Applications: 2003-’05 Rio 1.6
Customer Concern: The check engine light is on and there is a mass air flow (MAF) sensor range/performance code in the system. The engine will hesitate at times.
Tech Tips: The P0101 code is more of a rationality check. The MAF sensor signal isn’t rationally making sense comparing to things like throttle position and engine rpm.
Tests/Procedures:
1. Check freeze-frame data for engine parameters when the code sets, and get the throttle position sensor (TPS) voltage, MAF sensor voltage and engine rpm, etc. to help find a potential cause for the problem. Verify the re-flash for code P0101 has been performed; read Kia TSB under engine volume 3, #20 for a re-flash for this code.
2. Verify that there are no air leaks — even a loose oil fill cap or a pulled out dipstick can set this code.
3. Check the MAF sensor for battery voltage on the red/green wire, ground on the yellow wire and output voltage on the green/yellow wire. Look for about 0.6 to 0.8 volts at warm idle.
4. Check the TPS signal voltage on the white wire — specification is 0.2 to 0.8 volts closed throttle and then a nice, smooth voltage increase as the throttle is opened.
Courtesy of Identifix.