Pinpoint Test C: DTC C1B14:11 and C1B14:12

Climate Control System

Pinpoint Tests

Pinpoint Test C: DTC C1B14:11 and C1B14:12

Refer to Wiring Diagram Set 55, 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.

- 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: DTC C1B14:11 AND C1B14:12

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C1 CHECK THE HVAC DTCs


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

Yes
GO to C2.

No
GO to C3.

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C2 CHECK THE REFERENCE VOLTAGE CIRCUIT FOR A SHORT TO GROUND


- Ignition OFF.
- Disconnect: HVAC Module C228A/C2356A.
- Disconnect: HVAC Module C228B/C2356B.
- Measure the resistance between ground and HVAC module C228A/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.

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C3 CHECK THE REFERENCE VOLTAGE CIRCUIT FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: HVAC Module C228A/C2356A.
- Disconnect: HVAC Module C228B/C2356B.
- Measure the voltage between ground and HVAC module C228A/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 C4.

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C4 CHECK THE HVAC 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. REFER to Climate Control Service and Repair. 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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