For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC B0163 02: Passenger Compartment Temperature Sensor Circuit Short to Ground
DTC B0163 05: Passenger Compartment Temperature Sensor Circuit Short to Battery or Open
DTC B0183 02: Solar Load Sensor Circuit Short to Ground
DTC B0183 05: Solar Load Sensor Circuit Short to Battery or Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Sunload Sensor Signal | B0183 05 | B0183 02 | B0183 02 | 1
Passenger Compartment Temperature Sensor Signal | B0163 02 | B0163 05 | B0163 05 | 1
Ambient Light/Sunload Sensor Ground | -- | B0163 05, B0183 05 | -- | --
1. Air Temperature Malfunction

### Circuit/System Description

The ambient light/sunload sensor integrates the sunload sensor and passenger compartment temperature sensor.

This sensor assembly provides information about:

• | Sun heat intensity

• | Passenger Compartment Temperature

The solar sensor is connected to ground and to the 5 V stabilized voltage supply through the HVAC control module. As the sunload increases, the sensor signal voltage also increases and vice versa. The signal varies between 1.4-4.5 V and is provided to the HVAC control module.

The passenger compartment temperature sensor is a negative temperature co-efficient thermistor. A signal and low reference circuit enables the sensor to operate. As the air temperature increases, the sensor resistance decreases. The sensor signal varies between 0-5 V.

Bright or high intensity light causes the vehicles interior temperature to increase. The HVAC system compensates for the increased temperature by diverting additional cool air into the vehicle.

### Conditions for Running the DTC

• | Ignition ON.

• | The HVAC Control Module is ON.

### Conditions for Setting the DTC

#### B0163 02 or B0163 05

The HVAC Control module detects the sensor signal out of range. The signal voltage is less than 0.1 V or greater than 4.9 V for more than 50 ms.

#### B0183 02

The input signal is out of range. The voltage is less than 0.1 V.

#### B0183 05

The input signal is out of range. The voltage is greater than 4.9 V.

### Action Taken When the DTC Sets

• | The system will use the last valid values as default.

• | If no value is read at the time of fault, the HVAC control module uses 0 W/m² as intensity.

### Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

### Reference Information

#### Schematic Reference

HVAC Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Automatic HVAC Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Verify that DTC B0163 02 or B0163 05 is not present.

⇒ | If DTC is present, refer to Passenger Compartment Temperature Sensor Circuit Malfunction.

2. Verify that DTC B0183 02 or B0183 05 is not present.

⇒ | If DTC is present, refer to Sunload Sensor Circuit Malfunction.

3. Measure actual inside air temperature using a thermometer. Compare this value to the scan tool Passenger Compartment Air Temperature parameter. The measured temperature should be within 5°C (9°F) difference of parameter value.

⇒ | If not within the specified range, replace the B10B Ambient Light/Sunload Sensor.

### Circuit/System Testing

#### Passenger Compartment Temperature Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the B10B Ambient Light/Sunload Sensor.
2. Test for less than 5 Ω between the ground circuit terminal 6 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, test for 4.8-5.2 V between the ground circuit terminal 6 and the signal circuit terminal 3.

⇒ | If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K33 HVAC Control Module.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K33 HVAC Control Module.

4. If all circuits test normal, replace the B10B Ambient Light/Sunload Sensor and verify the DTC does not reset.

⇒ | If the DTC resets, replace the K33 HVAC Control Module.

#### Sunload Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the B10B Ambient Light/Sunload Sensor.
2. Ignition ON, test for 4.8-5.2 V between the ground circuit terminal 6 and the signal circuit terminal 4.

⇒ | If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K33 HVAC Control Module.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K33 HVAC Control Module.

3. If all circuits test normal, replace the B10B Ambient Light/Sunload Sensor and verify the DTC does not reset.

⇒ | If the DTC resets, replace the K33 HVAC Control Module.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Sun Load Temperature and Headlamp Automatic Control Ambient Light Sensor Replacement

• | Control Module References for HVAC control module replacement, setup, and programming