DTC 19

CIRCUIT DESCRIPTION

The ECC Head requests the required blower speed to the Power Module through CKT 760. The power module controls the blower through CKT 65, which is also utilized by the ECC head for blower voltage feedback. The Power Module receives its power from the battery through CKT 2 and is ground through CKT 151, which is shared with the blower motor. Code 19 will set if the requested blower voltage and the blower voltage feedback signal differ by more than 2 volts.

TEST DESCRIPTION

1. If the blower motor works, the problem lies in the blower voltage feedback signal, CKT 65, or in the ECC Head.

2. If the blower voltage agrees with parameter -20, the ECC Head is faulty, otherwise there must be an open CKT 65.

3. If commanded blower voltage and blower voltage feedback are in close agreement, the blower motor must be faulty.

4. If commanded blower voltage is less than 6 volts when HI fan is selected, the ECC Head is faulty.

5. The blower motor will not function as requested by the ECC Head if the Power Module does not receive the proper blower speed control input from the ECC Head through CKT 760.

6. If the Power Module does not receive its required power from the battery and is properly ground the blower speed may be incorrect.

7. If the Power Module receives a valid blower speed but sends to the blower motor a different voltage, the Power Module is faulty.

8. This test determines which circuit is responsible for the Power Module not receiving system voltage. CKT 2 connects the Power Module to the battery and is ground through CKT 151.