Schematic Reference: Hybrid Cooling Schematics

Connector End View Reference: Hybrid Cooling Connector End Views

DEFINITION: The starter generator control module (SGCM) coolant pump does not operate under certain conditions.

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

SGCM and red box are the same part.

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, command the SGCM pump speed ON in powertrain special functions, SGCM output controls.

Does the SGCM coolant pump operate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

1. Disconnect the red box cool pump relay.
2. Connect a test lamp between the control circuit and the coil supply voltage circuit of the red box cool pump relay.
3. With a scan tool command the SGCM pump speed ON and OFF.

Does the test lamp illuminate?

Go to Step 4

Go to Step 5

Connect a 10-amp fused jumper wire between the battery positive voltage circuit and the coolant pump supply voltage circuit of the after-boil relay.

Does the after-boil coolant pump operate?

Go to Step 12

Go to Step 8

Test the control circuit of the red box cool pump relay for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 6

Test the battery positive voltage circuit of the red box cool pump relay for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 7

Test the voltage supply circuit of the red box coolant pump for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 10

Test the voltage supply circuit of the red box coolant pump for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 9

Test the ground circuit of the red box coolant pump for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 11

Replace the SGCM (red box). Refer to Generator Control Module Cooling System Draining and Filling .

Did you complete the replacement?

Go to Step 13

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Replace the red box coolant pump. Refer to Generator Control Module Coolant Pump Replacement .

Did you complete the replacement?

Go to Step 13

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Replace the red box relay.

Did you complete the replacement?

Go to Step 13

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2