Circuit/System Testing
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector:B9 Ambient Air Temperature Sensor
- Test for less than 10 ohms between the test points:Low Reference circuit terminal B or 2 & Ground
- If 10 ohms or greater
- Disconnect the electrical connector:K20 Engine Control Module
- Test for less than 2 ohms between the test points:Low Reference circuit terminal B or 2 @Component harness & The other end of the circuit
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Replace the component:K20 Engine Control Module
- If less than 10 ohms
- Ignition - On / Vehicle - In Service Mode
- Verify the scan tool parameter:Ambient Air Temperature=Less than -34°C (-30°F)
- If -34°C (-30°F) or warmer
- Ignition/Vehicle - Off
- Disconnect the electrical connector:K20 Engine Control Module
- Test for infinite resistance between the test points:Signal circuit terminal A or 1@Component harness & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- If infinite resistance - Replace the component:K20 Engine Control Module
- If -35°C (-31°F) or colder
- Connect a 3 A fused jumper wire between the test points:Signal circuit terminal A or 1 & Low Reference circuit terminal B or 2
- Verify the scan tool parameter:Ambient Air Temperature=Greater than 143°C (290°F)
- If 143°C (290°F) or colder
- Ignition/Vehicle - Off & Remove - Jumper wire(s)
- Disconnect the electrical connector:K20 Engine Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points:Signal circuit@Component harness & Ground
- If 1 V or greater - Repair the short to voltage on the circuit.
- If less than 1 V
- Ignition/Vehicle - Off
- Test for less than 2 ohms between the test points:Signal circuit@Component harness & The other end of the circuit
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Replace the component:K20 Engine Control Module
- If 144°C (291°F) or warmer
- Test or replace the component:B9 Ambient Air Temperature Sensor
NOTE:
It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.