I own a 1989 Honda Accord LXI 2.0 manual transmission w/ 160,000 miles
New wires, plug and oil change 3/20/2007.

Just recently my check engine light came on while I was driving on a highway at a sustained speed of 75 mph. I pulled over immediately and noticed the car was idling very low (around 500-600rpm).

The ECU for this car is located under the drivers seat and can be accessed from the behind the seat. I had to move the seat all the way forward and pry off a small plastic tab to see the LED which displayed the codes stored on the ECU.

The code I was getting was 14 which translates to a faulty IAC circuit. I visited the DIY section of this forum and read the .pdf forum on diagnosing idle issues for Honda's (90-93). The IAC for an '89 is different than a '90-93 and I don't think the '89 has a fast IAC valve either(at least I didn't see one). I pulled the IAC valve apart and cleaned it, but this didn't solve the problem. I didn't check the function of the solenoid yet, I will jumper the IAC terminals to the battery.

Any additional input as to how I should tackle this situation would be greatly appreciated.

Thanks for your reply.

 

Code 14 is a "faulty IACV circuit". This means the ECU detected a short or open in the circuit. It could be the IACV itself, faulty connector, or damaged wiring. Function check of IACV solenoid is the place to start as this is highest probability of failure.

good luck

 

Thanks guys for the help. I'll update after I do some more tests.