Diagnostic Routine AI

Diagnostic Routine AI

Diagnostic Overview

B1A69:11, B1A69:15

Refer to Wiring Diagram Set 55 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

REFER to In-Vehicle Temperature and Humidity Sensor .

DTC Fault Trigger Conditions






Pinpoint Test

1. CHECK FOR HVAC (Heating, Ventilation, and Air Conditioning) MODULE DTCs (Diagnostic Trouble Codes)

1. Ignition ON.

2. Using a scan tool, perform a HVAC (Heating, Ventilation, and Air Conditioning) module self-test.

Are DTCs (Diagnostic Trouble Codes) C1B14:11 or C1B14:12 present?






2. CHECK FOR VOLTAGE TO THE IN-VEHICLE TEMPERATURE SENSOR/HUMIDITY SENSOR

1. Ignition OFF.

2. Disconnect: In-Vehicle Temperature/Humidity Sensor.

3. Ignition ON.

4. Measure:





Is the voltage between 4.7 and 5 volts?








3. CHECK THE HUMIDITY SIGNAL CIRCUIT FOR A SHORT TO GROUND

1. Ignition OFF.

2. Disconnect: HVAC (Heating, Ventilation, and Air Conditioning) Module C228A

3. Measure:





Is the resistance greater than 10,000 ohms?








4. CHECK THE HUMIDITY SIGNAL CIRCUIT FOR AN OPEN CIRCUIT

1. Ignition OFF.

2. Disconnect: HVAC (Heating, Ventilation, and Air Conditioning) Module C228B.

3. Measure:





Is the resistance less than 3 ohms?








5. CHECK THE HUMIDITY SIGNAL CIRCUIT FOR A SHORT TO POWER

1. Ignition ON.

2. Measure:





Is any voltage present?








6. ISOLATE THE IN-VEHICLE TEMPERATURE SENSOR/HUMIDITY SENSOR

1. Ignition OFF.

2. Connect: HVAC (Heating, Ventilation, and Air Conditioning) Module C228A.

3. Connect: HVAC (Heating, Ventilation, and Air Conditioning) Module C228B.

4. Install a new in-vehicle temperature sensor/humidity sensor. REFER to In-Vehicle Temperature Sensor .

5. Ignition ON.

6. Using a scan tool, perform a HVAC (Heating, Ventilation, and Air Conditioning) module self-test.

Does the DTC (Diagnostic Trouble Code) return?






7. CHECK FOR CORRECT HVAC (Heating, Ventilation, and Air Conditioning) MODULE OPERATION

1. Ignition OFF.

2. Disconnect and inspect all HVAC (Heating, Ventilation, and Air Conditioning) module connectors.

3. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged or bent pins- install new terminals/pins
- pushed-out pins- install new pins as necessary

4. Reconnect the HVAC (Heating, Ventilation, and Air Conditioning) module connectors. Make sure they seat and latch correctly.

5. Operate the system and determine if the concern is still present.

Is the concern still present?