Test N: The Blower Motor Is Inoperative - EATC

PINPOINT TEST N: THE BLOWER MOTOR IS INOPERATIVE - EATC

N1-N3:

N3-N5:

N5 Continued:

N6-N7:

N7-N8:

N8-N9:

N10-N12:

N12-N13:

N14-N16:

Normal Operation
Under normal operation, the blower motor relay coil receives a ground from the electronic automatic temperature control (EATC) module through circuit CH123 (VT/GN). The coil receives ignition voltage through circuit CBP45 (YE). Voltage is supplied to the relay switch contact through circuit CH402 (YE/GN). When the relay coil is energized, voltage is delivered to the blower motor control module through circuit CH402 (YE/GN)/(BK). Ground for the blower control module is provided by circuit GD116 (BK/VT)/(BK/RD). The EATC module provides a blower target speed signal to the blower control module through circuit VH101 (WH/VT)/(RD) to control the blower speed. The actual blower speed signal is provided to the EATC module through circuit CH102 (YE/BU)/(BN) from the blower control module. Ground for the motor is provided through circuit (BU) from the blower control module.

Possible Causes
- Fuse(s)
- An open in circuit GD116 (BK/VT)/(BK/RD), CH402 (YE/GN)/(BK), CH123 (VT/GN), (BU), VH101 (WH/VT)/(RD), CBP45 (YE) or CH102 (YE/BU)/(BN)
- A short to ground in circuit CH218 (GN/VT)
- A short to voltage in circuit (BU), VH101 (WH/VT)/(RD), CH102 (YE/BU)/(BN) or CH123 (VT/GN)
- A short to ground in circuits CH102 (YE/BU)/(BN) and (BU)
- A short together in circuits CH102 (YE/BU)/(BN) and (BU)
- Blower motor relay
- Blower motor control
- EATC module
- Blower motor