• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ambient Light/Sunload Sensor 12 V Reference | B1405 02 | B1405 05 | B1405 05 | -- |
Passenger Compartment Temperature Sensor Signal | B0163 02 | B0163 05 | B0163 05 | 1 |
Sunload Sensor Signal | B0183 02 | B0183 05 | B0183 05 | 1 |
Ambient Light/Sunload Sensor Ground | -- | B0163 05, B0183 05, B1405 05 | -- | -- |
1. Air Temperature Malfunction |
The ambient light/sunload sensor includes the sunload sensor and passenger compartment temperature sensor.
This sensor assembly provides information about:
• | Sun heat intensity |
• | Elevation |
• | Azimuth |
• | Passenger compartment temperature |
The sunload sensor is connected to ground and to a 12 V clocked power supply through the HVAC control module. This clocked power supply is to power the sensor electronics and to work as a clock generator to the sunload sensor micro controller. The sensor uses a pulse signal for data identification and transferring the sun intensity measurement. At each positive transition from the clocked supply input, the sunload sensor micro controller will shift channels enabling new intensity measurement on the signal output to the HVAC control module. The signal voltage varies between 0-4 V.
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.
• | Ignition ON. |
• | The HVAC control module is ON. |
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.
The 5 V identification pulse is not received.
The input signal is static and greater than 4.8 V.
Clocked supply for multi zone sensor is shorted to ground.
Clocked supply for multi zone sensor is shorted to voltage or open.
• | 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, 45° for elevation and -75° for azimuth. |
The sensor signal is within specified range between 0.1 V and 4.9 V.
The 5 V identification pulse will be received.
The correct pulse signal succession will be received.
The condition for setting the DTC is no longer present.
LINK
Automatic HVAC Description and Operation
Control Module References for scan tool information
⇒ | If DTC is present, refer to Ambient Light/Sunload Sensor Power Supply Malfunction. |
⇒ | If DTC is present, refer to Passenger Compartment Temperature Sensor Circuit Malfunction. |
⇒ | If DTC is present, refer to Sunload Sensor Circuit Malfunction. |
⇒ | If not within the specified range, replace the B10B Ambient Light/Sunload Sensor. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If greater than the specified range, test the reference voltage circuit for a short to voltage. |
⇒ | If less than the specified value, test the reference voltage circuit for a short to ground. |
⇒ | If greater than the specified value, test the reference voltage circuit for an open/high resistance. |
⇒ | If the DTC resets, replace the K33 HVAC Control Module. |
⇒ | If less than the specified range, test the signal circuit terminal 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 terminal for a short to battery. If the circuit tests normal, replace the K33 HVAC Control Module. |
⇒ | If the DTC resets, replace the K33 HVAC Control Module. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. |
⇒ | If less than the specified value, test the signal circuit for a short to ground. |
⇒ | If greater than the specified value, test the signal circuit for an open/high resistance. |
⇒ | If the DTC resets, replace the K33 HVAC Control Module. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for HVAC Control Module replacement, setup, and programming |