What Does B1582 Mean?
This code indicates the Body Control Module (BCM) has detected a short to ground in the dimmer panel increase input circuit. This circuit allows the driver to brighten the instrument panel and interior lighting through a switch or button. The BCM has identified that the signal wire for the brightness increase function is making unintended contact with ground, preventing proper operation.
Common Causes
40%
Damaged or chafed wiring in the dimmer switch harness causing direct short to ground
30%
Failed dimmer switch assembly with internal short to ground
20%
Corroded or damaged connector pins at dimmer switch or BCM causing ground fault
10%
Water intrusion or moisture in dimmer switch causing short circuit
Diagnostic Steps
1
Step 1: Visually inspect the dimmer switch assembly and surrounding trim for signs of damage, moisture intrusion, or improper installation that could cause wire contact with ground
2
Step 2: Disconnect the dimmer switch connector and use a digital multimeter to measure resistance between the increase input circuit pin and ground - reading should be infinite (open circuit). If resistance is below 5 ohms, the short is in the wiring harness
3
Step 3: With dimmer switch disconnected, check resistance at the BCM connector for the same circuit - if short is still present, the fault is in the harness between switch and BCM. If short disappears, replace dimmer switch
4
Step 4: If harness is suspected, perform continuity tests along the wire route, checking for pinch points at door jambs, under dash mounting brackets, and near metal edges where chafing occurs
5
Step 5: Repair or replace damaged wiring, connectors, or switch as identified, then clear codes and verify dimmer function operates correctly through full range without code returning
Estimated Repair Cost
$75 - $350
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a short to ground in the dimmer panel increase input circuit. This circuit allows the driver to brighten the instrument panel and interior lighting through a switch or button. The BCM has identified that the signal wire for the brightnes...
The most common cause of B1582 (Dim Panel Increase Input Circuit Short To Ground) is: Damaged or chafed wiring in the dimmer switch harness causing direct short to ground
Typical repair costs for B1582 range from $75 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is safe to continue driving as it only affects interior lighting brightness adjustment. The vehicle remains fully operational, though you may be unable to adjust instrument panel dimming, which could cause minor inconvenience during night driving.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1582 to identify the root cause.
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Quick Info
Category
Body
System
Interior Lighting Control System
Difficulty
Type
Manufacturer
Recommended Tools
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