2010 Cadillac CTS Sedan AWD V6-3.6L Page 194

2010 Cadillac CTS Sedan AWD V6-3.6L Page 194

3. Ignition ON, test for 4.8-5.2 volts between the ground circuit terminal C and the appropriate signal circuit terminal listed below:

* Left solar load sensor circuit terminal A.

* Right solar load sensor circuit terminal B.

瀚慖f 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

HVAC control module.

瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control

module.

4. If all circuits test normal, test or replace the sunload sensor.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* Headlamp Automatic Control Ambient Light Sensor Replacement (See: Lighting and Horns/Headlamp/Headlamp Dimmer Sensor/Service

and Repair)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for HVAC control module replacement, setup, and

programming

B0188

DTC B0183 or B0188

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC B0183 06

- Solar Load Sensor 1 Circuit Short to Ground or Open

DTC B0188 06

- Solar Load Sensor 2 Circuit Short to Ground or Open

Diagnostic Fault Information

Circuit Description

The vehicle uses left and right sunload sensors that are integrated into one sensor assembly along with the ambient light sensor. Low reference and

signal circuits enable the sensor to operate. The sensor signal varies between 0 and 5 volts. The HVAC control module converts the signal to a

range between 0 and 255 counts. The sunload sensor provides the HVAC control module with a measurement of the amount of light shining on the

vehicle. 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.

The following DTCs are for the left and right sunload sensors.

* B0183 is for the left sunload sensor.

* B0188 is for the right sunload sensor.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC