Circuit/System Testing
IMPORTANT:
- The harness connectors for the following sensors are of the same configuration but are not interchangeable. Review the engine controls schematics for the BARO sensor and for the SCIAP sensor and note the circuit colors. Inspect the wiring harness of the BARO sensor for the proper connections. Inspect the wiring harness of the SCIAP sensor for the proper connections.
- You must perform Circuit/System Verification before proceeding with the Circuit/System Testing.
- Ignition OFF, disconnect the harness connector at the SCIAP 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 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.
- Verify the scan tool SC Inlet Pressure parameter is less than 20 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 5-volt reference circuit terminal C and the signal circuit terminal B. Verify the scan tool parameter is greater than 95 kPa.
- If less than the specified range, test the signal circuit for a short to ground, open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test the SCIAP sensor. Refer to Component Testing for instructions.