Circuit Description
The daytime running lamps (DRL) relay is controlled by the body control module (BCM). Ignition positive voltage is applied to the DRL relay coil. 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 ground, DTC B2601 is set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2601 Daytime Running Lamp Control System Circuit Range/Performance
Conditions for Running the DTC
| • | The ignition switch is in the ON position. |
| • | The headlamp switch is in the OFF position. |
| • | The transaxle is in park. |
Conditions for Setting the DTC
All of the following conditions must be met:
| • | The BCM is not commanding the DRL relay on. |
| • | The headlamp feedback is present for 5 seconds. |
Action Taken When the DTC Sets
| • | The BCM disables the DRL relay control as long as the malfunction is present. |
| • | The SERVICE indicator illuminates. |
Conditions for Clearing the DTC
| • | 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. |
Diagnostic Aids
| • | If DTC B2602 is set along with DTC B2601, test the DRL relay control circuit between the BCM and the DRL relay for a short to ground. |
| • | The park brake must be unapplied and the transaxle must be in gear for the DRLs to operate properly. |
| • | Intermittent malfunctions are cumulative. When the malfunction exists for a total of 5 seconds, DTC B2601 is set. |
| • | If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Does the DRL relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
3 | Test the control circuit of the DRL relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 6 | Go to Step 4 |
4 | 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 in Wiring Systems. Did you find and correct the condition? | Go to Step 6 | Go to Step 5 |
5 | Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 6 | -- |
6 |
Does the DTC reset? | Go to Step 2 | System OK |
