Circuit/System Testing
- Determine the altitude for your area. Refer to Altitude Versus Barometric Pressure . Both sensor values should be within 5 kPa of each other and the Altitude vs. Barometric Pressure table.
- Ignition ON, determine which sensor is out of range by comparing MAP and BARO Sensors kPa parameters with a scan tool.
- Ignition OFF, disconnect the harness connector at the affected sensor.
- Ignition OFF, allow sufficient time for the control module to power down. Test for less than 5 ohms of resistance between the low reference circuit terminal 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 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 sensor parameter is less than 12 kPa.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Install a 3-amp fused jumper wire between the signal circuit and the low reference circuit. Verify the scan tool sensor parameter is greater than 103 kPa for MAP and 126 kPa for BARO.
- If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the affected sensor.