Pinpoint Test F: DTC B2826 Or B2827
WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
- F1 CHECK THE SENSOR RESISTANCE
- Ignition OFF.
- Disconnect: Evaporator Discharge Air Temperature Sensor C296.
- Allow enough time for the evaporator to stabilize to the outside ambient temperature.
- Measure the resistance between evaporator discharge air temperature sensor C296 terminals and compare to the table below.RESISTANCE AND TEMPERATURE CHART
Ambient Temperature Resistance -40°C (-40°F) 832,591-1,017,523 ohms -20°C (-4°F) 263,111-290,807 ohms 0°C (32°F) 91,058-100,644 ohms 20°C (68°F) 35,473-39,207 ohms 25°C (77°F) 28,500-31,500 ohms 40°C (104°F) 15,307-16,919 ohms 60°C (140°F) 7,171-7,925 ohms 100°C (212°F) 1,976-2,184 ohms 120°C (248°F) 1,131-1,251 ohms - Is the resistance within the specified values for the temperatures?
- Yes: GO to F2 .
- No: INSTALL a new evaporator discharge air temperature sensor. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
- F2 CHECK THE HVAC OUTPUT VOLTAGE
- Ignition ON.
- Press the power button.
- Measure the voltage between evaporator discharge air temperature sensor C296-1, circuit VH406 (VT/BN), harness side and C296-2, circuit RH111 (GY/BU), harness side.
- Is the voltage between 4.7 and 5.1 volts?
- F3 CHECK CIRCUIT VH406 (VT/BN) FOR AN OPEN
- Ignition OFF.
- Disconnect: HVAC Module - EMTC C2357A or HVAC Module - DATC C2356A.
- Measure the resistance between HVAC module - EMTC C2357A-6 or HVAC module - DATC C2356A-6, circuit VH406 (VT/BN), harness side and evaporator discharge air temperature sensor C296-1, circuit VH406 (VT/BN), harness side.
- Is the resistance less than 5 ohms?
- Yes: GO to F4 .
- No: REPAIR circuit VH406 (VT/BN) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
- F4 CHECK CIRCUIT RH111 (GY/BU) FOR AN OPEN
- Measure the resistance between HVAC module - EMTC C2357A-10 or HVAC module - DATC C2356A-10, circuit RH111 (GY/BU), harness side and evaporator discharge air temperature sensor C296-2, circuit RH111 (GY/BU), harness side.
- Is the resistance less than 5 ohms?
- Yes: GO to F7.
- No: REPAIR circuit RH111 (GY/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
- F5 CHECK CIRCUIT VH406 (VT/BN) FOR A SHORT TO CIRCUIT RH111 (GY/BU)
- Ignition OFF.
- Disconnect: HVAC Module - EMTC C2357A or HVAC Module - DATC C2356A.
- Measure the resistance between evaporator discharge air temperature sensor C296-1, circuit VH406 (VT/BN), harness side and C296-2, circuit RH111 (GY/BU), harness side.
- Is the resistance greater than 10,000 ohms?
- Yes: GO to F6 .
- No: REPAIR circuit VH406 (VT/BN) for a short to circuit RH111 (GY/BU). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
- F6 CHECK CIRCUIT VH406 (VT/BN) FOR A SHORT TO GROUND
- Measure the resistance between HVAC module - EMTC C2357A-6 or HVAC module - DATC C2356A-6, circuit VH406 (VT/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- Yes: GO to F7 .
- No: REPAIR circuit VH406 (VT/BN) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
- F7 CHECK THE HVAC MODULE CONNECTION
- Inspect the HVAC module connectors for:
- corrosion.
- pushed-out terminals.
- damaged terminals.
- Connect and correctly seat all the HVAC module connectors.
- Clear the DTCs.
- 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 . 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.
- Inspect the HVAC module connectors for: