Test Description

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The number(s) below refer to the step number(s) on the diagnostic table.

Tests ambient light sensor data using a scan tool.
Tests the ambient light sensor data with the sensor disconnected. The scan tool will display ambient light sensor voltage as 0 volts with the sensor disconnected.
Tests the ambient light sensor data with a jumper wire between the reference and signal circuit. The scan tool will display ambient light sensor voltage between 3.5-4.5 volts with the sensor jumpered.
Tests for a short to voltage in the DRL ambient light sensor low reference circuit.

Fig 1: DTC B2647 (1 Of 2)
Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC B2647 (2 Of 2)
Courtesy of GENERAL MOTORS CORP.