Schematic Reference: Engine Cooling Schematics

Connector End View Reference: Cooling System Connector End Views

DEFINITION: The afterboil coolant pump does not operate under certain conditions.

Did you perform the Engine Cooling Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Engine Cooling

1. Start the engine.
2. Turn ON the HVAC blower.
3. Set temperature to 90°F.

Does the afterboil coolant pump operate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, command the Water Pump Control ON in climate control panel (CCP) special functions, miscellaneous test.

Does the afterboil coolant pump operate?

Go to Step 11

Go to Step 4

1. Disconnect the afterboil relay.
2. Connect a test lamp between the control circuit of the afterboil relay and the coil supply voltage circuit of the afterboil relay.
3. With a scan tool command the Water Pump Control ON and OFF.

Does the test lamp illuminate?

Go to Step 5

Go to Step 6

Connect a 5 amp fused jumper wire between the battery positive voltage circuit of the afterboil relay and the afterboil coolant pump supply voltage circuit of the afterboil relay.

Does the afterboil coolant pump operate?

Go to Step 13

Go to Step 9

Test the control circuit of the afterboil relay for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 7

Test the battery positive voltage circuit of the afterboil relay for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 8

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

Did you find and correct the condition?

Go to Step 14

Go to Step 11

Test the voltage supply circuit of the afterboil coolant pump for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 10

Test the ground circuit of the afterboil coolant pump for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 12

Replace the HVAC Control Module. Refer to HVAC Control Module Replacement in HVAC Systems - Automatic.

Did you complete the replacement?

Go to Step 14

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Replace the afterboil coolant pump. Refer to Afterboil Coolant Pump Replacement .

Did you complete the replacement?

Go to Step 14

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Replace the afterboil relay.

Did you complete the replacement?

Go to Step 14

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3