Mazda Tech Tip: Rough Idle After Idle Air Control Valve Replacement – UnderhoodService

Mazda Tech Tip: Rough Idle After Idle Air Control Valve Replacement

A car might be over 20 years old, but that doesn't mean the customer isn't concerned with how it runs. In this case, the component related to the code was not the culprit.

A car might be over 20 years old, but that doesn’t mean the customer isn’t concerned with how it runs. In this case, the component related to the code was not the culprit.

Vehicle

1995 Mazda B2300 2.3L

Complaint

The customer states the engine idles rough. The customer also states the check engine light is on.

Cause

Confirmed the customer’s complaint and found the engine idled rough. Connected a scan tool and found code P1443 – Purge Flow System Circuit Malfunction. At idle, used the scan tool to monitor live data and found the evaporative emission (EVAP) purge flow sensor signal parameter was within the specified range of 1.5 to 2.0 volts. At idle, used the scan tool to command the purge solenoid open and observed the EVAP purge flow sensor signal parameter responded to changes in commanded purge rate and engine speed. Observed the idle speed was below the specified 475 to 575 rpm. Used the scan tool to command the idle air control valve on and found engine RPM did not change, indicating the idle air control valve was inoperative. Inspected the idle air control valve wiring harness and found no faults. Connected a test light in place of the IAC valve, used the scan tool to command the IAC valve on and found the test light was illuminated, indicating the wiring and control circuit were functional. Used a set of fused jumper wires and applied power and ground to the idle air control valve and found the idle air control valve failed to operate. Used a multimeter to measure the resistance of the idle air control valve and found the measured resistance was out of the specified range of 6 to 13 Ohms. The results of these tests indicated the idle air control valve was faulty.

Correction

Replaced the idle air control valve, cleared codes, performed a road test and verified the vehicle operated properly. The check engine light did not illuminate and no fault codes returned.

Courtesy of Mitchell 1 SureTrack Real Fix

You May Also Like

Autel MaxiSYS Ultra Enhances Efficiency At Mighty Auto Pro

Time is money in vehicle repair, and the Autel MaxiSYS Ultra is all about enhancing technicians’ diagnostic prowess.

At Mighty Auto Pro, an auto repair shop in Medina, Ohio, a range of quality services and a staff with a great customer demeanor are behind this shop’s rabid fanbase, but tools like the Autel MaxiSYS Ultra prove to be a real ace up their sleeve. Time is money in vehicle repair, and the Autel MaxiSYS Ultra is all about enhancing technicians’ diagnostic and service efficiency.

Financial Foresight For A Smooth Succession

An effective succession plan provides a smooth transition in management and ownership with a minimum of financial hassle.

Mullen Announces Class 1 EV Sale Through Eco Auto

Mullen announced its partnership with Eco Auto, a national franchise of automotive dealerships, earlier this month.

Inspection Tips For Chain-Driven Water Pumps

If one water pump fails sooner and is replaced without an investigation, the new pump is likely doomed.

Water pump feature
Honda Electronic Throttle Body Service Tips

Using care and following OEM procedures will help you to avoid unnecessary parts replacement and comebacks.

Other Posts
Plastic Timing Chain Guides

Timing chain guides are designed to wear, but the guides are designed to last the engine’s life.

Polestar Vehicles to Use TactoTek Smart Surface Technology

The technology allows lighting features and human machine interfaces that are more sustainable, the companies say.

Diesel Particulate Filter Regeneration

The DPF has thousands of tiny channels that trap the soot and prevent the particulate matter from exiting out the tailpipe.

Road to AAPEX Ep. 1: The Future of the Automotive Aftermarket

Travel a new Road to AAPEX this season by watching the first episode in this year’s Road to AAPEX series.