Circuit/System Testing
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: X1 @ T12 Automatic Transmission
- Test for less than 10 ohms between the test points: Low Reference circuit terminal 26 & Ground
- If 10 ohms or greater
- Disconnect the electrical connector: K71 Transmission Control Module
- Test for less than 2 ohms between the test points: Low Reference circuit terminal 26@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 less than 10 ohms
- Ignition - On/Vehicle - In Service Mode
- Verify the scan tool parameter: Transmission Fluid Temperature = Colder than -39°C (-38°F)
- If -39°C (-38°F) or warmer
- Ignition/Vehicle - Off
- Disconnect the electrical connector: K71 Transmission Control Module
- Test for infinite resistance between the test points: Signal circuit terminal 13@Component harness & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- If infinite resistance - Replace the component: K71 Transmission Control Module
- Go to next step: If colder than -39°C (-38°F)
- Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 13 & Low Reference circuit terminal 26
- Verify the scan tool parameter: Transmission Fluid Temperature = Warmer than 149°C (300°F)
- If 149°C (300°F) or colder
- Ignition/Vehicle - Off & Remove - Jumper wire(s)
- 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 13@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 less than 2 ohms between the test points: Signal circuit terminal 13@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 warmer than 149°C (300°F)
- Ignition/Vehicle - Off
- Connect the electrical connector: X1@T12 Automatic Transmission
- Remove the component: Automatic Transmission Fluid Pan
- Disconnect the electrical connector: X176
- Ignition - On/Vehicle - In Service Mode
- Test for 4.8 to 5.2 V between the test points: Signal circuit terminal 14 & Low Reference terminal 13
- If not between 4.8 and 5.2 V
Replace the appropriate component: Automatic Transmission Wiring Harness
- Go to next step: If between 4.8 and 5.2 V
- If not between 4.8 and 5.2 V
- Remove the component: Control Valve Assembly
- Connect the electrical connector: X176
- Disconnect the electrical connector: B13 Automatic Transmission Fluid Temperature Sensor
- Test for 4.8 to 5.2 V between the test points: Signal circuit terminal 2 & Low Reference circuit terminal 1
- If not between 4.8 and 5.2 V
Replace the appropriate component: Automatic Transmission Wiring Harness
- Go to next step: If between 4.8 and 5.2 V
- If not between 4.8 and 5.2 V
- Test or replace the component: B13 Automatic Transmission Fluid Temperature 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.
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.
NOTE:
Testing for steps 3 to 7 is performed on the control module K71 side of the harness connector.
NOTE:
Testing for steps 13 to 17 is performed on the control module K71 side of the harness connector.