Pinpoint Test K: Incorrect/Erratic Direction of Airflow From Outlets

Climate Control System

Pinpoint Test K: Incorrect/Erratic Direction of Airflow From Outlets

Refer to Wiring Diagrams Set 54, Manual Climate Control System for schematic and connector information. Electrical Diagrams

Refer to Wiring Diagrams Set 55, Automatic Climate Control System for schematic and connector information. Electrical Diagrams

Normal Operation

Under normal operation, to rotate the defrost/panel/floor mode door actuator, the HVAC module supplies voltage and ground to the defrost/panel/floor mode door actuator motor through the actuator motor circuits. To reverse the defrost/panel/floor mode door actuator rotation, the HVAC module reverses the voltage and ground circuits.

The defrost/panel/floor mode door actuator feedback resistor is supplied a 5-volt reference voltage and ground from the HVAC module. The HVAC module measures the resistance on the defrost/panel/floor mode door actuator feedback circuit to determine the defrost/panel/floor mode door actuator position by the position of the actuator feedback resistor wiper arm.

During an actuator calibration cycle, the HVAC module drives the defrost/panel/floor mode door until the door reaches both internal stops in the HVAC case. If the defrost/panel/floor mode door is temporarily obstructed or binding during a calibration cycle, the HVAC module may interpret this as the actual end of travel for the door. When this condition occurs and the HVAC module commands the actuator to its end of travel, the airflow may not be from the expected outlets.





This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Defrost/panel/floor mode door actuator

- HVAC module

- Stuck or bound linkage or door

PINPOINT TEST K : INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLETS

K1 CHECK THE HVAC MODULE FOR DTCs

- Ignition ON.

- Check the HVAC module for DTCs.

Are any DTCs present?

Yes

For DTC B1086:00, INSPECT for binding/damaged linkage or door. REPAIR as necessary. If no condition is found, GO to K4.

For DTC B1086:11, GO to K2.

For DTC B1086:12, GO to K3.

For DTC B11E7:11, GO to K6.

For DTC B11E7:15, GO to K8.

No
INSPECT for broken linkage or door. REPAIR as necessary. If no condition is found, GO to K13.

K2 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR A SHORT TO GROUND

- Ignition OFF.

- Disconnect: HVAC Module C228A.

- Disconnect: HVAC Module C228B.

- Measure the resistance between ground and:
- HVAC module C228A-20, circuit CH228 (YE/GY), harness side.

- HVAC module C228A-21, circuit CH229 (WH/BU), harness side.






Are the resistances greater than 10,000 ohms?

Yes
GO to K5.

No
REPAIR circuit CH228 (YE/GY) or CH229 (WH/BU) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K3 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: HVAC Module C228A.

- Disconnect: HVAC Module C228B.

- Ignition ON.

- Measure the voltage between ground and:
- HVAC module C228A-20, circuit CH228 (YE/GY), harness side.

- HVAC module C228A-21, circuit CH229 (WH/BU), harness side.






Is any voltage present?

Yes
REPAIR circuit CH228 (YE/GY) or CH229 (WH/BU) for a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
GO to K5.

K4 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR AN OPEN

NOTE: Access to the connector in the following step is difficult. Before performing this step, visually inspect the actuator and its harness for obvious damage. If no damage is evident, proceed with the test.

- Ignition OFF.

- Disconnect: HVAC Module C228A.

- Disconnect: HVAC Module C228B.

- Disconnect: Defrost/Panel/Floor Mode Door Actuator C2278.

- Measure the resistance between HVAC module C228A-20, circuit CH228 (YE/GY), harness side and defrost/panel/floor mode door actuator C2278-6, circuit CH228 (YE/GY), harness side.





- Measure the resistance between HVAC module C228A-21, circuit CH229 (WH/BU), harness side and defrost/panel/floor mode door actuator C2278-1, circuit CH229 (WH/BU), harness side.





Are the resistances less than 5 ohms?

Yes
GO to K13.

No
REPAIR circuit CH228 (YE/GY) or CH229 (WH/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K5 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR A SHORT TOGETHER

- Ignition OFF.

- Measure the resistance between HVAC module C228A-20, circuit CH228 (YE/GY), harness side and HVAC module C228A-21, circuit CH229 (WH/BU), harness side.





Is the resistance greater than 10,000 ohms?

Yes
GO to K13.

No
REPAIR circuits CH228 (YE/GY) and CH229 (WH/BU) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K6 CHECK CIRCUIT VH436 (YE/VT) FOR A SHORT TO GROUND

- Ignition OFF.

- Disconnect: HVAC Module C228A.

- Disconnect: HVAC Module C228B.

- Measure the resistance between ground and HVAC module C228A-6, circuit VH436 (YE/VT), harness side.





Are the resistances greater than 10,000 ohms?

Yes
GO to K7.

No
REPAIR circuit VH436 (YE/VT) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K7 CHECK CIRCUIT RH111 (GY/BU) FOR A SHORT TO CIRCUIT VH436 (YE/VT)

NOTE: Access to the connector in the following step is difficult. Before performing this step, visually inspect the actuator and its harness for obvious damage. If no damage is evident, proceed with the test.

- Disconnect: Defrost/Panel/Floor Mode Door Actuator C2278.

- Measure the resistance between HVAC module C228A-4, circuit RH111 (GY/BU), harness side and HVAC module C228A-6, circuit VH436 (YE/VT), harness side.





Is the resistance greater than 10,000 ohms?

Yes
GO to K13.

No
REPAIR circuits RH111 (GY/BU) and VH436 (YE/VT) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K8 CHECK CIRCUIT VH436 (YE/VT) FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: HVAC Module C228A.

- Disconnect: HVAC Module C228B.

- Ignition ON.

- Measure the voltage between ground and HVAC module C228A-6, circuit VH436 (YE/VT), harness side.





Is any voltage present?

Yes
REPAIR circuit VH436 (YE/VT) for a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
GO to K9.

K9 CHECK CIRCUIT LH111 (BN/WH) FOR A SHORT TO CIRCUIT VH436 (YE/VT)

NOTE: Access to the connector in the following step is difficult. Before performing this step, visually inspect the actuator and its harness for obvious damage. If no damage is evident, proceed with the test.

- Ignition OFF.

- Disconnect: Defrost/Panel/Floor Mode Door Actuator C2278.

- Measure the resistance between HVAC module C228A-3, circuit LH111 (BN/WH), harness side and HVAC module C228A-6, circuit VH436 (YE/VT), harness side.





Is the resistance greater than 10,000 ohms?

Yes
GO to K10.

No
REPAIR circuits LH111 (BN/WH) and VH436 (YE/VT) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K10 CHECK CIRCUIT VH436 (YE/VT) FOR AN OPEN

- Measure the resistance between HVAC module C228A-6, circuit VH436 (YE/VT), harness side and defrost/panel/floor mode door actuator C2278-4, circuit VH436 (YE/VT), harness side.





Is the resistance less than 5 ohms?

Yes
GO to K11.

No
REPAIR circuit VH436 (YE/VT) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K11 CHECK THE ACTUATOR RETURN CIRCUIT RH111 (GY/BU) FOR AN OPEN

- Measure the resistance between HVAC module C228A-4, circuit RH111 (GY/BU), harness side and defrost/panel/floor mode door actuator C2278-2, circuit RH111 (GY/BU), harness side.





Is the resistance less than 5 ohms?

Yes
GO to K12.

No
REPAIR circuit RH111 (GY/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K12 CHECK CIRCUIT LH111 (BN/WH) FOR AN OPEN

- Measure the resistance between HVAC module C228A-3, circuit LH111 (BN/WH), harness side and defrost/panel/floor mode door actuator C2278-3, circuit LH111 (BN/WH), harness side.





Is the resistance less than 5 ohms?

Yes
GO to K13.

No
REPAIR circuit LH111 (BN/WH) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

K13 CHECK THE ACTUATOR CONNECTION

- Inspect the connector for:
- corrosion.
- pushed-out terminals.
- damaged terminals.


- Connect and correctly seat the actuator connector.

- Clear the DTCs.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
CARRY OUT the Defrost/Panel/Floor Mode Door Actuator component test. If the actuator tests OK, GO to K14. Component Tests and General Diagnostics

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

K14 MODULE ACTUATOR POSITION CALIBRATION

NOTE: The purpose of the module actuator position calibration is to allow the HVAC module to reinitialize and calibrate the actuator stop points. To carry out the calibration, follow the steps below.

- Ignition OFF.

- Inspect the module connectors for:
- corrosion.
- pushed-out terminals.
- damaged terminals.


- Connect and correctly seat all the HVAC module connectors.

- Ignition ON.

- Clear the DTCs.

- Select any position except OFF.

- NOTE: The HVAC module will now initialize and calibrate the actuators. Calibration of the actuators will take approximately 30 seconds.
Operate the system and verify the concern is still present.


Is the concern still present?

Yes
INSTALL a new HVAC module. TEST the system for normal operation.

No
The system is now operating correctly at this time. The concern may have been caused by a foreign object in the HVAC case or temporary binding that restricted actuator door travel. CHECK any actuator external linkage. If condition recurs, INSPECT actuator linkage and door for binding and CHECK HVAC case for foreign objects.