The daytime running lamps (DRL) relay is controlled by the body control module (BCM). Battery positive voltage is applied to the relay coil at all times. The BCM grounds the DRL relay control circuit in order to turn ON the DRL relay. When the DRL relay control circuit becomes shorted to battery positive voltage, DTC B2603 is set.
This diagnostic procedure supports the following DTC:
DTC B2603 Daytime Running Lamp Circuit High
The ignition switch is in the ON position.
• | The BCM is commanding the DRL relay ON. |
• | The headlamp feedback is not present for 1 second. |
• | The BCM disables the DRL relay control as long as the malfunction is present. |
• | The SERVICE indicator illuminates. |
• | The conditions for setting the DTC are no longer present. |
• | A history DTC clears after 100 malfunction-free ignition cycles. |
• | The BCM receives the clear code command from the scan tool. |
• | The park brake must be unapplied and the transaxle must be in gear for the DRL to operate properly. |
• | If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections . |
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the DRL relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 5 |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 6 |
5 | Inspect for poor connections at the DRL relay. 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 |
6 | Inspect for poor connections at the harness connector of the body control module (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 |
7 | Repair a short to voltage in the DRL relay control circuit. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 10 | -- |
8 | Replace the DRL relay. 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 |
Does the DTC reset? | Go to Step 3 | System OK |