possible the EGR valve may be struck open, recommending take egr off and free up the pintal with wire brush, may have carbon build up. Is your engine light on? If so it could be your IACV.