Circuit/System Testing
- Control module location on the high speed GMLAN serial data circuits
- The control module B+, ignition, ground, communication enable and serial data circuit terminals
- Ignition OFF, disconnect harness connector at the K71 transmission control module (TCM).
- Test for less than 10 Ω between each ground circuit terminal and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- If equipped, ignition ON, verify that a test lamp illuminates between each B+ circuit terminal and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the K71 TCM for a short to ground. If the circuits test normal, replace the K71 TCM.
- If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.
- If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the K71 TCM for a short to ground. If the circuits test normal, replace the K71 TCM.
- If equipped, verify that a test lamp illuminates between the wake-up circuit terminal and ground.
- If the test lamp does not illuminate, test the entire circuit, including the B+ circuit to the K114B hybrid powertrain control module 2, for an open/high resistance or short to ground. If the circuits test normal, replace the K114B hybrid powertrain control module 2.
- Ignition OFF, disconnect the harness connector at the T6 power inverter module.
- Ignition OFF and all vehicle systems OFF, all keys at least 3 meters away from vehicle, all access doors closed. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 1 Ω in each serial data circuit between the K71 TCM and the T6 power inverter module.
- If greater than the specified range, test the serial data circuit for an open/high resistance between the K71 TCM and the T6 power inverter module.
- If all circuits test normal, replace the K71 TCM.
NOTE:
Use the schematic to identify the following: