Circuit/System Testing
WARNING: This page is about a different car, the 2022 Cadillac CT4. 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
- Ignition - On / Vehicle - In Service Mode
- Test for 8.6 to 9.2 V between the test points: 9 V Reference circuit terminal 7 @ T12 Automatic Transmission (harness side) & Ground
- If less than 8.6 V
- Disconnect the electrical connector: K71 Transmission Control Module
- Test for infinite resistance between the test points: 9 V Reference circuit terminal 7 @ T12 Automatic Transmission (harness side) & 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 7 @ T12 Automatic Transmission (harness side) & The other end of the circuit
- 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 9.2 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 7 @ T12 Automatic Transmission (harness side) & 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 8.6 and 9.2 V
- Verify the scan tool parameter:
- { P17F5, P17F6, P17F7 } Transmission Park Valve Position Sensor = Less than 0.4 V
- { P17FA, P17FB, P17FC } Transmission Park Valve Position Sensor 2 = Less than 0.4 V
- If 0.4 V or greater
- Ignition/Vehicle - Off
- Disconnect the electrical connector: K71 Transmission Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 0.4 V between the test points:
- { P17F5, P17F6, P17F7 } Signal circuit terminal 5 @ T12 Automatic Transmission (harness side) & Ground
- { P17FA, P17FB, P17FC } Signal circuit terminal 6 @ T12 Automatic Transmission (harness side) & Ground
- If 0.4 V or greater - Repair the short to voltage on the circuit.
- If less than 0.4 V - Replace the component: K71 Transmission Control Module
- Go to next step: If less than 0.4 V
- Connect a 3 A fused jumper wire between the test points:
- { P17F5, P17F6, P17F7 } Signal circuit terminal 5 & 9 V Reference circuit terminal 7
- { P17FA, P17FB, P17FC } Signal circuit terminal 6 & 9 V Reference circuit terminal 7
- Verify the scan tool parameter:
- { P17F5, P17F6, P17F7 } Transmission Park Valve Position Sensor = Greater than 4.8 V
- { P17FA, P17FB, P17FC } Transmission Park Valve Position Sensor 2 = Greater than 4.8 V
- If less than 4.8 V
- Ignition/Vehicle - Off & Remove - Jumper wire (s)
- Disconnect the electrical connector: K71 Transmission Control Module
- Test for infinite resistance between the test points:
- { P17F5, P17F6, P17F7 } Signal circuit terminal 5 @ Component harness & Ground
- { P17FA, P17FB, P17FC } 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:
- { P17F5, P17F6, P17F7 } Signal circuit terminal 5 @ Component harness & The other end of the circuit @ Control module harness
- { P17FA, P17FB, P17FC } 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 greater than 4.8 V
- Ignition/Vehicle - Off & Remove - Jumper wire (s)
- Remove the component: Automatic Transmission Fluid Pan
- Connect the electrical connector: X1 @ T12 Automatic Transmission
- Disconnect the electrical connector: B316 Transmission Park Valve Position Switch
- Ignition - On / Vehicle - In Service Mode
- Verify the scan tool parameter:
- { P17F5, P17F6, P17F7 } Transmission Park Valve Position Sensor = Less than 0.4 V
- { P17FA, P17FB, P17FC } Transmission Park Valve Position Sensor 2 = Less than 0.4 V
- If 0.4 V or greater
Replace the component: Automatic Transmission Wiring Harness
- Test for 8.6 to 9.2 V between the test points: 9 V Reference circuit terminal 2 & Ground
- If not between 8.6 and 9.2 V
Replace the component: Automatic Transmission Wiring Harness
- Go to next step: If between 8.6 and 9.2 V
- If not between 8.6 and 9.2 V
- Connect a 3 A fused jumper wire between the test points:
- { P17F5, P17F6, P17F7 } Signal circuit terminal 3 & 9 V Reference circuit terminal 2
- { P17FA, P17FB, P17FC } Signal circuit terminal 4 & 9 V Reference circuit terminal 2
- Verify the scan tool parameter:
- { P17F5, P17F6, P17F7 } Transmission Park Valve Position Sensor = Greater than 4.8 V
- { P17FA, P17FB, P17FC } Transmission Park Valve Position Sensor 2 = Greater than 4.8 V
- If less than 4.8 V
Replace the component: Automatic Transmission Wiring Harness
- Go to next step: If 4.8 V or greater
- Test or replace the component: B316 Transmission Park Valve Position Switch
NOTE:
When the following connector is disconnected, the ignition cannot be turned off due to lack of a valid park input to the TCM. If the ignition needs to be turned off, the connector will need to be reconnected.