Pinpoint Test K: Temperature Control is Inoperative/Does Not Operate Correctly
Climate Control System
Pinpoint Tests
Pinpoint Test K: Temperature Control is Inoperative/Does Not Operate Correctly
Refer to Wiring Diagram Set 54, Manual Climate Control System for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, to rotate the temperature blend door actuator, the HVAC module supplies voltage and ground to the temperature blend door actuators through the door actuator motor circuits. To reverse the temperature blend door actuator rotation, the HVAC module reverses the voltage and ground circuits.
The temperature blend door actuator feedback resistor is supplied a ground from the HVAC module and a 5-volt reference voltage on the temperature blend door actuator reference circuits. The HVAC module reads the voltage on the temperature blend door actuator feedback circuits to determine the temperature blend door actuator position by the position of the actuator feedback resistor wiper arm.
During an actuator calibration cycle, the HVAC module drives the temperature blend door until the door reaches both internal stops in the HVAC case. If the temperature blend 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 temperature may not be as warm or cold as expected.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Blend door actuator
- HVAC module
- Stuck or damaged linkage or door
PINPOINT TEST K: TEMPERATURE CONTROL IS INOPERATIVE/DOES NOT OPERATE CORRECTLY
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K1 CHECK THE HVAC MODULE FOR DTCs
- Ignition ON.
- Check the HVAC module for DTCs.
- Are any DTCs present?
Yes
For DTC B12B7, INSPECT for binding/damaged linkage or door. REPAIR as necessary. If no condition is found, INSTALL a new door actuator. REFER to Climate Control Service and Repair. If a new actuator is installed, CONNECT the actuator electrical connector before the HVAC module connector(s). This will allow the new actuator to be calibrated when the HVAC module is reconnected. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
For DTC B12B3, GO to K2.
For DTC B297A, GO to K3.
For DTC B297B, GO to K4.
For DTC B12B5, GO to K6.
For DTC B12B6, GO to K10.
No
CHECK that the A/C system pressure is above 290 kPa (42 psi). If the pressure is below 290 kPa (42 psi), REFER to Fluorescent Dye Leak Detection Fluorescent Dye Leak Detection. INSPECT for broken/binding actuator drive shaft or door. If no condition is found, GO to K13.
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K2 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR A SHORT TO POWER
- Ignition OFF.
- Disconnect: HVAC Module C2357A.
- Ignition ON.
- Measure the voltage between ground and:
- HVAC module C2357A-21, circuit CH233 (VT/BN), harness side.
- HVAC module C2357A-22, circuit CH234 (YE/GN), harness side.
- Are any voltages present?
Yes
REPAIR the circuit(s) for a short to power. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to K5.
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K3 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 C2357A.
- Disconnect: Blend Door Actuator C289.
- Measure the resistance between HVAC module C2357A-21, circuit CH233 (VT/BN), harness side and LH blend door actuator C289-6, circuit CH233 (VT/BN), harness side.
- Measure the resistance between HVAC module C2357A-22, circuit CH234 (YE/GN), harness side and LH blend door actuator C289-5, circuit CH234 (YE/GN), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to K13.
No
REPAIR the circuit(s) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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K4 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: HVAC Module C2357A.
- Measure the resistance between ground and:
- HVAC module C2357A-21, circuit CH233 (VT/BN), harness side.
- HVAC module C2357A-22, circuit CH234 (YE/GN), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
GO to K5.
No
REPAIR the circuit(s) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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K5 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR A SHORT TOGETHER
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: Blend Door Actuator C289.
- Measure the resistance between HVAC module C2357A-22, circuit CH234 (YE/GN), harness side and HVAC module C2357A-21, circuit CH233 (VT/BN), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to K13.
No
REPAIR circuit(s) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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K6 CHECK CIRCUIT VH439 (GY/VT) 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 C2357A.
- Disconnect: Blend Door Actuator C289.
- Measure the resistance between HVAC module C2357A-7, circuit VH439 (GY/VT), harness side and blend door actuator C289-2, circuit VH439 (GY/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to K7.
No
REPAIR circuit VH439 (GY/VT) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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K7 CHECK CIRCUIT VH439 (GY/VT) FOR A SHORT TO POWER
- Ignition ON.
- Measure the voltage between ground and HVAC module C2357A-7, circuit VH439 (GY/VT), harness side.
- Is any voltage present?
Yes
REPAIR circuit VH439 (GY/VT) for a short to power. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to K8.
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K8 CHECK CIRCUITS LH111 (BN/WH) AND VH439 (GY/VT) FOR A SHORT TOGETHER
- Ignition OFF.
- Measure the resistance between HVAC module C2357A-11, circuit LH111 (BN/WH) and HVAC module C2357A-7, circuit VH439 (GY/VT), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to K9.
No
REPAIR circuits LH111 (BN/WH) and VH439 (GY/VT) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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K9 CHECK THE ACTUATOR RETURN CIRCUIT RH111 (GY/BU) FOR AN OPEN
- Measure the resistance between HVAC module C2357A-10, circuit RH111 (GY/BU) and blend door actuator C289-1, circuit RH111 (GY/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to K13.
No
REPAIR circuit RH111 (GY/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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K10 CHECK CIRCUIT VH439 (GY/VT) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: HVAC Module C2357A.
- Measure the resistance between ground and HVAC module C2357A-7, circuit VH439 (GY/VT), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to K11.
No
REPAIR circuit VH439 (GY/VT) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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K11 CHECK CIRCUITS RH111 (GY/BU) AND VH439 (GY/VT) FOR A SHORT TOGETHER
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: Blend Door Actuator C289.
- Measure the resistance between HVAC module C2357A-10, circuit RH111 (GY/BU) and HVAC module C2357A-7, circuit VH439 (GY/VT), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to K12.
No
REPAIR circuits RH111 (GY/BU) and VH439 (GY/VT) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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K12 CHECK CIRCUIT LH111 (BN/WH) FOR AN OPEN
- Measure the resistance between HVAC module C2357A-11, circuit LH111 (BN/WH) and blend door actuator C289-3, 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.
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K13 CHECK THE ACTUATOR CONNECTION
- Clear the DTCs.
- Disconnect the actuator connector.
- Check for:
- corrosion.
- pushed-out connectors.
- incorrectly seated connector.
- Connect and correctly seat the actuator connector.
- Carry out the HVAC Module Cold Boot Process.
- Operate the system.
- Does the concern return?
Yes
CARRY OUT the Blend Door Actuator component test. If a new actuator is installed, CONNECT the actuator electrical connector before the HVAC module connector(s). This will allow the new actuator to be calibrated when the HVAC module is reconnected. If the actuator tests OK, GO to K14. Climate Control System
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. TEST the system for normal operation.
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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.
- Disconnect and inspect the HVAC 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.
- Enter the following diagnostic mode on the scan tool: Self Test - HVAC Module.
- Is the concern still present or the DTCs return?
Yes
INSTALL a new HVAC module. REFER to Climate Control Heating Ventilation Air Conditioning (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.
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