B1784 – Mirror Passenger Up Circuit Short To Battery

By Fixitfor.us |
Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

The ODBII code B1784 indicates a short circuit in the passenger side mirror’s “up” control circuit, causing it to be continuously powered as if it is connected directly to the battery.

The severity of ODBII code B1784 is moderate.

Common Causes For: B1783 Mirror Passenger Up Circuit Open

  • Shorted wiring or connectors in the passenger mirror circuit.
  • Faulty passenger side mirror switch.
  • Defective passenger side mirror motor.
  • Corroded or damaged electrical connections.
  • Malfunctioning body control module (BCM).

Common misdiagnosis for B1784 Mirror Passenger Up Circuit Short To Battery

  • Faulty passenger side mirror switch
  • Damaged wiring harness
  • Shorted wiring in the door panel
  • Malfunctioning body control module (BCM)
  • Defective passenger side mirror motor
  • Issues with the vehicle’s electrical system
  • Incorrectly installed aftermarket accessories

Common Troubleshooting Steps

The OBD-II code B1784 indicates a problem with the passenger side mirror’s “up” circuit, specifically a short to battery. This can prevent the mirror from functioning correctly. Here are some common troubleshooting steps to diagnose and resolve this issue:

  • Visual Inspection: **Wiring and Connectors: Check the wiring harness and connectors leading to the passenger side mirror. Look for any signs of damage, fraying, or corrosion.
  • **Mirror Assembly: Inspect the mirror assembly itself for any physical damage or signs of water intrusion.
  • Check for Short Circuits: **Multimeter Testing: Use a multimeter to check for continuity in the mirror’s wiring. Disconnect the mirror connector and test the wires for continuity to ground or battery voltage.
  • **Resistance Check: Measure the resistance of the mirror motor. If it is too low (indicating a short), the motor may need to be replaced.
  • Inspect the Switch: **Switch Functionality: Test the mirror control switch to ensure it is functioning correctly. A faulty switch can send incorrect signals to the mirror motor.
  • **Wiring to Switch: Check the wiring from the switch to the mirror for any shorts or damage.
  • Check the Power Supply: **Voltage Check: With the mirror connector still disconnected, check for proper voltage at the connector when the switch is activated. You should see battery voltage when the switch is pressed.
  • **Ground Connection: Ensure that the ground connection for the mirror is solid and free of corrosion.
  • Scan for Additional Codes: **Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues.
  • Inspect the Body Control Module (BCM): **BCM Functionality: If all wiring and components appear to be in good condition, the issue may lie within the BCM. Check for any software updates or known issues with the BCM related to mirror control.
  • Repair or Replace Components: **Repair Wiring: If any damaged wiring or connectors are found, repair or replace them as necessary.
  • **Replace Faulty Components: If the mirror motor, switch, or BCM is determined to be faulty, replace the component.
  • Clear Codes and Test: After making repairs, clear the trouble codes using the OBD-II scanner and test the mirror operation to see if the issue is resolved.
  • Consult Service Manual: If the problem persists, consult the vehicle’s service manual for specific wiring diagrams and troubleshooting procedures related to the mirror system.
  • Professional Help: If you are unable to diagnose or fix the issue, consider seeking help from a professional mechanic or an automotive electrician. By following these steps, you should be able to identify and resolve the issue related to the B1784 code.

Leave a Comment

You must be logged in to post a comment.