DTC P0103 - Mass Airflow (MAF) Sensor: Condition

DTC P0103 indicates MAF signal was more than 4.70 volts sometime during normal engine operation. Possible causes for this fault are as follows:

• Restricted MAF sensor screen.
• MAF SIG circuit shorted to VPWR.
• Faulty MAF sensor or connector.
• Faulty PCM.

1) Check MAF Signal High Input To PCM  Ensure air induction system is okay. Repair if necessary. Start engine and allow to idle. If engine does not idle smoothly, repair cause of rough idle condition before continuing. With scan tool connected, raise engine speed to 1500 RPM and return to idle. Access MAF PID. PID reading should be more than 4.60 volts. Turn ignition off. Disconnect MAF sensor. Start engine and allow to idle. Access MAF PID. If PID voltage reading does not drop to less than 0.39 volt, go to next step. If PID voltage reading does drop to less than 0.39 volt, replace MAF sensor.

2) Check MAF SIG Circuit For Short To Power  Leave ignition off and MAF sensor disconnected. Disconnect PCM 104-pin connector and inspect for damage. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between test pin No. 88 (MAF SIG) and test pins No. 24 and 103 at breakout box. If voltage is less than 10.5 volts, go to next step. If voltage is 10.5 volts or more, repair MAF SIG circuit short to power.

3) Check MAF SIG Circuit For Short To Power In PCM  Leave ignition off and MAF sensor disconnected. Disconnect scan tool from DLC (if applicable). Measure resistance between test pin No. 88 (MAF SIG) and test pins No. 71 and 97 (VPWR) at breakout box. If resistance is more than 10,000 ohms, replace PCM and repeat QUICK TEST. If resistance is 10,000 ohms or less, repair short between MAF SIG and VREF circuit. Repeat QUICK TEST.