Pinpoint Test C: DTC B1239 - Airflow Blend Door Driver Circuit Failure

Climate Control System

Pinpoint Tests

Pinpoint Test C: DTC B1239 - Airflow Blend Door Driver Circuit Failure

Refer to Wiring Diagram Set 55 (Escape/Mariner, Escape Hybrid/Mariner Hybrid), Automatic Climate Control System for schematic and connector information. Diagrams By Number

Normal Operation

When the outside ambient air temperature is cool enough to provide adequate high-voltage battery cooling, the Traction Battery Control Module (TBCM) positions the auxiliary air inlet door actuator in the OPEN position. If the outside ambient air temperature is too warm to provide adequate High Voltage Traction Battery (HVTB) cooling, the TBCM positions the auxiliary air inlet door actuator in the CLOSED position and requests A/C cooling. The TBCM sends and receives signals to the auxiliary air inlet door actuator on circuits RYB10 (GY/BU)/1128 (GY/LB), CYB10 (BU/WH)/1129 (BN/WH) and VYB11 (GN/VT)/1130 (PK/LG), indicating the position of the auxiliary air inlet door. The TBCM controls the movement of the door by controlling power and ground to the auxiliary air inlet door actuator through circuits CYB13 (BU/GN)/698 (RD) and CYB12 (YE/GN)/699 (OG).

- DTC B1239 Airflow Blend Door Driver Circuit Failure - The module senses an open/short on any actuator circuit or 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
- Auxiliary air inlet mode door actuator
- Broken or binding air inlet door or linkage
- TBCM

PINPOINT TEST C: DTC B1239 - AIRFLOW BLEND DOOR DRIVER CIRCUIT FAILURE

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C1 CHECK ACTUATOR CIRCUITS FOR A SHORT TO VOLTAGE

- Ignition OFF.
- Disconnect: TBCM C4227a.
- Ignition ON.
- Measure the voltage between ground and:
- TBCM C4227a-34, circuit CYB13 (BU/GN)/698 (RD), harness side.
- TBCM C4227a-26, circuit CYB12 (YE/GN)/699 (OG), harness side.
- TBCM C4227a-24, circuit RYB10 (GY/BU)/1128 (GY/LB), harness side.
- TBCM C4227a-17, circuit CYB10 (BU/WH)/1129 (BN/WH), harness side.
- TBCM C4227a-20, circuit VYB11 (GN/VT)/1130 (PK/LG), 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 C2.

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C2 CHECK ACTUATOR CIRCUITS FOR A SHORT TO GROUND

- Ignition OFF.
- Measure the resistance between ground and:
- TBCM C4227a-34, circuit CYB13 (BU/GN)/698 (RD), harness side.
- TBCM C4227a-26, circuit CYB12 (YE/GN)/699 (OG), harness side.
- TBCM C4227a-24, circuit RYB10 (GY/BU)/1128 (GY/LB), harness side.
- TBCM C4227a-17, circuit CYB10 (BU/WH)/1129 (BN/WH), harness side.
- TBCM C4227a-20, circuit VYB11 (GN/VT)/1130 (PK/LG), harness side.

- Is the resistance greater than 10,000 ohms?

Yes
GO to C3.

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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C3 CHECK THE ACTUATOR TOTAL RESISTANCE

- Measure the resistance between TBCM C4227a-17, circuit CYB10 (BU/WH)/1129 (BN/WH), harness side and TBCM C4227a-24, circuit RYB10 (GY/BU)/1128 (GY/LB), harness side.

- Is the resistance 3,500-7,500 ohms?

Yes
GO to C4.

No
If the resistance is below 5 ohms, REPAIR circuits RYB10 (GY/BU)/1128 (GY/LB) and CYB10 (BU/WH)/1129 (BN/WH) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

All other values, GO to C7.

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C4 CHECK THE ACTUATOR HIGH-SIDE RESISTANCE

- Measure the resistance between TBCM C4227a-17, circuit CYB10 (BU/WH)/1129 (BN/WH), harness side and TBCM C4227a-20, circuit VYB11 (GN/VT)/1130 (PK/LG), harness side.

- Is the resistance 1,500-5,500 ohms?

Yes
GO to C5.

No
If the resistance is below 5 ohms, REPAIR circuits CYB10 (BU/WH)/1129 (BN/WH) and VYB11 (GN/VT)/1130 (PK/LG) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

All other values, GO to C7.

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C5 CHECK THE ACTUATOR MOTOR RESISTANCE

- Measure the resistance between TBCM C4227a-26, circuit CYB12 (YE/GN)/699 (OG), harness side and TBCM C4227a-34, circuit CYB13 (BU/GN)/698 (RD), harness side.

- Is the resistance 60-80 ohms?

Yes
GO to C6.

No
If the resistance is below 5 ohms, REPAIR circuits CYB12 (YE/GN)/699 (OG) and CYB13 (BU/GN)/698 (RD) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

All other values, GO to C7.

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C6 CHECK THE ACTUATOR DOOR

- Remove the rear A/C air filter.
- Measure the resistance between TBCM C4227a-17, circuit CYB10 (BU/WH)/1129 (BN/WH), harness side and TBCM C4227a-20, circuit VYB11 (GN/VT)/1130 (PK/LG), harness side.

- Observe the auxiliary airflow mode door.
- Connect a fused jumper between TBCM C4227a-10, circuit SBB05 (GY-RD), harness side and TBCM C4227a-34, circuit CYB13 (BU/GN)/698 (RD), harness side.

- Connect a fused jumper between TBCM C4227a-37, circuit GD149 (BK-GY), harness side and TBCM C4227a-26, circuit CYB12 (YE/GN)/699 (OG), harness side.

- Remove the fused jumpers.
- Connect a fused jumper between TBCM C4227a-37, circuit GD149 (BK-GY), harness side and TBCM C4227a-34, circuit CYB13 (BU/GN)/698 (RD), harness side.

- Connect a fused jumper between TBCM C4227a-10, circuit SBB05 (GY-RD), harness side and TBCM C4227a-26, circuit CYB12 (YE/GN)/699 (OG), harness side.

- Did the mode door move and the resistance increase and decrease when the fused jumpers were connected?

Yes
GO to C11.

No
If the mode door moved but the resistance did not change, GO to C7.

If the mode door did not move but the resistance changed, INSPECT for binding/damaged linkage or door. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

If the mode door did not move and the resistance did not change, GO to C9.

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C7 CHECK CIRCUITS ACTUATOR FEEDBACK CIRCUITS FOR AN OPEN IN THE BODY HARNESS

- Ignition OFF.
- Disconnect: In-line C406.
- Measure the resistance between the TBCM connector, harness side and in-line connector, body harness side using the following chart.

- Is the resistance less than 5 ohms?

Yes
GO to C8.

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

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C8 CHECK ACTUATOR FEEDBACK CIRCUITS FOR AN OPEN IN THE AUXILIARY HVAC HARNESS

- Ignition OFF.
- Disconnect: Auxiliary Mode Actuator C3256.
- Measure the resistance between the auxiliary mode actuator connector, harness side and in-line connector, auxiliary HVAC harness side using the following chart.

- Is the resistance less than 5 ohms?

Yes
GO to C10.

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

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C10 CHECK ACTUATOR MOTOR CIRCUITS FOR AN OPEN IN THE AUXILIARY HVAC HARNESS

- Ignition OFF.
- Disconnect: Auxiliary Mode Actuator C3256.
- Measure the resistance between the auxiliary mode actuator connector, harness side and in-line connector, auxiliary HVAC harness side using the following chart.

- Is the resistance less than 5 ohms?

Yes
INSTALL a new auxiliary mode actuator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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

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C11 CHECK THE TBCM CONNECTION

- Clear the DTCs.
- Disconnect all of the TBCM connectors.
- Check for:
- corrosion.
- pushed-out connectors.
- incorrectly seated connector.
- Connect and correctly seat all of the TBCM connectors.
- Operate the system.
- Does the concern return?

Yes
INSTALL a new TBCM. 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.

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