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DTC codes / B06xx · Airbags, seats, doors, lights and comfort systems / B0610

B0610Mirror Heater Circuit

B0610 indicates that the body control module (BCM) has detected an open circuit, short to ground, or short to voltage in the mirror heater circuit, which powers the heating element inside the side-view mirror. The BCM monitors the current flow through the heater and sets this code when the expected current is outside the normal range.

SystemBody
Code typeGeneric (all makes)
SeverityLow
Fix difficultyIntermediate
AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

  • The side-view mirror heating function does not work, so the mirror glass stays fogged or frosted in cold or damp weather.
  • The mirror heater may stay on continuously, causing the mirror glass to become unusually hot to the touch.
  • Often no symptoms besides the warning light, because the mirror heater is a comfort feature and many drivers never notice its failure.
  • A blown fuse for the mirror heater circuit, which may also affect other body functions on the same fuse.
  • In some vehicles, the BCM may disable other unrelated body features as a protective strategy when a short is detected.
  • The mirror glass may show uneven heating, with only part of the surface clearing.

Common causes, most likely first

  1. A failed mirror heater element (open circuit) inside the mirror glass assembly, which is the most common cause.
  2. Corroded or damaged wiring and connector pins at the mirror, door jamb, or BCM, often due to water intrusion.
  3. A short to ground or short to voltage in the mirror heater wiring harness, typically where the harness flexes at the door hinge.
  4. A faulty body control module (BCM) output driver for the mirror heater circuit, though this is less common.
  5. A blown fuse or faulty relay that supplies power to the mirror heater circuit.
  6. Aftermarket mirror glass or accessories installed incorrectly, causing a mismatch in resistance.

How to diagnose and fix it

  1. Check the fuse and relay for the mirror heater circuit, and replace any blown fuse or faulty relay.
  2. Disconnect the mirror heater connector and measure the resistance of the heater element; compare to the manufacturer's specification to confirm an open or shorted element.
  3. Inspect the wiring harness and connector pins at the mirror, door jamb, and BCM for corrosion, chafing, or loose terminals, and repair as needed.
  4. With the heater commanded on, measure voltage and current at the mirror connector to verify the BCM output and detect a short to ground or voltage.
  5. If the element and wiring test good, substitute a known-good BCM or reprogram the existing BCM, following the manufacturer's procedures.
  6. Clear the code and verify the repair by activating the mirror heater and confirming the code does not return.

Mirror heater faults that fool technicians

  • A mirror heater element can fail intermittently when cold, so a resistance check at room temperature may pass even though the code sets only in freezing weather.
  • Water intrusion into the mirror housing or door connector is a frequent hidden cause, and the corroded pins often look fine until the connector is opened and inspected.
  • The BCM may set B0610 for a short to voltage even when the heater works normally, because a chafed wire can back-feed voltage from another circuit in the same harness.
  • Aftermarket mirror glass with an incorrect resistance can trigger this code even though the heater functions, so always compare the replacement part to the original specification.
  • A weak or failing battery can cause the BCM to misreport heater circuit current, so check charging system health before condemning the BCM.

Can I keep driving with B0610?

The vehicle is safe to drive because the mirror heater is a comfort feature and does not affect steering, braking, or visibility laws in most regions. Avoid using the mirror heater until the fault is repaired, and clear the mirror glass manually if it fogs, as a shorted circuit could drain the battery or damage the BCM over time.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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