For 1990-2009 cars

## DTC 015 LH Sunload Sensor Circuit Open or Shorted Buick, Oldsmobile

HVAC Components
Cell 68: IP Fuse Block, DLC - Oldsmobile
Cell 68: IP Fuse Block, DLC (Buick)
Handling ESD Sensitive Parts Notice
HVAC Air Delivery/Temperature Control Schematics
HVAC Air Delivery/Temperature Control Schematics

### Circuit Description

The left sun load sensor is a light sensitive photodiode that controls signal voltage to the HVAC programmer. This photodiode is different from standard thermistor sensors and resistance measurements will not produce accurate results. The HVAC programmer monitors voltage on CKT 590 to the sensor. When the sensor is in direct sun light, the HVAC programmer reads a low signal voltage at terminal F10. When the sensor is shaded, the signal voltage increases. Signal voltage will vary from 5 V (open circuit) to 0 V (short circuit).

### Conditions for Setting the DTC

• | The ignition is ON.

• | Circuit open or shorted.

### Action Taken When the DTC Sets

• | The HVAC programmer will default the system to dark or no sun load value.

• | The default value allows the system to operate.

### Conditions for Clearing the MIL/DTC

• | Using a Scan Tool .

• | A history DTC will clear after 40 consecutive IGN cycles have occurred without a malfunction.

• | HVAC programmer battery voltage is interrupted.

### Test Description

1. Determines whether the sensor is operational.

2. Determines that the DTC was not set in error.

3. Determines if the malfunction is the sensor or an open or a short in a circuit.

4. Determines if the HVAC programmer or an open or short is causing the malfunction.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Ensure the vehicle is in a sunlit area.
2. Turn the ignition switch to the RUN position.
3. Connect the Scan Tool .
4. Display the LH solar sensor.

Note the value.

5. Cover the LH sun load sensor with a dense object.

Did the sensor counts increase from the noted value?

--

Go to Step 2

Go to Step 3

2 |

1. Use a Scan Tool in order to clear the DTC.
2. Cycle the engine to the ON position and the OFF position several times.

Did the DTC reset?

--

Go to Step 3

Go to Intermittents and Poor Connections .

3 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the LH sun load sensor.
3. Turn the ignition switch to the RUN position.
4. Measure the voltage between sun load sensor harness connector terminal A and terminal B.

Refer to Measuring Voltage in Wiring Systems.

Does the voltage equal the specified value?

5 V

Go to Step 9

Go to Step 4

4 | Is the voltage greater than the specified value? | 5 V | Go to Step 5 | Go to Step 6
5 | Repair the short to the battery in CKT 590. Refer to Wiring Repairs in Wiring Systems. Is the repair compete? | -- | Go to Step 6 | --
6 | Measure the voltage between sun load sensor harness connector terminal A and DLC terminal 4. Refer to Measuring Voltage in Wiring Systems. Does the voltage equal the specified value? | 5 V | Go to Step 10 | Go to Step 7
7 | Measure the voltage between HVAC programmer terminal F10 and DLC terminal 4. Refer to Measuring Voltage in Wiring Systems. Does the voltage equal the specified value? | 5 V | Go to Step 8 | Go to Step 11
8 | Repair the open in CKT 590. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
9 | Replace the sensor. Refer to Sun Load Sensor Replacement . Is the repair complete? | -- | System OK | --
10 | Are all of the HVAC sensor DTCs present? | -- | Go to Step 11 | Go to Step 12
11 |

1. Inspect for proper terminal contact. Refer to Intermittents and Poor Connections .
2. Replace the HVAC programmer if terminal contact is OK. Refer to Programmer Replacement .

Is the repair complete?

--

System OK

--

12 | Repair the open in CKT 1704. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --

## DTC 015 LH Sunload Sensor Circuit Open or Shorted Pontiac

HVAC Components
Cell 68: Heater and A/C Programmer - Pontiac
Handling ESD Sensitive Parts Notice
HVAC Air Delivery/Temperature Control Schematics
HVAC Air Delivery/Temperature Control Schematics

### Circuit Description

The sun load temperature sensor is a light sensitive photodiode that controls signal voltage to the HVAC programmer. This photodiode is different from standard thermistor sensors and resistance measurements will not produce accurate results. The HVAC programmer monitors voltage on CKT 590 to the sensor. When the sensor is in direct sun light, the HVAC programmer reads a low signal voltage at terminal D10. When the sensor is shaded, the signal voltage increases. Signal voltage will vary from 5 V (open circuit) to 0 V (short circuit).

### Conditions for Setting the DTC

• | The ignition is ON.

• | Circuit open or shorted.

### Action Taken When the DTC Sets

• | The HVAC programmer will default the system to dark or no sun load value.

• | The default value allows the system to operate.

### Conditions for Clearing the DTC

• | Using a Scan Tool .

• | A history DTC will clear when 40 consecutive IGN cycles have occured without a malfunction.

• | HVAC programmer battery voltage is interrupted.

### Test Description

1. Determines whether the sensor is operational.

2. Determines that the DTC was not set in error.

3. Determines if the malfunction is the sensor or an open or a short in a circuit.

4. Determines if the HVAC programmer or an open or short is causing the malfunction.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Ensure the vehicle is in a sunlit area.
2. Turn the ignition switch to the RUN position.
3. Connect the Scan Tool .
4. Display the left solar sensor.

Note the value.

5. Cover the sun load temperature sensor with a dense object.

Did the sensor counts increase from the noted value?

--

Go to Step 2

Go to Step 3

2 |

1. Use a Scan Tool to clear the DTC.
2. Cycle the engine to the ON position and the OFF position several times.

Did the DTC reset?

--

Go to Step 3

Go to Intermittents and Poor Connections .

3 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the sun load sensor.
3. Turn the ignition switch to the RUN position.
4. Measure the voltage between sun load sensor harness connector terminal A and terminal B.

Refer to Measuring Voltage in Wiring Systems.

Does the voltage equal the specified value?

5 V

Go to Step 9

Go to Step 4

4 | Is the voltage greater than the specified value? | 5 V | Go to Step 5 | Go to Step 6
5 | Repair the short to the battery in CKT 590. Refer to Wiring Repairs in Wiring Systems. Is the repair compete? | -- | Go to Step 6 | --
6 | Measure the voltage between sun load sensor harness connector terminal A and DLC terminal 4. Refer to Measuring Voltage in Wiring Systems. Does the voltage equal the specified value? | 5 V | Go to Step 10 | Go to Step 7
7 | Measure the voltage between HVAC programmer terminal D10 and DLC terminal 4. Refer to Measuring Voltage in Wiring Systems. Does the voltage equal the specified value? | 5 V | Go to Step 8 | Go to Step 11
8 | Repair the open in CKT 590. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
9 | Replace the sensor. Refer to Sun Load Sensor Replacement . Is the repair complete? | -- | System OK | --
10 | Are all of the HVAC sensor DTCs present? | -- | Go to Step 11 | Go to Step 12
11 |

1. Inspect for proper terminal contact.

Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

2. Replace the HVAC programmer if terminal contact is OK. Refer to Programmer Replacement .

Is the repair complete?

--

System OK

--

12 | Repair the open in CKT 1704. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --