Circuit/System Testing
NOTE:
You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, and all vehicle systems OFF, it may take up to 2 min. for all vehicle systems to power down. Disconnect the harness connector at the B111B Turbocharger Boost/Intake Air Temperature sensor.
- Test for less than 2Ω between the intake air temperature Sensor 3 low reference circuit terminal 1 and ground.
- If 2Ω or greater
- Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
- Test for less than 2Ω in the low reference circuit end to end.
- If 2Ω or greater, repair the open or high resistance in the circuit.
- If less than 2Ω replace the K20 Engine Control Module.
- If less than 2Ω
- Ignition ON, test for 4.8-5.2V between the intake air temperature signal 3 signal circuit terminal 2 and ground.
- If less than 4.8V
- 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 2Ω in the signal circuit end to end.
- If 2Ω or greater, repair the open/high resistance in the circuit.
- If less than 2Ω, replace the K20 Engine Control Module.
- If greater than 5.2V
- Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
- Ignition ON, test for less than 1V between the signal circuit and ground.
- If 1V or greater, repair the short to voltage on the circuit.
- If less than 1V, 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 4.8-5.2V
- Ignition ON, verify the scan tool IAT Sensor 3 parameter is colder than -39°C (-38°F).
- If warmer than -39°C (-38°F).
- Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
- Test for infinite resistance between the signal circuit terminal 2 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2Ω in the signal circuit end to end.
- If 2Ω or greater, repair the open/high resistance in the circuit.
- If less than 2Ω, replace the K20 Engine Control Module.
- If colder than -39°C (-38°F).
- Ignition OFF, install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1.
- Verify the scan tool IAT Sensor 3 parameter is warmer than 148°C (298°F).
- If colder than 148°C (298°F).
- Ignition OFF, remove the jumper wire, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
- Test for less than 1V between the signal circuit and ground.
- If 1V or greater, repair the short to voltage on the circuit.
- If less than 1V
- Ignition OFF.
- Test for less than 2Ω in the signal circuit end to end.
- If 2Ω or greater, repair the open/high resistance in the circuit.
- If less than 2Ω, replace the K20 Engine Control Module.
- If warmer than 148°C (298°F).
- Test or replace the B111B Turbocharger Boost/Intake Air Temperature sensor.