Engine-Codes - Generic - B1508

B1508 Code - Flash To Pass Switch Circuit Open

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

|B1508 code possible causes

  • Faulty Headlamp Switch
  • Headlamp Switch harness is open or shorted
  • Headlamp Switch circuit poor electrical connection
  • Faulty Smart Junction Box (SJB)

|How is the B1508 code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

|What is the cost to diagnose the B1508 code

Labor: 1.0

The cost to diagnose the B1508 code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

|What are B1508 code possible symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

|What is B1508 code meaning?

The Smart Junction Box (SJB) sends reference signals to the headlamp switch through circuits. When the headlamp switch is placed in the HEADLAMPS ON position, the voltage signal is routed to ground through the circuit. If the SJB detects a fault with the headlamp switch inputs, the SJB turns the exterior lamps on by default. When the SJB detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the LOW BEAM position, the SJB sends voltage through circuits to the low beam headlamps. When the SJB detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the HIGH BEAM position, the SJB sends voltage through circuits to the high beam headlamps. The SJB sends a reference signal to the multifunction switch through circuits CLF27 (GN/BN) and CLF17 (WH/OG). When the multifunction switch is placed in the FLASH-TO-PASS or HIGH BEAM position, the voltage signal is routed to ground. When the SJB detects a request for the flash-to-pass, the SJB sends voltage to the high beam headlamps. The OBDII codes when the SJB detects a short to ground from the flash-to-pass input circuit.

|Need more information with the B1508 code?

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|B1508 code information for specific makes

|Need help with a B1508 code?

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