Pinpoint Test B: DTC B2784 Or DTC B2783 - Interior Humidity Sensor To DATC Open Or Short Circuit
Climate Control System
Pinpoint Tests
Pinpoint Test B: DTC B2784 or DTC B2783 - Interior Humidity Sensor to DATC Open or Short Circuit
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
Under normal operation, the A/C humidity sensor is grounded through circuit RH111 (GY/BU). A 5-volt reference voltage is supplied to the A/C humidity sensor from the HVAC module through circuit LH115 (WH). The HVAC module receives the humidity value through circuit VH413 (WH/BU).
- DTC B2784 Interior Humidity Sensor to DATC Open Circuit - The module senses no voltage drop on the sensor reference voltage circuit, indicating an open circuit.
- DTC B2783 Interior Humidity Sensor to DATC Short Circuit - The module senses excessive voltage drop on the sensor reference voltage circuit, indicating a short directly to ground.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- A/C humidity sensor
- HVAC module
PINPOINT TEST B: DTC B2784 OR DTC B2783 - INTERIOR HUMIDITY SENSOR TO DATC OPEN OR SHORT CIRCUIT
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B1 CHECK THE A/C HUMIDITY SENSOR VOLTAGE INPUT
- Ignition OFF.
- Disconnect: A/C Humidity Sensor C2247.
- Ignition ON.
- Press the AUTO button on the HVAC module.
- Measure the voltage between A/C humidity sensor C2247-2, circuit LH115 (WH), harness side and ground.
- Is the voltage between 4.7 and 5.1 volts?
Yes
GO to B4.
No
GO to B2.
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B2 CHECK CIRCUIT LH115 (WH) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: HVAC Module C2356b.
- Ignition ON.
- Measure the voltage between A/C humidity sensor C2247-2, circuit LH115 (WH), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit LH115 (WH) for a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to B3.
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B3 CHECK CIRCUIT LH115 (WH) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between HVAC module C2356b-9, circuit LH115 (WH), harness side and A/C humidity sensor C2247-2, circuit LH115 (WH).
- Is the resistance less than 5 ohms?
Yes
GO to B10.
No
REPAIR circuit LH115 (WH) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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B4 CHECK THE A/C HUMIDITY SENSOR GROUND
- Measure the voltage between A/C humidity sensor C2247-2, circuit LH115 (WH), harness side and A/C humidity sensor C2247-3, circuit RH111 (GY/BU), harness side.
- Is the voltage between 4.7 and 5.1 volts?
Yes
GO to B6.
No
GO to B5.
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B5 CHECK CIRCUIT RH111 (GY/BU) FOR AN OPEN
- Ignition OFF.
- Disconnect: HVAC Module C2356a.
- Measure the resistance between HVAC module C2356a-10, circuit RH111 (GY/BU), harness side and A/C humidity sensor C2247-3, circuit RH111 (GY/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B10.
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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B6 CHECK CIRCUIT VH413 (WH/BU) FOR AN OPEN
- Ignition OFF.
- Disconnect: HVAC Module C2356b.
- Measure the resistance between HVAC module C2356b-22, circuit VH413 (WH/BU), harness side and A/C humidity sensor C2247-4, circuit VH413 (WH/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B7.
No
REPAIR circuit VH413 (WH/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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B7 CHECK CIRCUIT VH413 (WH/BU) FOR A SHORT TO CIRCUIT RH111 (GY/BU)
- Disconnect: HVAC Module C2356a.
- Measure the resistance between HVAC module C2356b-22, circuit VH413 (WH/BU), harness side and HVAC module C2356a-10, circuit RH111 (GY/BU), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B8.
No
REPAIR circuit VH413 (WH/BU) for a short to circuit RH111 (GY/BU). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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B8 CHECK CIRCUIT VH413 (WH/BU) FOR A SHORT TO GROUND
- Measure the resistance between HVAC module C2356b-22, circuit VH413 (WH/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B9.
No
REPAIR circuit VH413 (WH/BU) for a short ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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B9 CHECK THE A/C HUMIDITY SENSOR VOLTAGE OUTPUT
- Ignition ON.
- Measure the voltage between A/C humidity sensor C2247-4, circuit VH413 (WH/BU) and ground by back-probing the sensor.
- Is the voltage between 0.3 and 4.3 volts?
Yes
GO to B10.
No
INSTALL a new A/C humidity sensor. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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B10 CHECK THE MODULE CONNECTION
- Carry out the HVAC Module Cold Boot Process. HVAC Module Cold Boot Process
- Carry out the HVAC On-Demand Self Test. HVAC Module - Diagnostic Methods
- 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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