Conditions for Clearing the MIL/DTC

WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

This DTC will clear immediately after the condition for setting the fault is corrected.
A history DTC will clear after 100 consecutive ignition cycles without a fault present.
Use a scan tool in order to clear history and current DTCs.

DTC B2645

Step	Action	Value(s)	Yes	No
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference: Lighting Systems Connector End Views or Body Control System Connector End Views in Body Control System.
1	Did you perform the Lighting Systems Diagnostic System Check?	-	Go to Step 2	Go to Diagnostic System Check - Lighting Systems
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 in Wiring Systems	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 a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. Did you find and correct the condition?	-	Go to Step 10	Go to Step 9
8	Replace the ambient light sensor. Refer to Ambient Air Temperature Gage Sensor Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement?	-	Go to Step 10	-
9	IMPORTANT: Always perform the setup procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement in Body Control System. Perform the setup procedure for the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System. 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