Circuit/System Testing
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector : B75C Multifunction Intake Air Sensor
- Ignition - On / Vehicle - In Service Mode
- Verify a test lamp turns On between the test points: Ignition circuit terminal 5 & Ground
- If the test lamp does not turn On
- Ignition/Vehicle - Off & Remove - Test lamp
- Disconnect the appropriate electrical connector : K20 Engine Control Module
- Test for infinite resistance between the test points: Ignition circuit terminal 5 @ Component harness & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- Test for less than 2 ohms between the test points: Ignition circuit terminal 5 @ Component harness & The other end of the circuit @ Control module harness
- 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
- Go to next step: If the test lamp turns On
- Replace the component: B75C Multifunction Intake Air 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.