Circuit/System Testing

WARNING: This page is about a different car, the 2006 Chevrolet Monte Carlo and 2006 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

Turn ON the ignition, with the engine OFF.
Measure the battery voltage.
Disconnect the MAF sensor.
Connect a test lamp between the MAF sensor ignition 1 voltage circuit and a good ground.
With the test lamp still connected, measure for battery voltage between the ignition 1 voltage circuit and a good ground.
- If the voltage is not within 1.5 volts of battery voltage, repair the high resistance in the circuit.
Measure the voltage between the MAF sensor signal circuit and a good ground for 4.9-5.2 volts.
- If the voltage is less than 4.9 volts, test the circuit for a high resistance.
- If the voltage is within 4.9-5.2 volts, test the circuit for a short to the IAT signal circuit or to any other 5-volt reference circuit.
Turn OFF the ignition and all electrical accessories. Allow sufficient time for the control module to power down before taking a resistance measurement.
Measure the resistance between the ground circuit of the MAF sensor and a good ground for less than 5 ohms of resistance. You should measure less than 5 ohms of resistance.
- If the resistance is more than 5 ohms, repair the high resistance in the ground circuit.
Connect the J 38522 to the signal circuit of the MAF sensor and a good ground. See Special Tools .
To set up the variable speed generator, use the switches to set the duty cycle to normal, the frequency to 5 K, and the signal switch to 5 volts.
Start the engine and observe the MAF Sensor parameter for a range of 4,950-5,025 Hertz.
- If the MAF Sensor parameter is not within 4,950-5,025 Hertz, replace the control module.
- If the MAF Sensor parameter is within 4,950-5,025 Hertz, replace the MAF sensor.