What Does B1471 Mean?
B1471 indicates the Body Control Module (BCM) has detected an open circuit in the headlamp input signal circuit. This means the BCM is not receiving the expected voltage signal from the headlamp switch or associated wiring when headlamps are commanded on. The BCM uses this input to control headlamp operation and related lighting functions.
Common Causes
35%
Open circuit or broken wire in headlamp switch input circuit between switch and BCM
30%
Faulty headlamp switch with internal open circuit or poor contact
20%
Corroded or loose connector pins at BCM or headlamp switch
10%
Blown fuse or faulty relay in headlamp switch power supply circuit
5%
Failed Body Control Module unable to read input signal
Diagnostic Steps
1
Step 1: Perform visual inspection of headlamp switch connector and BCM connector for corrosion, bent pins, or loose connections. Clean and secure any suspect connectors.
2
Step 2: Using a digital multimeter, measure voltage at the BCM headlamp input circuit terminal with headlamp switch in ON position. Expected reading should be battery voltage (12-14V). If no voltage present, proceed to switch testing.
3
Step 3: Backprobe the headlamp switch output terminal and verify voltage output when switch is activated. If voltage present at switch but not at BCM, trace and test wiring harness for opens using continuity testing with switch disconnected.
4
Step 4: Test headlamp switch ground circuit for proper continuity to chassis ground (should read less than 1 ohm resistance). Check headlamp switch power supply fuse and verify battery voltage at switch input terminal.
5
Step 5: If all wiring and connections test good, substitute known-good headlamp switch to verify switch operation. Clear codes and retest system functionality.
6
Step 6: If fault persists after all previous checks, verify BCM input circuit integrity by checking for voltage reference at BCM terminal according to wiring diagram specifications. BCM replacement may be necessary if all inputs test correctly but code remains.
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
B1471 indicates the Body Control Module (BCM) has detected an open circuit in the headlamp input signal circuit. This means the BCM is not receiving the expected voltage signal from the headlamp switch or associated wiring when headlamps are commanded on. The BCM uses this input to control headlamp ...
The most common cause of B1471 (Lamp Headlamp Input Circuit Open) is: Open circuit or broken wire in headlamp switch input circuit between switch and BCM
Typical repair costs for B1471 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Headlamps may not function properly or at all, creating serious safety hazard for nighttime driving and reduced visibility to other drivers. Vehicle should not be driven in darkness until repair is completed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1471 to identify the root cause.
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Quick Info
Category
Body
System
Body Electrical/Lighting System
Difficulty
Type
Manufacturer
Recommended Tools
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