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 @ T12 Automatic Transmission Assembly
- Ignition - On / Vehicle - In Service Mode
- Test for 8.3 to 9.6 V between the test points:9 V Reference circuit terminal 18 & Ground
- If less than 8.3 V
- Ignition/Vehicle - Off
- Disconnect the electrical connector:K71 Transmission Control Module
- Test for infinite resistance between the test points:9 V Reference circuit terminal 18 @ 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:9 V Reference circuit terminal 18 @ 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 greater than 9.6 V
- Ignition/Vehicle - Off
- Disconnect the electrical connector:K71 Transmission Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points: 9 V Reference circuit terminal 18 @ 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 between 8.3 and 9.6 V
- Ignition/Vehicle - Off
- Install & Setup - EL-38522 Variable Signal Generator
- Voltage - 5 V
- Frequency - 300 Hz
- Duty Cycle - 50%
- Black lead @ Ground
- Red lead @ Signal circuit terminal 6
- Ignition - On / Vehicle - In Service Mode
- Verify the scan tool parameter:Transmission Input Speed = 290 to 310 RPM
- If not between 290 and 310 RPM
- Ignition/Vehicle - Off
- Disconnect the electrical connector:K71 Transmission Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points:Signal circuit terminal 6 @ 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
- Test for infinite resistance between the test points:Signal circuit terminal 6 @ 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:Signal circuit terminal 6 @ 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
- Go to next step: If between 290 and 310 RPM
- Remove the component:Control Valve Body Cover
- Connect the electrical connector:X1 @ T12 Automatic Transmission Assembly
- Disconnect the electrical connector:B14C Transmission Input Shaft Speed Sensor
- Install & Setup - EL-38522 Variable Signal Generator
- Voltage - 5 V
- Frequency - 300 Hz
- Duty Cycle - 50%
- Black lead @ Ground
- Red lead @ Signal circuit terminal 1
- Ignition - On / Vehicle - In Service Mode
- Verify the scan tool parameter:Transmission Input Speed = 290 to 310 RPM
- If not between 290 and 310 RPM
Replace the component:Automatic Transmission Wiring Harness
- Go to next step: If between 290 and 310 RPM
- If not between 290 and 310 RPM
- Test for 8.3 to 9.6 V between the test points:9 V Reference circuit terminal 2 & Ground
- If not between 8.3 and 9.6 V
Replace the component:Automatic Transmission Wiring Harness
- Go to next step: If between 8.3 and 9.6 V
- If not between 8.3 and 9.6 V
- Test or replace the component:B14C Transmission Input Shaft Speed 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.