Pinpoint Test Aa : The Auxiliary Blower Motor Is Inoperative: Notes
Refer to Auxiliary Climate Control , for schematic and connector information.
Normal Operation
The BJB supplies voltage to the auxiliary relay coil and relay switch contacts. The coil receives ground from the HVAC control module if any auxiliary blower speed but OFF is selected. When the relay coil is grounded, the relay is energized and voltage is delivered to the auxiliary blower motor speed control. The auxiliary blower motor speed control has a dedicated ground. Voltage and ground for the auxiliary blower motor are provided through the auxiliary blower motor speed control. The HVAC control module sends a Pulse Width Modulated(PWM) signal to the auxiliary blower motor speed control to determine the desired auxiliary blower motor speed. The auxiliary blower motor speed control varies the ground feed for the auxiliary blower motor to control the speed.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B10B0:12 | Rear Blower Fan Relay: Circuit Short to Battery | This DTC sets when the HVAC control module senses voltage on the auxiliary relay coil ground circuit when the HVAC control module is grounding the circuit, indicating a short directly to voltage. Blower motor will not run. |
| B10B0:13 | Rear Blower Fan Relay: Circuit Open | This DTC sets when the HVAC control module senses no voltage on the auxiliary relay coil ground circuit, indicating an open circuit. Blower motor will not run. |
| B10BA:12 | Rear Blower Control: Circuit Short To Battery | This DTC sets when the HVAC control module senses excessive voltage on the auxiliary blower motor speed control PWM circuit, indicating a short directly to voltage. Blower motor will not run. |
| B10BA:14 | Rear Blower Control: Circuit Short To Ground or Open | This DTC sets when the HVAC control module senses no voltage on the auxiliary blower motor speed control PWM circuit, indicating an open or a short directly to ground. Blower motor will be inoperative. |
Possible Sources
- Fuse
- Wiring, terminals or connectors
- Auxiliary blower motor
- Auxiliary blower motor relay
- Auxiliary blower motor speed control
- HVAC control module