Circuit Description
The starter/generator control module (SGCM) monitors its internal fluid temperature sensors to control the SGCM coolant pump and SGCM cooling fan. The internal fluid temperature sensors of the SGCM are thermistors and are not serviceable. When the internal fluid temperatures are cold, the resistances of the sensors are high and the voltage signals are high. When the internal fluid temperatures are hot, the resistances of the sensors are low and the voltage signals are low. The input parameters are not displayed on the scan tool. The SGCM calculates the estimated temperature of the electronics to interpret the total temperature of the SGCM. This value is displayed on the scan tool.
Conditions for Running the DTC
| • | The engine has been running for 30 seconds. |
| • | The SGCM has received voltage on the ignition 0 voltage circuit. |
| • | The SGCM has turned ON and no configuration DTC are present. |
Conditions for Setting the DTC
The SGCM calculated temperature is over 100°C (212°F).
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
| • | The SGCM functions are limited. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
If there is a restriction of the air flow through the radiator this DTC may set. Ensure that the vehicle front end has at least 1.5 meters (5 feet) of clearance from obstructions to airflow if vehicle is parked.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views | |||
1 | Was the Engine Cooling Diagnostic System Check performed? | Go to Step 2 | |
2 |
Is the DTC set as current DTC? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
3 | Inspect the SGCM coolant level. Is the SGCM coolant level low? | Go to Step 4 | |
4 | Inspect the vehicle front end for obstructions to the radiator. Did you find and correct the condition? | Go to Step 10 | Go to Step 5 |
5 | With a scan tool, command the starter/generator control module (SGCM) cooling fan ON and OFF. Does the SGCM cooling fan turn ON and OFF with each command? | Go to Step 6 | Go to Starter Generator Control Module Cooling Fan Inoperative |
6 | With a scan tool, command the SGCM Coolant Pump ON and OFF. Does the SGCM coolant pump turn ON and OFF with each command? | Go to Step 7 | Go to Starter Generator Control Module Coolant Pump Inoperative |
7 |
Does the SGCM coolant circulate when the SGCM pump is ON? | Go to Step 8 | Go to Generator Control Module Cooling System Draining and Filling |
8 | Inspect for poor connections at the harness connector of the SGCM . Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 9 |
9 |
Important: Perform the programming procedure for the SGCM. Replace the SGCM. Refer to Generator Control Module Replacement in Engine Electrical. Did you complete the replacement? | Go to Step 10 | -- |
10 |
Does the DTC reset? | Go to Step 2 | System OK |
