Test O: The Blower Motor Is Inoperative - DATC/EATC
PINPOINT TEST O: THE BLOWER MOTOR IS INOPERATIVE - DATC/EATCO1-O3:
O3-O5:
O5-O7:
O8-O9:
O10-O12:
O13-O16:
O16-O18:
Normal Operation
Under normal operation, the blower motor relay coil receives a ground from the electronic automatic temperature control (EATC) or dual automatic temperature control (DATC) module through circuit CH123 (VT/GN). The coil receives ignition voltage through circuit CBP23 (BN/YE). Voltage is supplied to the relay switch contact through circuit SBB04 (GN/RD). When the relay coil is energized, voltage is delivered to the blower motor control module through circuit CH402 (YE/GN). Ground for the blower control module is provided by circuit GD115 (BK/GY). The DATC/EATC module provides a pulsed ground to the blower control module through circuit VH101 (WH/VT) to control the blower speed. Voltage for the motor is provided through circuit CH218 (GN/VT) from the blower control module. Ground for the motor is provided through circuit VH301 (YE/BU) from the blower control module.
Possible Causes
- Fuse(s)
- An open in circuit GD115 (BK/GY), CH402 (YE/GN), CH123 (VT/GN), CH218 (GN/VT), VH301 (YE/BU), VH101 (WH/VT), CBP23 (BN/YE) or SBB04 (GN/RD)
- A short to ground in circuit CH218 (GN/VT)
- A short to voltage in circuit VH301 (YE/BU), VH101 (WH/VT) or CH123 (VT/GN)
- A short together in circuits CH218 (GN/VT) and VH301 (YE/BU)
- Blower motor relay
- Blower motor control
- DATC/EATC module
- Blower motor