Pinpoint Test K : The Blower Motor Is Inoperative
- Automatic Climate Control System for schematic and connector information.
Normal Operation and Fault Conditions
Air Handling, REFER to: Climate Control System - Vehicles With: Electronic Automatic Temperature Control (EATC) - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition HVAC B10AF:11 Blower Fan Relay: Circuit Short To Ground This DTC sets when the HVAC control module senses no voltage change on the blower motor relay coil control circuit when the module attempts to engage the relay, indicating a short directly to ground. The blower motor is inoperative. HVAC B10AF:15 Blower Fan Relay: Circuit Short To Battery Or Open This DTC sets when the HVAC control module senses no ground on the blower motor relay coil control circuit when the module attempts to engage the relay, indicating an open circuit or a short directly to voltage. The blower motor is inoperative when the relay control circuit is open. The blower motor is always on when the relay control circuit is shorted to voltage. HVAC B10B9:12 Blower Control: Circuit Short To Battery This DTC sets when the HVAC control module senses excessive voltage on the blower motor speed control PWM circuit, indicating a short directly to voltage. The blower motor is inoperative. HVAC B10B9:14 Blower Control: Circuit Short To Ground Or Open This DTC sets when the HVAC control module senses no voltage on the blower motor speed control PWM circuit, indicating an open or a short directly to ground. The blower motor is inoperative. Possible Sources
- Wiring, terminals or connectors
- Blower motor relay
- Blower motor
- Blower motor speed control
- HVAC control module
Visual Inspection and Pre-checks
- Inspect BJB fuse 6 (40A).
- NOTE: Use the correct probe adapter(s) when making measurements. Failure to. Use the correct probe adapter(s) may damage the connector.
- K1 CHECK THE BLOWER MOTOR RELAY FUNCTIONALITY
- Ignition OFF.
- Disconnect Blower motor relay.
- Carry out the component test on the blower motor relay. Refer to OEM WIRING DIAGRAMS COMPONENT TESTING for schematic and connector information.
Did the relay pass the component test?
Yes GO to K2 No INSTALL a new blower motor relay. - K2 CHECK THE BLOWER MOTOR RELAY COIL GROUND CIRCUIT FOR AN OPEN
Is the resistance less than 3 ohms?
Yes GO to K3 No REPAIR the circuit. - K3 CHECK THE BLOWER MOTOR RELAY SWITCH CONTACT SUPPLY VOLTAGE
Is the voltage greater than 11 volts?
Yes GO to K4 No VERIFY BJB fuse 6 (40A) is OK. If OK, REPAIR the circuit. If not OK, REFER to OEM Electrical Wiring Diagram Introduction to identify the possible causes of the circuit short. - K4 CHECK THE BLOWER MOTOR RELAY COIL CONTROL CIRCUIT FOR A SHORT TO GROUND
- Disconnect HVAC control module C294A.
Is the resistance greater than 10, 000 ohms?
Yes GO to K5 No REPAIR the circuit. - K5 CHECK THE BLOWER MOTOR RELAY COIL CONTROL CIRCUIT FOR AN OPEN
- Measure:
Positive Lead Measurement / Action Negative Lead Blower motor relay socket 1 Refer to C294A-11
Is the resistance less than 3 ohms?
Yes GO to K6 No REPAIR the circuit. - Measure:
- K6 CHECK THE BLOWER MOTOR SPEED CONTROL VOLTAGE CIRCUIT FOR AN OPEN
- Disconnect Blower motor speed control C297A.
- Measure:
Positive Lead Measurement / Action Negative Lead Blower motor relay socket 5 Refer to C297A-4
Is the resistance less than 3 ohms?
Yes GO to K7 No REPAIR the circuit. - K7 CHECK THE BLOWER MOTOR SPEED CONTROL GROUND CIRCUIT FOR AN OPEN
- Measure:
Positive Lead Measurement / Action Negative Lead Refer to C297A-2 Ground
Is the resistance less than 3 ohms?
Yes GO to K8 No REPAIR the circuit. - Measure:
- K8 CHECK THE BLOWER MOTOR SPEED CONTROL PWM (PULSE WIDTH MODULATION) CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead Refer to C297A-3 Ground
Is any voltage present?
Yes REPAIR the circuit. No GO to K9 - K9 CHECK THE BLOWER MOTOR SPEED CONTROL PWM (PULSE WIDTH MODULATION) CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure:
Positive Lead Measurement / Action Negative Lead Refer to C297A-3 Ground
Is the resistance greater than 10, 000 ohms?
Yes GO to K10 No REPAIR the circuit. - K10 CHECK THE BLOWER MOTOR SPEED CONTROL PWM (PULSE WIDTH MODULATION) CIRCUIT FOR AN OPEN
Is the resistance less than 3 ohms?
Yes GO to K11 No REPAIR the circuit. - K11 CHECK THE OUTPUTS TO THE BLOWER MOTOR
- Disconnect Blower motor C2004.
- Connect Blower motor relay.
- Connect Blower motor speed control C297A.
- Connect HVAC control module C294A.
- Ignition ON.
- Select PANEL on the HVAC controls.
- Select the highest blower motor setting.
Is the voltage greater than 11 volts?
Yes INSTALL a new blower motor. REFER to: Blower Motor . No GO to K12 - K12 CHECK THE CIRCUITS TO THE BLOWER MOTOR FOR AN OPEN
- Ignition OFF.
- Disconnect Blower motor speed control C297B.
- Measure:
Positive Lead Measurement / Action Negative Lead Refer to C297B-1 Refer to C2004-1 Refer to C297B-2 Refer to C2004-2
Are the resistances less than 3 ohms?
Yes GO to K13 No REPAIR the circuit in question. - K13 CHECK THE BLOWER MOTOR CIRCUITS FOR A SHORT TOGETHER
Is the resistance greater than 10, 000 ohms?
Yes INSTALL a new blower motor speed control. REFER to: Blower Motor Speed Control . TEST the system for normal operation. If the concern is still present, GO to K14 No REPAIR the circuits. - K14 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION
- Ignition OFF.
- Disconnect and inspect all HVAC control module electrical connectors (if not previously disconnected).
- Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- Connect all HVAC control module electrical connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new HVAC control module. REFER to: Heating, Ventilation and Air Conditioning (HVAC) Control Module . No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.