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 - Off
- Disconnect the electrical connector:X1 @ T12 Automatic Transmission Assembly
- Connect a test lamp between the test points:Control circuit terminal 15 & Ground
- Ignition - On / Vehicle - In Service Mode
- Perform the scan tool control function:High Side Driver 1 - On and Off
Verify the test lamp turns On and Off.
- If the test lamp is always Off
- Connect the electrical connector:X1 @ T12 Automatic Transmission Assembly
- Ignition/Vehicle - Off
- Disconnect the electrical connector:
- K71 Transmission Control Module
- X1 @ T12 Automatic Transmission Assembly
- Test for infinite resistance between the test points:Control circuit terminal 15 @ 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:Control circuit terminal 15 @ 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:K71 Transmission Control Module
- If the test lamp is always On
- Connect the electrical connector:X1 @ T12 Automatic Transmission Assembly
- Ignition/Vehicle - Off
- Disconnect the electrical connector:
- K71 Transmission Control Module
- X1 @ T12 Automatic Transmission Assembly
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points:Control circuit terminal 15 @ Component harness & Ground
- If 1 V or greater - Repair the short to voltage on the circuit.
- If less than 1 V - Replace the component:K71 Transmission Control Module
- Go to next step: If the test lamp turns On and Off
- Connect the electrical connector: X1 @ T12 Automatic Transmission Assembly
- Verify DTC P0658, P0659 is not set.
- If the DTC is set
Refer to step 14
- Go to next step: If the DTC is not set
- If the DTC is set
- Ignition/Vehicle - Off
- Disconnect the electrical connector:
- K71 Transmission Control Module
- X1 @ T12 Automatic Transmission Assembly
- Test for less than 2 ohms between the test points:
- { P0960, P0962, P0963 } Control circuit terminal 5 @ Component harness & The other end of the circuit @ Control module harness
- { P2718, P2720, P2721 } Control circuit terminal 3 @ Component harness & The other end of the circuit @ Control module harness
- { P2736, P2738, P2739 } Control circuit terminal 4 @ Component harness & The other end of the circuit @ Control module harness
- If 2 ohms or greater
Repair the open/high resistance in the circuit.
- Go to next step: If less than 2 ohms
- Test for infinite resistance between the test points:
- { P0960, P0962, P0963 } Control circuit terminal 5 @ Component harness & Ground
- { P2718, P2720, P2721 } Control circuit terminal 3 @ Component harness & Ground
- { P2736, P2738, P2739 } Control circuit terminal 4 @ Component harness & Ground
- If less than infinite resistance
Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points:
- { P0960, P0962, P0963 } Control circuit terminal 5 @ Component harness & Ground
- { P2718, P2720, P2721 } Control circuit terminal 3 @ Component harness & Ground
- { P2736, P2738, P2739 } Control circuit terminal 4 @ Component harness & Ground
- If 1 V or greater
Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- Ignition/Vehicle - Off
- Remove the component:Transmission Cover
- Connect the electrical connector:X1 @ T12 Automatic Transmission Assembly
- Disconnect the appropriate electrical connector:Q77 Transmission Control Solenoid Valve
- Connect a test lamp between the test points:Control circuit terminal 1 & Ground
- Ignition - On / Vehicle - In Service Mode
- Perform the scan tool control function:High Side Driver 1 - On and Off
Verify the test lamp turns On and Off.
- If the test lamp does not turn On and Off
Replace the component:Automatic Transmission Wiring Harness
- Go to next step: If the test lamp turns On and Off
- If the test lamp does not turn On and Off
- Test for less than 2 ohms between the test points:Control circuit terminal 2 @ Component harness & The other end of the circuit @ Control module harness
- If 2 ohms or greater
Replace the component:Automatic Transmission Wiring Harness
- Go to next step: If less than 2 ohms
- If 2 ohms or greater
- Test for infinite resistance between the test points:Control circuit terminal 2 @ Component harness & Ground
- If less than infinite resistance
Replace the component:Automatic Transmission Wiring Harness
- Go to next step: If infinite resistance
- If less than infinite resistance
- Test or replace the component:Q77 Transmission Control Solenoid Valve