Pinpoint Test E: The Air Inlet Door Is Inoperative
Climate Control System
Pinpoint Tests
Pinpoint Test E: The Air Inlet Door is Inoperative
Refer to Wiring Diagrams Set 54, Climate Control System for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, the air inlet mode door actuator is supplied voltage or ground on circuit CH208 (GN/OG), 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 CH207 (BU/GY).
- DTC B12A8 Recirc Door Actuator, Drive Circuit(s) Open or Shorted to Ground - The module senses no voltage on the door actuator drive circuit(s), indicating an open circuit or a short directly to ground.
- DTC B12A9 Recirc Door Actuator, Drive Circuit(s) Shorted to Battery Voltage - The module senses voltage on the door actuator drive circuits, indicating a short directly to voltage.
- DTC B12AA Recirc Door Actuator, Slow or Door Obstructed - 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
- Air inlet mode door actuator
- HVAC module
- Stuck or damaged linkage or door
PINPOINT TEST E: THE AIR INLET DOOR IS INOPERATIVE
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E1 CHECK THE HVAC MODULE FOR DTCs
- Ignition ON.
- Check the HVAC module for DTCs.
- Is DTC B12A8 or B12A9 present?
Yes
For DTC B12A9, GO to E2.
For DTC B12A8, GO to E3.
No
INSPECT for broken/binding actuator drive shaft or door. REPAIR as necessary. If no condition is found, GO to E6.
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E2 CHECK CIRCUITS CH207 (BU/GY) AND CH208 (GN/OG) FOR A SHORT TO POWER
- Ignition OFF.
- Disconnect: HVAC Module C2357a.
- Disconnect: Air Inlet Mode Door Actuator C2261.
- Ignition ON.
- Measure the voltage between ground and:
- HVAC module C2357a-16, circuit CH208 (GN/OG), harness side.
- HVAC module C2357a-15, circuit CH207 (BU/GY), harness side.
- Is any voltage present?
Yes
REPAIR circuit CH207 (BU/GY) or CH208 (GN/OG) for a short to power. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to E5.
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E3 CHECK CIRCUITS CH207 (BU/GY) AND CH208 (GN/OG) FOR AN OPEN
- Ignition OFF.
- Disconnect: HVAC Module C2357a.
- Disconnect: Air Inlet Mode Door Actuator C2261.
- Measure the resistance between HVAC module C2357a-16, circuit CH208 (GN/OG), harness side and air inlet mode door actuator C2261-5, circuit CH208 (GN/OG), harness side.
- Measure the resistance between HVAC module C2357a-15, circuit CH207 (BU/GY), harness side and air inlet mode door actuator C2261-6, circuit CH207 (BU/GY), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to E4.
No
REPAIR circuit CH207 (BU/GY) or CH208 (GN/OG) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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E4 CHECK CIRCUITS CH207 (BU/GY) AND CH208 (GN/OG) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: HVAC Module C2357a.
- Disconnect: Air Inlet Mode Door Actuator C2261.
- Measure the resistance between ground and:
- HVAC module C2357a-16, circuit CH208 (GN/OG), harness side.
- HVAC module C2357a-15, circuit CH207 (BU/GY), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to E5.
No
REPAIR circuit CH207 (BU/GY) or CH208 (GN/OG) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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E5 CHECK CIRCUITS CH207 (BU/GY) AND CH208 (GN/OG) FOR A SHORT TOGETHER
- Ignition OFF.
- Measure the resistance between HVAC module C2357a-15, circuit CH207 (BU/GY), harness side and HVAC module C2357a-16, circuit CH208 (GN/OG), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to E6.
No
REPAIR circuits CH208 (GN/OG) and CH207 (BU/GY) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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E6 CHECK THE ACTUATOR CONNECTION
- 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. HVAC Module Cold Boot Process
- Operate the system.
- Does the concern return?
Yes
CARRY OUT the air inlet mode door actuator component test. If the actuator tests OK, GO to E7. Air Inlet Mode Door Actuator
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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E7 CHECK THE MODULE CONNECTION
- Carry out the HVAC Module Cold Boot Process. HVAC Module Cold Boot Process
- 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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