Circuit Description
The starter generator control module (SGCM) uses the interlock circuit to monitor the plugs and connectors for hybrid system function. The interlock indicates the state of the connectors in the 120 voltage circuits. In the SGCM, the primary side of the transformer is connected to a low frequency oscillator circuit. When the loop is complete, the shorted secondary reduces the oscillator voltage, and a comparator senses this as a good and complete interlock loop. If the loop is open, the oscillator amplitude increases and the comparator senses this as a problem.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0A0A High Voltage System Interlock Circuit
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | All conditions met for the vehicle to enter normal or continuous modes. |
| • | The SGCM run time greater than 5 seconds. |
Action Taken When the DTC Sets
| • | The SGCM will record the operating conditions presents when the DTC set as Failure Records data only. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
Conditions for Clearing the DTC
| • | The Conditions for Setting the DTC are no longer present. |
| • | A history DTC will clear after 40 malfunction free ignition cycles. |
| • | The SGCM receives the clear code command from the scan tool. |
Diagnostic Aids
Ensure that all connectors are connected properly.
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Cigar Lighter/Power Outlet Schematics Connector End View Reference: Power Outlet Connector End Views | |||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||
2 |
Is continuity present? | Go to Step 6 | Go to Step 3 | ||||||
3 | Test the high voltage interlock loop signal 1 and the high voltage interlock loop signal 2 for the following:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 8 | Go to Step 4 | ||||||
4 | Inspect for poor connections at the appropriate harness connector of the shorted high voltage outlet. Refer to Circuit Testing and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 7 | Go to Step 5 | ||||||
5 | Replace the appropriate outlet. Refer to the following in Engine Electrical: Did you complete the replacement? | Go to Step 8 | -- | ||||||
6 | Inspect for poor connections at the harness connector of the SGCM. Refer to Circuit Testing and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 8 | Go to Step 7 | ||||||
7 | Replace the SGCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 8 | -- | ||||||
8 |
Does the DTC reset? | Go to Step 2 | System OK | ||||||
