Diagnostic Aids

WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

The following may cause an intermittent:
- Bent terminal
- Backed out terminal
- Damaged terminal
- Poor terminal tension
- Chafed wire
- Broken wire inside the insulation
When diagnosing for an intermittent short or an open, manipulate the wire harness while watching the test equipment for changes.

DTC B2645

Step	Action	Values	Yes	No
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference: Master Electrical Component List
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to DIAGNOSTIC SYSTEM CHECK - VEHICLE
2	Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, observe the Ambient Light Sensor parameter in the body control module (BCM) data list. Does the scan tool indicate that the Ambient Light Sensor parameter is within the specified range?	1.75-4.9 V	Go to Testing for Intermittent Conditions and Poor Connections	Go to Step 3
3	Turn OFF the ignition. Disconnect the ambient light sensor. Turn ON the ignition, with the engine OFF. With a scan tool, observe the Ambient Light Sensor parameter. Does the scan tool indicate that the Ambient Light Sensor parameter is less than the specified value?	0.02 V	Go to Step 4	Go to Step 5
4	Test the ambient light sensor circuit of the ambient light sensor for the following: An open A high resistance A short to ground Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 10	Go to Step 6
5	Test the ambient light sensor signal circuit of the ambient light sensor for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 10	Go to Step 7
6	Inspect for poor connections at the harness connector of the ambient light sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 10	Go to Step 8
7	Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 10	Go to Step 9
8	Replace the ambient light sensor. Refer to Ambient Light Sensor Replacement . Did you complete the replacement?	-	Go to Step 10	-
9	Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 10	-
10	Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text. Does the DTC reset?	-	Go to Step 2	System OK