Diagnostic Routine E

Diagnostic Routine E

Diagnostic Overview

B1A63:11, B1A63:15, B1A64:11, B1A64:15

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

Normal Operation and Fault Conditions

As the light applied to the sensor changes, the HVAC (Heating, Ventilation, and Air Conditioning) module detects the change through the RH (Right Hand) and LH (Left Hand) feedback circuits.

DTC Fault Trigger Conditions






Pinpoint Test

1. CHECK THE AUTOLAMP/SUNLOAD SENSOR REFERENCE VOLTAGE

1. Ignition OFF.

2. Disconnect: Autolamp/Sunload Sensor.

3. Ignition ON.

4. Press the AUTO button.

5. For DTC (Diagnostic Trouble Code) B1A63:11 or B1A63:15, measure:





6. For DTC (Diagnostic Trouble Code) B1A64:11 or B1A64:15, measure:





Is the voltage between 4.7 and 5.1 volts?








2. CHECK THE AUTOLAMP/SUNLOAD SENSOR GROUND CIRCUIT FOR AN OPEN

1. Ignition OFF.

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

3. Measure:





Is the resistance less than 3 ohms?








3. CHECK THE AUTOLAMP/SUNLOAD SENSOR FEEDBACK CIRCUITS FOR AN OPEN

1. For DTC (Diagnostic Trouble Code) B1A63:15, measure:





2. For DTC (Diagnostic Trouble Code) B1A64:15, measure:





Is the resistance less than 3 ohms?








4. CHECK THE AUTOLAMP/SUNLOAD SENSOR FEEDBACK CIRCUITS FOR A SHORT TO VOLTAGE

1. For DTC (Diagnostic Trouble Code) B1A63:15, measure:





2. For DTC (Diagnostic Trouble Code) B1A64:15, measure:





Is the resistance greater than 10,000 ohms?








5. CHECK THE AUTOLAMP/SUNLOAD SENSOR FEEDBACK CIRCUITS FOR A SHORT TO GROUND

1. Ignition OFF.

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

3. For DTC (Diagnostic Trouble Code) B1A64:11, measure:





4. For DTC (Diagnostic Trouble Code) B1A63:11, measure:





Is the resistance greater than 10,000 ohms?








6. 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?