Circuit/System Testing

P0107

1. With the ignition ON, the engine OFF, and the MAP sensor disconnected, use a DMM and measure for a voltage range of 4.8-5.1 volts between the MAP sensor 5-volt reference circuit and a good ground.
   • If the voltage is less than 4.8 volts, then test the 5-volt reference circuit for an open, high resistance, or short to ground.
2. Connect a 3-amp J 36169-A  between the 5-volt reference voltage circuit of the MAP sensor and the signal circuit of the MAP sensor. With a scan tool, observe the MAP Sensor parameter for a value of more than 250 kPa or 4.8 volts.
   • If the MAP Sensor parameter is not more than 250 kPa or 4.8 volts, test the signal circuit for an open, a short to ground or a faulty ECM.
   • If the MAP Sensor parameter is more than 250 kPa or 4.8 volts, replace the MAP sensor.

P0108

1. With the ignition ON, the engine OFF, and the MAP sensor disconnected, use a DMM and measure for a voltage of less than 0.4 volt between the MAP sensor signal circuit and a good ground.
   • If the voltage is more than 0.4 volt, test the signal circuit for a short to 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 the calibration procedure.
2. Turn OFF the ignition, and all electrical accessories. Allow 60 seconds for the control module to power down before proceeding and before taking a resistance measurement. Measure the resistance of the low reference circuit at the MAP sensor connector with a DMM connected to a good ground.
   • If the resistance is more than 2 ohms, then test the circuit for a high resistance or a faulty ECM.
   • If the MAP sensor circuits test normal, then replace the MAP sensor.