Circuit/System Testing

P0102

IMPORTANT: If you cannot duplicate the condition, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
1. Inspect the fuse supplying the ignition 1 voltage circuit of the MAF sensor.
   • If the fuse is open, then test the spliced circuits and the components for a short to ground.
2. Disconnect the MAF sensor.
3. Turn ON the ignition, with the engine OFF.
IMPORTANT: Use the J 35616-200  for this test. If the J 35616-200  is not available, use a test lamp that measures more than 20 ohms.
4. Connect a test lamp between the MAF sensor ignition 1 voltage circuit and a good ground.
5. With the test lamp still connected, measure the voltage of the ignition 1 voltage circuit at the test lamp probe, with a DMM connected to a good ground.
   • If the voltage is not within 1.5 volts of battery voltage, repair the high resistance or the open in the circuit.
6. Test the MAF sensor signal circuit for a short to ground, an open or high resistance.
7. Connect a 3-amp fused jumper wire between the ignition 1 voltage circuit of the MAF sensor and the signal circuit of the MAF sensor.
8. Observe the MAF Sensor parameter. for a value of more than 500 g/s.
   • If the MAF Sensor parameter is not more than 500 g/s, test for high resistance in the MAF sensor signal circuit or replace the ECM.
   • If the MAF Sensor parameter is more than 500 g/s, replace the MAF sensor.

P0103

1. Disconnect the MAF sensor connector.
2. Turn ON the ignition, with the engine OFF.
3. Observe the MAF sensor parameters with a scan tool.
   • If the MAF sensor parameters are 0 volts or 0 g/s, replace the MAF sensor.
   • If the MAF sensor parameters are more than 4.7 volts or more than 500 g/s, test the signal circuit for a short to 5-volt reference or battery voltage or a faulty ECM.
IMPORTANT: The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Use the DMM to perform this test. Refer to the DMM User Manual for calibration procedure.
4. Turn OFF the ignition, and all electrical accessories. Allow 60 seconds for the control modules to power down before proceeding and before taking a resistance measurement.
5. Measure the resistance of the low reference circuit at the MAF Sensor connector with a DMM connected to a good ground.
   • If the resistance is more than 2.0 ohms, then test the circuit for a high resistance or a faulty ECM.
   • If the MAF sensor circuits test normal, then replace the MAF sensor.