Sephia LS Sedan L4-1.8L (1998)
Air Flow Meter/Sensor: Technical Service Bulletins
Engine Controls - Mass Air Flow Sensor Test
SOURCE: Kia Technician Times
TITLE: Mass Airflow Sensor
APPLIES TO:
98-00 Sephia
98-00 Sportage
SERVICE TIP:
Before replacing a Mass Air Flow Sensor (MAF) on 1998 to 2000 Sephia and Sportage vehicles, take a few minutes to verify the operation. You will
need: voltmeter, test leads and Kia SST # K99V2100G17, otherwise known as BOB (Kia Break Out Box). If BOB is unavailable, you can back-probe
pin #4 of the MAF to verify the voltage readings.
1. Connect BOB using the appropriate harness adapter, to the engine harness and ECU.
2. Turn ignition key to "ON" (engine not running).
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Measure MAF output voltage:
Red (+) lead to BOB pin #41
Black (-) lead to BOB pin #14
a. Voltmeter reading: normal is 0.1 to 0.3 volts.
b. If voltage exceeds 0.5 volts, MAF is defective.
3. Start and warm the engine (test drive).
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Engine warm, measure MAF output voltage
Red (+) lead to BOB pin #41
Black (-) lead to BOB pin #14
a. Voltmeter reading at idle: normal is 0.7 to 1.3 volts and stable.
b. Voltmeter reading should increase as engine speed increases.
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If voltage is less than 0.4 volts, check power supply (from ECU) at the MAF pin #3. Voltage should be system voltage (approximately 12
volts).
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The system ECU output voltage can also be checked at the BOB, using pins #4 and #2.
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If supply voltage is within specifications, but MAF idle voltage is lower than 0.4 volt, the MAF is defective and should be replaced.
4. Increase and decrease engine speed.
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An increase in engine speed/load will increase the voltage output.
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Approximately 3.5 volts should be seen with maximum load and WOT.
If the MAF checks out okay, don't forget to tighten the pin connectors, apply Stabilant 22A, and record your results.
