Circuit/System Testing

Verify that ECM DTC P0606 is not set.
- If the DTC is set
  Refer to: Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If the DTC is not set
Ignition Off, Disconnect the component: K59 Starter/Generator Control Module X1 connector and the K20 ECM X1 connector.
Using the data communication schematic as a guide, test for less than 1 Ω between the serial data circuits listed below:
- K59 Starter/Generator Control Module X1 connector terminal and K20 ECM X1 connector terminal for circuit 2500
- K59 Starter/Generator Control Module X1 connector terminal and K20 ECM X1 connector terminal for circuit 2501
- If greater than the specified range
  Test the serial data circuit for an open/high resistance condition. If the circuit tests normal, replace the K20 ECM.
- Go to next step: If in the specified range
Verify DTC P06AF is not set.
- If the DTC is set
1. Verify the K59 Starter/Generator Control Module has the latest calibration in Calibration Information.
  - If the K59 Starter/Generator Control Module does not have the latest calibration
  1. Program the control module: K59 Starter/Generator Control Module.
  2. Verify the DTC does not set.
    - If the DTC sets, Replace the component: K59 Starter/Generator Control Module
    - Go to next step: If the DTC does not set
  3. All OK.
  - Go to next step: If the K59 Starter/Generator Control Module has the latest calibration
2. Replace the component: K59 Starter/Generator Control Module.
- Go to next step: If the DTC is not set
All OK.