Circuit/System Testing

IMPORTANT: 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.

With the ignition ON, the engine OFF, and the manifold absolute pressure (MAP) sensor disconnected, connect a test lamp between the MAP sensor 5-volt reference circuit and a good ground.
With a DMM, measure the voltage from the probe end of the test lamp to a good ground, for a range of 4.8-5.2 volts.
- If the voltage is less than the specified range, then test the circuit for the following:
  - An Open
  - High resistance
  - A faulty control module
- If the voltage is more than the specified range, then test the circuit for the following:
  - A short to voltage
  - A faulty control module
With the MAP sensor disconnected, use the scan tool to observe the MAP Sensor parameter for a value of less than 45 kPa.
- If the MAP Sensor parameter is more than 45 kPa, then test the MAP sensor signal circuit for the following conditions:
  - A short to 5-volt reference
  - A short battery voltage
  - A faulty control module
With the MAP sensor disconnected, connect a fused jumper wire between the MAP sensor 5-volt reference circuit and the MAP sensor signal circuit. Observe the MAP Sensor parameter for the a value of more than 253 kPa.
- If the MAP Sensor parameter is less than 253 kPa, then test the MAP sensor signal circuit for the following:
  - High resistance
  - A faulty control module
With the ignition OFF, and all electrical accessories OFF, allow sufficient time for the control module to power down. Measure the resistance between the low reference circuit of the MAP sensor connector and a good ground, for a value of less than 5 ohms of resistance.
- If the resistance is more than 5 ohms, then test the low reference circuit for the following:
  - High resistance
  - A faulty control module
    - If all circuits test OK, replace the MAP sensor.