Pinpoint Test C: DTC B2266 or B2267
Climate Control System
Pinpoint Tests
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, the driver side (LH) and passenger side (RH) temperature blend door actuator motors are supplied voltage or ground on circuit 245 (BN/LG) (LH) or 1125 (BN) (RH), depending on desired actuator rotation, by the HVAC module. The HVAC module then supplies the appropriate voltage or ground to the other side of the actuator motor on circuit 246 (VT) (LH) or 1124 (WH) (RH).
The driver side (LH) and passenger side (RH) temperature blend door actuator feedback resistors are supplied a ground from the HVAC module by circuit 438 (RD/WH) and a 5-volt reference voltage on circuit 436 (RD/LG). The HVAC module reads the voltage on circuit 437 (RD/WH) (LH) or 1122 (RD) (RH) to determine the actuator position by the position of the actuator feedback resistor wiper arm.
- 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 C2.
If diagnosing DTC B2267, GO to C3.
No
CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, REPAIR circuits 436 (RD/LG) and 438 (RD/WH) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Blend Door Actuator
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C2 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
If the low-side resistance only is greater than 5,500 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, REPAIR circuit 438 (RD/WH) for an open. CLEAR the DTCs. REPEAT the self-test. Blend Door Actuator
TEST the system for normal operation.
If the low-side resistance only is less than 250 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, 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. Blend Door Actuator
If the high-side resistance only is greater than 5,500 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, REPAIR circuit 436 (RD/LG) for an open. CLEAR the DTCs. REPEAT the self-test. Blend Door Actuator
TEST the system for normal operation.
If thehigh-side resistance only is less than 250 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, 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. Blend Door Actuator
If thehigh-side and low-side resistance is greater than 5,500 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, REPAIR circuit 437 (YE/LG) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Blend Door Actuator
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C3 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 C4.
No
If the low-side resistance only is greater than 5,500 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, REPAIR circuit 438 (RD/WH) for an open. CLEAR the DTCs. REPEAT the self-test. Blend Door Actuator
TEST the system for normal operation.
If the low-side resistance only is less than 250 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, 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. Blend Door Actuator
If the high-side resistance only is greater than 5,500 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, REPAIR circuit 436 (RD/LG) for an open. CLEAR the DTCs. REPEAT the self-test. Blend Door Actuator
TEST the system for normal operation.
If thehigh-side resistance only is less than 250 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, 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. Blend Door Actuator
If thehigh-side and low-side resistance is greater than 5,500 ohms, CARRY OUT the Blend Door Actuator Component Test. If the actuator tests OK, REPAIR circuit 1122 (RD) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Blend Door Actuator
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C4 CHECK CIRCUITS 436 (RD/LG), 437 (YE/LG) AND 1122 (RD) FOR A SHORT TO GROUND
- 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
GO to C5.
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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C5 CHECK CIRCUITS 438 (RD/WH), 437 (YE/LG) AND 1122 (RD) FOR A SHORT TO VOLTAGE
- 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
If diagnosing DTC B1263, GO to C6.
If diagnosing DTC B1264, GO to C7.
No
REPAIR circuit(s) for a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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C6 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.
- 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. If no condition is found, GO to C9.
No
GO to C8.
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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.
- 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. If no condition is found, GO to C9.
No
GO to C8.
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C8 CHECK THE ACTUATOR MOTOR DRIVE CIRCUITS FOR AN OPEN
NOTE: Due to limited connector accessibility, before carrying out this test step, visually inspect the wiring between the HVAC module and actuator for opens or shorts. If no damage is visually 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.
DTC B2266
- NOTE: For DTC B2266 only.
- 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.
DTC B2266
- NOTE: For DTC B2266 only.
- 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.
DTC B2267
- NOTE: For DTC B2267 only.
- 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.
DTC B2267
- NOTE: For DTC B2267 only.
- 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.
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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C9 CHECK HVAC MODULE CONNECTION
- Carry out the HVAC Module Cold Boot Process. HVAC Module Cold Boot Process
- Carry out the HVAC Module On-Demand Self Test. HVAC Module Self-Test
- Operate the system.
- Does the concern return?
Yes
INSTALL a new HVAC module. 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. REPEAT the self-test. TEST the system for normal operation.
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