Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the B75B Mass Air Flow/Intake Air Temperature sensor.
- Ignition OFF and all systems OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 2 Ω between the low reference circuit terminal D and ground.
- If 2 Ω or greater
- Ignition OFF, disconnect the harness connector 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 or high resistance in the circuit.
- If less than 2 Ω replace the K20 Engine Control Module.
- If less than 2 Ω
- Ignition ON, test for 4.8-5.2 V between the intake air temperature sensor signal circuit terminal E and ground.
- If less than 4.8 V
- Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
- Test for infinite resistance between the signal 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 signal 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 at the K20 Engine Control Module.
- Ignition ON, test for less than 1 V between the signal 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.
NOTE:If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.
- If between 4.8-5.2 V
- Test or replace the B75B Mass Air Flow/Intake Air Temperature sensor.