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 & All vehicle systems - Off
- Disconnect the electrical connector: X1 @ T12 Automatic Transmission
- Test for less than 10 ohms between the test points: Ground circuit terminal 17 @ X1 (harness side) & Ground
- If 10 ohms or greater
- Disconnect the ground connection: G103
- Test for less than 2 ohms between the test points: Ground circuit terminal 17 @ X1 (harness side) & G103
- 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
- Ignition - On / Vehicle - In Service Mode
- Verify a test lamp turns On between the test points: B+ circuit terminal 10 @ X1 (harness side) & Ground
- If the test lamp does not turn On and the circuit fuse is OK
- Remove - Test Lamp
- Test for less than 2 ohms between the test points: B+ circuit terminal 10 @ X1 (harness side) & Output terminal @ X50A
- 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
- Remove - Test Lamp
- Test for infinite resistance between the test points: B+ circuit terminal 10 @ X1 (harness side) & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- If infinite resistance - Replace the component:
- Go to next step: If the test lamp turns On
- Disconnect the electrical connector: K71 Transmission Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points: Control circuit terminal 18 @ X1 (harness side) & Ground
- If greater than 1 V
Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- If greater than 1 V
- Test for greater than 5 ohms between the test points: Control circuit terminal 18 @ X1 & Ground
- If less than 5 ohms
Repair the short to ground on the circuit.
- Go to next step: If greater than 5 ohms
- If less than 5 ohms
- Test for less than 5 ohms between the test points: Control circuit terminal 18 @ X1 & The other end of the circuit
- If greater than 5 ohms
Repair the open/high resistance in the circuit.
- Go to next step: If less than 5 ohms
- If greater than 5 ohms
- Remove the component: Automatic Transmission Fluid Pan
- Disconnect the component: G5 Automatic Transmission Auxiliary Fluid Pump
- Connect the electrical connector: X1 @ T12 Automatic Transmission
- Test for battery voltage between the test points: B+ circuit terminal 1 & Ground circuit terminal 3 @ G5 Automatic Transmission Auxiliary Fluid Pump
- If less than battery voltage
Replace the component: Automatic Transmission Wiring Harness
- Go to next step: If battery voltage
- If less than battery voltage
- Test for less than 5 ohms between the test points: Control circuit terminal 4 & The other end of the circuit
- If greater than 5 ohms
Replace the component: Automatic Transmission Wiring Harness
- Go to next step: If less than 5 ohms
- If greater than 5 ohms
- Test for less than 5 ohms between the test points: Control circuit terminal 3 & The other end of the circuit
- If greater than 5 ohms
Replace the component: Automatic Transmission Wiring Harness
- Go to next step: If less than 5 ohms
- If greater than 5 ohms
- Test or replace the component: G5 Transmission Fluid Pump - Electric/Auxiliary
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.
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.