FixVault
Home › Cadillac › 2000 › Catera › Repair and Diagnosis › Body & Frame › Body, Cab Control Systems › Body Control Modules › Diagnostic Tests › DTC B2470: Daytime Running Lights Fault › Testing

DTC B2470: Daytime Running Lights Fault: Testing

  1. Perform lighting system diagnostic system check. See LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
  2. Turn ignition off. Connect scan tool to DLC. Select DAYTIME RUNNING LIGHTS from light test menu in SPECIAL FUNCTIONS. While observing scan tool, press on and off buttons on scan tool several times. If status changes and DRL operates with commanded state, go to next step. If status does not change or DRL does not operate with commanded state, go to DIAGNOSTIC AIDS  .
  3. Check LH HIGH BEAM fuse (10-amp) in fuse block for an open. If fuse is open, go to step  13 . If fuse is not open, go to next step.
  4. Remove DRL relay from relay box. See Figure . Using a test light connected to ground, probe Red wire at DRL relay terminal No. 3. If test lamp illuminates, go to next step. If test lamp does not illuminate, go to step  11 .
  5. Connect test light between DRL relay terminals No. 1 (Brown/Purple wire) and No. 3 (Red wire). Using scan tool, command DRL relay on and off. If test light turns on and off when DRL relay is turned on and off by scan tool, go to step  9 . If test light does not turn on and off when DRL relay is turned on and off by scan tool, go to next step.
  6. If test light remains illuminated each time DRL relay is turned on and off by scan tool in above step, go to step  12 . If test light does not remain illuminated each time DRL relay is turned on and off by scan tool in above step, go to next step.
  7. Using DVOM, test Brown/Purple wire between BCM 32-pin connector C2 terminal C5 and DRL relay terminal No. 1 for an open or high resistance. If fault is located and repaired, go to step  16 . If fault is not located and repaired, go to next step.
  8. Using DVOM, test Brown/Purple wire between BCM 32-pin connector C2 terminal C5 and DRL relay terminal No. 1 for short to battery voltage. If fault is located and repaired, go to step  16 . If fault is not located and repaired, go to step  10 .
  9. Inspect for poor connections at DRL relay. If fault is located and repaired, go to step  16 . If fault is not located and repaired, go to step  14 .
  10. Inspect for poor connections at BCM harness connectors. If fault is located and repaired, go to step  16 . If fault is not located and repaired, go to step  15 .
  11. Locate and repair open circuit in Red wire between DRL relay terminal No. 3 and LH HIGH BEAM fuse (10-amp) in fuse block. After fault is repaired, go to step  16 .
  12. Locate and repair short to ground in Brown/Purple wire between DRL relay terminal No. 1 and BCM 32-pin connector C2 terminal C5. After fault is repaired, go to step  16 .
  13. Locate and repair short to ground in one of the following circuits:
    • Red wire between DRL relay terminal No. 3 and LH HIGH BEAM fuse (10-amp) in fuse block.
    • Red wire between DRL relay terminal No. 5 and LH HIGH BEAM fuse (10-amp) in fuse block.
    • Red wire between LH headlight relay (high beam) terminal No. 3 and LH HIGH BEAM fuse (10-amp) in fuse block.

    After fault is repaired, go to step  16 .

  14. Replace DRL relay. See REMOVAL & INSTALLATION  . After replacement, go to step  16 .
  15. Replace BCM. See BODY CONTROL MODULE (BCM)  under REMOVAL & INSTALLATION. Reprogram BCM. See PROGRAMMING  . After replacement, go to next step.
  16. Using scan tool, clear BCM DTCs. Operate vehicle within conditions to set DTC. If DTC B2470 resets, return to step  2 . If DTC B2470 does not reset, system is okay.
About FixVault