Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
- Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Disconnect the harness connector at the B75C Multifunction Intake Air Sensor.
- Test for less than 5 Ω between the low reference circuit terminal 3 and ground.
- If 5 Ω or greater
- Ignition OFF, disconnect the harness connector X1 at the K20 Engine Control Module.
- Test for less than 2 Ω in the low reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- Go to next step: If less than 5 Ω
- Ignition ON.
- Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 2 and ground.
- If less than 4.8 V
- Ignition OFF, disconnect the harness connector X3 at the K20 Engine Control Module.
- Test for infinite resistance between the 5 V reference circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the 5 V reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- If greater than 5.2 V
- Ignition OFF, disconnect the harness connector X3 at the K20 Engine Control Module, ignition ON.
- Test for less than 1 V between the 5 V reference circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
- Go to next step: If between 4.8 - 5.2 V
- Verify the scan tool BARO Sensor 2 parameter is greater than 4.7 V.
- If 4.7 V or less
- Ignition OFF, disconnect the harness connector X3 at the K20 Engine Control Module.
- Test for infinite resistance between the signal circuit terminal 4 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the K20 Engine Control Module.
- Go to next step: If greater than 4.7 V
- Connect a 3 A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 3.
- Verify the scan tool BARO Sensor 2 parameter is less than 0.2 V.
- If 0.2 V or greater
- Ignition OFF, remove the jumper wire, disconnect the harness connector X3 at the K20 Engine Control Module, ignition ON.
- Test for less than 1 V between the signal circuit terminal 4 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Ignition Off
- Test for less than 2 Ω in the signal circuit end to end.
- If 2 Ω or greater, repair the open or high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- Go to next step: If less than 0.2 V
- Test or replace the B75C Multifunction Intake Air Sensor.
NOTE:
If the signal circuit is shorted to a voltage the ECM or the sensor may be damaged.