What Does B2185 Mean?
This diagnostic trouble code indicates that the Body Control Module (BCM) has detected an abnormal electrical short to ground in the rear wiper select switch circuit, specifically in the 'D' position or circuit path. The BCM monitors the switch input signals and has identified that voltage on this circuit is being pulled down to ground when it should be at a reference voltage or floating. This prevents proper operation of the rear wiper system and may cause the wipers to not function or operate erratically.
Common Causes
45%
Damaged or chafed wiring harness causing the switch circuit to contact ground, often in the liftgate hinge area or routing channels
30%
Failed rear wiper switch with internal short to ground due to corrosion, water intrusion, or mechanical failure
15%
Corroded or water-damaged connector pins at the rear wiper switch or BCM causing short circuit
10%
Failed Body Control Module with internal circuit fault on the wiper switch input channel
Diagnostic Steps
1
Step 1: Perform visual inspection of the rear wiper switch and all associated wiring, paying special attention to the liftgate hinge area and routing points where wiring may be pinched or chafed. Look for obvious damage, exposed copper, or burn marks.
2
Step 2: Disconnect the rear wiper switch connector and measure resistance from the 'D' circuit pin (consult wiring diagram for proper terminal) to chassis ground using a digital multimeter. Reading should be greater than 10,000 ohms (open circuit). If reading shows continuity or low resistance, the short is in the wiring harness between the switch and BCM.
3
Step 3: If wiring tested good, measure resistance across the switch terminals with the switch in various positions using the multimeter. Compare readings to manufacturer specifications. Internal short will show unexpected continuity to ground in one or more switch positions.
4
Step 4: If switch and visible wiring are good, inspect the BCM connector for corrosion, pushed-back pins, or water intrusion. Disconnect BCM and measure resistance from the switch circuit wire to ground at the BCM connector side. This isolates whether the short is in the harness or within the BCM itself.
5
Step 5: Repair or replace identified faulty component (wiring, switch, or BCM), clear codes, and cycle the rear wiper through all functions to verify proper operation and confirm no codes return.
Estimated Repair Cost
$100 - $650
Parts + labor, varies by vehicle and location
This diagnostic trouble code indicates that the Body Control Module (BCM) has detected an abnormal electrical short to ground in the rear wiper select switch circuit, specifically in the 'D' position or circuit path. The BCM monitors the switch input signals and has identified that voltage on this c...
The most common cause of B2185 (Rear Wiper Select Switch "D" Short to Ground) is: Damaged or chafed wiring harness causing the switch circuit to contact ground, often in the liftgate hinge area or routing channels
Typical repair costs for B2185 range from $100 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this affects only rear wiper operation and does not impact vehicle control or primary safety systems. Repair at convenience, though reduced rear visibility in inclement weather should be considered when planning the repair timeline.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2185 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Wiper System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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