Operation CHARM: Car repair manuals for everyone.

Pinpoint Test C: DTCs C1B14:11 and 12




Climate Control System

Pinpoint Tests

Pinpoint Test C: DTCs C1B14:11 and 12

Refer to Wiring Diagram Set 54 (Fusion/Milan/MKZ, Fusion Hybrid/Milan Hybrid), Manual Climate Control System for schematic and connector information. Diagrams By Number

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

Normal Operation

Under normal operation, a 5-volt reference voltage is supplied to the sensors and actuators from the HVAC module through circuit LH111 (BN/WH).

- DTC C1B14:11 (Sensor Supply Voltage A: Circuit Short to Ground) - The module senses less than 0.1 volt on the sensor reference voltage circuit, indicating a short directly to ground.
- DTC C1B14:12 (Sensor Supply Voltage A: Circuit Short to Battery) - The module senses greater than 4.9 volts on the sensor reference voltage circuit, indicating a short directly to voltage.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- HVAC module



PINPOINT TEST C: DTCs C1B14:11 AND 12

-------------------------------------------------
C1 CHECK THE SENSOR RESISTANCE


- Check for HVAC DTCs.
- Is DTC C1B14:11 present?

Yes
GO to C2.

No
GO to C4.

-------------------------------------------------
C2 CHECK CIRCUIT LH111 (BN/WH) FOR A SHORT TO GROUND


- Ignition OFF.
- Disconnect: HVAC Module - Electronic Manual Temperature Control (EMTC) C2357a.
- Disconnect: HVAC Module - Dual Automatic Temperature Control (DATC) C2356a.
- Disconnect: HVAC Module - DATC C2356b.
- Measure the resistance between ground and HVAC module - EMTC C2357a-11 or HVAC module - DATC C2356a-11, circuit LH111 (BN/WH), harness side.




- Is the resistance greater than 10,000 ohms?

Yes
GO to C3.

No
REPAIR circuit LH111 (BN/WH) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

-------------------------------------------------
C3 CHECK CIRCUITS LH111 (BN/WH) AND RH111 (GY/BU) FOR A SHORT TOGETHER


- Measure the resistance between HVAC module - EMTC C2357a-11 or HVAC module - DATC C2356a-11, circuit LH111 (BN/WH), harness side and HVAC module - EMTC C2357a-10 or HVAC module C2356a-10, circuit RH111 (GY/BU), harness side.




- Is the resistance greater than 200 ohms?

Yes
GO to C5.

No
REPAIR circuits LH111 (BN/WH) and RH111 (GY/BU) for a short together. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

-------------------------------------------------
C4 CHECK CIRCUIT LH111 (BN/WH) FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: HVAC Module - EMTC C2357a.
- Disconnect: HVAC Module - DATC C2356a.
- Disconnect: HVAC Module - DATC C2356b.
- Ignition ON.
- Measure the voltage between ground and HVAC module - EMTC C2357a-11 or HVAC module - DATC C2356a-11, circuit LH111 (BN/WH), harness side.




- Is any voltage present?

Yes
REPAIR circuit LH111 (BN/WH) for a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
GO to C5.

-------------------------------------------------
C5 CHECK THE MODULE CONNECTION


- Inspect the 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. 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.

-------------------------------------------------