Circuit/System Testing
WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF and all vehicle systems OFF, disconnect the X2 harness connector at the K8A Blower Motor Control Module - Auxiliary. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 Ω between the ground circuit terminal 5 and ground.
- If 10 Ω or greater
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 10 Ω
- Ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 6 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF, remove the test lamp.
- Test for less than 2 Ω in the B+ circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF, remove the test lamp.
- Test for infinite resistance between the B+ circuit terminal 6 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Disconnect the X1 harness connector at the K8A Blower Motor Control Module - Auxiliary and disconnect the harness connector at the M8B Blower Motor - Auxiliary.
- Test for infinite resistance between the M8B Blower Motor - Auxiliary B+ terminal A and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, test or replace the M8B Blower Motor - Auxiliary.
- If the test lamp illuminates
- Ignition OFF, remove the test lamp and disconnect the X4 harness connector at the K33 HVAC Control Module, ignition ON.
- Test for less than 1 V between the K8A Blower Motor Control Module - Auxiliary control circuit terminal 3 X2 and ground.
- If 1 V or greater
Repair the short to voltage on the circuit.
- If less than 1 V
- If 1 V or greater
- Ignition OFF.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance
Repair the short to ground on the circuit.
- If infinite resistance
- If less than infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater
Repair the open/high resistance in the circuit.
- If less than 2 Ω
- If 2 Ω or greater
- Connect the harness connectors at the K8A Blower Motor Control Module - Auxiliary and the K33 HVAC Control Module, and disconnect the harness connector at the M8B Blower Motor - Auxiliary, ignition ON and blower ON.
- Verify a test lamp illuminates between the B+ circuit terminal A and ground.
- If the test lamp does not illuminate
- Ignition OFF, disconnect the X1 harness connector at the K8A Blower Motor Control Module - Auxiliary.
- Test for less than 2 Ω in the B+ circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω replace the K8A Blower Motor Control Module - Auxiliary.
- If the test lamp illuminates
- Connect a test lamp between the control circuit terminal B and the B+ circuit terminal A.
- Verify the test lamp becomes progressively brighter as the blower speed is increased and progressively dimmer as the blower speed is decreased.
- If the test lamp does not illuminate
- Ignition OFF, disconnect the X1 harness connector at the K8A Blower Motor Control Module - Auxiliary, ignition ON.
- Test for less than 1 V between the M8B Blower Motor - Auxiliary control circuit terminal B and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω
- Replace the K8A Blower Motor Control Module - Auxiliary.
- Verify the symptom or DTC was corrected.
- If the symptom or DTC was not corrected, replace the K33 HVAC Control Module.
- If the symptom or DTC was corrected
- All OK.
- If the test lamp illuminates, but does not change in brightness
- Ignition OFF, disconnect the X1 harness connector at the K8A Blower Motor Control Module - Auxiliary.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the K8A Blower Motor Control Module - Auxiliary.
- If the test lamp changes in brightness as the blower speed is changed
- Test or replace the M8B Blower Motor - Auxiliary.