Circuit/System Testing
- Verify the integrity of the air induction system by inspecting for the following conditions:
- Damaged components
- Loose or improper installation
- An air flow restriction
- A cracked or restricted MAP sensor vacuum hose
- An intake manifold leak
- Ignition OFF, disconnect the harness connector at the MAP sensor.
- Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal A and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground.
- If less than the specified range, test the 5-volt reference circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Verify the scan tool MAP parameter is less than 12 kPa.
- If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM.
- Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference terminal C. Verify the scan tool MAP parameter is greater than 103 kPa.
- If less than the specified range, test the signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the MAP sensor.