Circuit/System Testing
WARNING: This page is about a different car, the 2019 Chevrolet Malibu. 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:X1, X2 @ E40 Electrical Auxiliary Heater
- Test for less than 10 ohms between the test points:Ground circuit terminal 2 X2 & Ground
- If 10 ohms or greater
- Test for less than 2 ohms between the test points:Ground circuit terminal & The other end of the circuit
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Repair the open/high resistance in the ground connection.
- Go to next step: If less than 10 ohms
- Verify a test lamp turns On between the test points:B+ circuit terminal 1 X2 & Ground
- If the test lamp does not turn On and the circuit fuse is OK
- Ignition/Vehicle - Off & Remove - Test lamp
- Test for less than 2 ohms between the test points:B+ circuit terminal 1 X2 & The other end of the circuit
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
- If the test lamp does not turn On and the circuit fuse is open
- Ignition/Vehicle - Off
- Test for infinite resistance between the test points:B+ circuit terminal 1 X2 & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- If infinite resistance - Replace the component:E40 Electrical Auxiliary Heater
- Go to next step: If the test lamp turns On
- Ignition - On / Vehicle - In Service Mode
- Verify a test lamp turns On between the test points:Ignition circuit terminal 2 X1 & Ground
- If the test lamp does not turn On and the circuit fuse is OK
- Ignition/Vehicle - Off & Remove - Test lamp
- Test for less than 2 ohms between the test points:Ignition circuit terminal 2 X1 & The other end of the circuit
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
- If the test lamp does not turn On and the circuit fuse is open
- Ignition/Vehicle - Off
- Test for infinite resistance between the test points:Ignition circuit terminal 2 X1 & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- If infinite resistance - Replace the component:E40 Electrical Auxiliary Heater
- Go to next step: If the test lamp turns On
- Ignition/Vehicle - Off & Remove - Test lamp
- Disconnect the electrical connector.X2 @ K33 HVAC Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 0.3 V between the test points:Control circuit terminal 7 & Ground
- If 0.3 V or greater - Repair the short to voltage on the circuit.
- Go to next step: If less than 0.3 V
- Ignition/Vehicle - Off
- Test for infinite resistance between the test points:Control circuit terminal 7 & 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:Control circuit terminal 7 @ Control module harness & Control circuit terminal 1 X1 @ Component harness
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- Go to next step: If less than 2 ohms
- Replace the component:E40 Electrical Auxiliary Heater
- Ignition - On / Vehicle - In Service Mode
- Verify DTC B048D is not set.
- If DTC B048D is set
Replace the component:K33 HVAC Control Module
- If DTC B048D is set
- If DTC B048D is not set
All OK.
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.