Was the Coolant Fan System Check performed?

B+

Go to Step 2

Refer to Cooling Fan System Check .

1. Disconnect the heater water auxiliary pump connector.
2. Turn the ignition switch to the ON position.
3. Use the DMM to measure the voltage between terminal 2 of the heater water auxiliary pump connector and a known good ground.

Is the measured voltage within the specified value?

B+

Go to Step 4

Go to Step 3

1. Locate an open or a high resistance in circuit X70.
2. Repair the open or the high resistance in circuit X70.

Is the repair complete?

--

Go to Step 7

--

Use the DMM to measure the resistance between terminal 1 of the heater water auxiliary pump connector and a known good ground.

Is the measured resistance within the specified value?

Less than 5 ohms

Go to Step 6

Go to Step 5

1. Locate an open or a high resistance in circuit F75.
2. Repair the open or the high resistance in circuit F75.

Is the repair complete?

--

Go to Step 7

--

Replace the heater water auxiliary pump. Refer to Heater Water Auxiliary Pump Replacement in Engine Cooling.

Is the replacement complete?

--

Go to Step 7

--

1. Connect all connectors and components that were disconnected.
2. Verify the heater water auxiliary pump operates properly?

Does the heater water auxiliary pump operate properly?

--

System OK

Go to Step 1