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Pinpoint Test C: DTC B2266 Or B2267




Climate Control System

Pinpoint Test C: DTC B2266 or B2267

Refer to Wiring Diagram Set 55, Automatic 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 resistors are supplied a ground from the HVAC module by the temperature blend door actuator return circuits 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 may not be the expected temperature.

- DTC B2266 (Left Side Blend Door Circuit Failure) - The module senses no change in actuator feedback voltage when the actuator motor has been energized.
- DTC B2267 (Right Side Blend Door Circuit Failure) - The module senses no change in actuator feedback voltage when the actuator motor has been energized.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Driver side (LH) or passenger side (RH) temperature blend door actuator
- HVAC module
- Stuck or bound linkage or door


PINPOINT TEST C: DTC B2266 OR B2267

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C1 CHECK THE FEEDBACK POTENTIOMETER TOTAL RESISTANCE


- Disconnect: HVAC Module C228A.
- Disconnect: HVAC Module C228B.
- Measure the resistance between HVAC module C228B-8, circuit 436 (RD/LG), harness side and HVAC module C228A-20, circuit 438 (RD/WH), harness side.




- Is the resistance greater than 500 ohms?

Yes
If diagnosing DTC B2266, GO to C3.

If diagnosing DTC B2267, GO to C4.

No
GO to C2.

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C2 CHECK POTENTIOMETER FEEDBACK 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.

- Measure the resistance between HVAC module C228B-8, circuit 436 (RD/LG), harness side and HVAC module C228A-20, circuit 438 (RD/WH), harness side.




- While measuring the resistance above, disconnect the following components one at a time, in order. Stop disconnecting components if the measured resistance rises above 500 ohms.

- Air inlet door actuator C289
- LH blend door actuator C2092
- RH blend door actuator C2092
- Did the resistance rise above 500 ohms?

Yes
INSTALL a new actuator (the last one to be disconnected). CONNECT the actuator electrical connectors before the HVAC module connectors. 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.

No
Visually INSPECT the harness between the actuators and the HVAC module for obvious damage. REPAIR as necessary. If no damage is evident, INSTALL a new floor door actuator and panel/defrost door actuator. If a new actuator is installed, CONNECT the actuator electrical connectors before the HVAC module connectors. 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.

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C3 CHECK POTENTIOMETER LOW- AND HIGH-SIDE RESISTANCE


- Measure the low-side resistance between HVAC module C228B-4, circuit 437 (YE/LG), harness side and HVAC module C228A-20, circuit 438 (RD/WH), harness side.




- Measure the high-side resistance between HVAC module C228B-4, circuit 437 (YE/LG), harness side and HVAC module C228B-8, circuit 436 (RD/LG), harness side.




- Is the resistance between 250 and 5,500 ohms?

Yes
GO to C4.

No
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 and: Component Tests and General Diagnostics

If the low-side resistance only is greater than 5,500 ohms, REPAIR circuit 438 (RD/WH) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If the low-side resistance only is less than 250 ohms, REPAIR circuits 437 (YE/LG) and 438 (RD/WH) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If the high-side resistance only is greater than 5,500 ohms, REPAIR circuit 436 (RD/LG) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If thehigh-side resistance only is less than 250 ohms, REPAIR circuits 437 (YE/LG) and 436 (RD/LG) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If both thehigh-side and low-side resistance is greater than 5,500 ohms, REPAIR circuit 437 (YE/LG) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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C4 CHECK POTENTIOMETER LOW- AND HIGH-SIDE RESISTANCE


- Measure the low-side resistance between HVAC module C228B-5, circuit 1122 (RD), harness side and HVAC module C228A-20, circuit 438 (RD/WH), harness side.




- Measure the high-side resistance between HVAC module C228B-5, circuit 1122 (RD), harness side and HVAC module C228B-8, circuit 436 (RD/LG), harness side.




- Is the resistance between 250 and 5,500 ohms?

Yes
GO to C5.

No
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 and: Component Tests and General Diagnostics

If the low-side resistance only is greater than 5,500 ohms, REPAIR circuit 438 (RD/WH) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If the low-side resistance only is less than 250 ohms, REPAIR circuits 1122 (RD) and 438 (RD/WH) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If the high-side resistance only is greater than 5,500 ohms, REPAIR circuit 436 (RD/LG) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If thehigh-side resistance only is less than 250 ohms, REPAIR circuits 1122 (RD) and 436 (RD/LG) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If both thehigh-side and low-side resistance is greater than 5,500 ohms, REPAIR circuit 1122 (RD) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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C5 CHECK CIRCUITS 438 (RD/WH), 437 (YE/LG) AND 1122 (RD) FOR A SHORT TO VOLTAGE


- Ignition ON.
- Measure the voltage between ground and the following:
- HVAC module C228A-20, circuit 438 (RD/WH), harness side.
- For DTC B2266, HVAC module C228B-4, circuit 437 (YE/LG), harness side.
- For DTC B2267, HVAC module C228B-5, circuit 1122 (RD), harness side.




- Is any voltage present?

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

No
GO to C6.

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C6 CHECK CIRCUITS 436 (RD/LG), 437 (YE/LG) AND 1122 (RD) FOR A SHORT TO GROUND


- Ignition OFF.
- Measure the resistance between ground and the following:
- HVAC module C228B-8, circuit 436 (RD/LG), harness side.
- For DTC B2266, HVAC module C228B-4, circuit 437 (YE/LG), harness side.
- For DTC B2267, HVAC module C228B-5, circuit 1122 (RD), harness side.




- Is the resistance greater than 10,000 ohms?

Yes
If diagnosing DTC B2266, GO to C7.

If diagnosing DTC B2267, GO to C8.

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

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C7 CHECK THE BLEND DOOR ACTUATOR OPERATION


NOTE: If a jumper fuse opens while carrying out this test step, repair the circuit(s) for a short.

- Ignition ON.
- With the fused jumper connections made as directed below, measure the resistance between HVAC module C228B-4, circuit 437 (YE/LG), harness side and HVAC module C228A-20, circuit 438 (RD/WH), harness side.




- Connect a fused jumper wire between:
- HVAC module C228A-11, circuit 1124 (WH), harness side and HVAC module C228B-11, circuit 1566 (RD/YE), harness side.
- HVAC module C228A-12, circuit 1125 (BN), harness side and HVAC module C228A-2, circuit 57 (BK), harness side.




- Remove the fused jumpers.
- Connect a fused jumper wire between:
- HVAC module C228A-13, circuit 246 (VT), harness side and HVAC module C228B-11, circuit 1566 (RD/YE), harness side.
- HVAC module C228A-26, circuit 245 (BN/LG), harness side and HVAC module C228A-2, circuit 57 (BK), harness side.




- Does the resistance smoothly increase and/or decrease when the jumpers are connected?

Yes
INSPECT for broken door and linkage. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. If no condition is found, GO to C11.

No
GO to C9.

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C8 CHECK THE BLEND DOOR ACTUATOR OPERATION


NOTE: If a jumper fuse opens while carrying out this test step, repair the circuit(s) for a short.

- Ignition ON.
- With the fused jumper connections made as directed below, measure the resistance between HVAC module C228B-5, circuit 1122 (RD), harness side and HVAC module C228A-20, circuit 438 (RD/WH), harness side.




- Connect a fused jumper wire between:
- HVAC module C228A-12, circuit 1125 (BN), harness side and HVAC module C228B-11, circuit 1566 (RD/YE), harness side.
- HVAC module C228A-11, circuit 1124 (WH), harness side and HVAC module C228A-2, circuit 57 (BK), harness side.




- Remove the fused jumpers.
- Connect a fused jumper wire between:
- HVAC module C228A-26, circuit 245 (BN/LG), harness side and HVAC module C228B-11, circuit 1566 (RD/YE), harness side.
- HVAC module C228A-13, circuit 246 (VT), harness side and HVAC module C228A-2, circuit 57 (BK), harness side.




- Does the resistance smoothly increase and/or decrease when the jumpers are connected?

Yes
INSPECT for broken door and linkage. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. If no condition is found, GO to C11.

No
GO to C9.

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C9 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: For DTC B2266, LH Temperature Blend Door Actuator C2091.
- Disconnect: For DTC B2267, RH Temperature Passenger Blend Door Actuator C2092.

For DTC B2266




- For DTC B2266, measure the resistance between HVAC module C228A-26, circuit 245 (BN/LG), harness side and the LH temperature blend door actuator C2091-6, circuit 245 (BN/LG), harness side.

For DTC B2266




- For DTC B2266, measure the resistance between HVAC module C228A-13, circuit 246 (VT), harness side and the LH temperature blend door actuator C2091-1, circuit 246 (VT), harness side.

For DTC B2267




- For DTC B2267, measure the resistance between HVAC module C228A-12, circuit 1125 (BN), harness side and the RH temperature blend door actuator C2092-6, circuit 1125 (BN), harness side.

For DTC B2267




- For DTC B2267, measure the resistance between HVAC module C228A-11, circuit 1124 (WH), harness side and the RH temperature blend door actuator C2092-1, circuit 1124 (WH), harness side.
- Is the resistance less than 5 ohms?

Yes
INSPECT for binding or broken linkage. REPAIR as necessary. If no condition is found, INSTALL a new door actuator. TEST the system for normal operation. If no condition is found, GO to C10.

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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C10 CHECK THE ACTUATOR CONNECTION


- Disconnect the actuator connector.
- Check 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
INSTALL a new blend door actuator. If a new actuator is installed, CONNECT the actuator electrical connectors before the HVAC module connectors. 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.

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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C11 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. REFER to Climate Control Service and Repair. 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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