What Does B1612 Mean?
This code indicates the Body Control Module (BCM) has detected an open circuit in the rear wiper mode select switch circuit. The BCM monitors the switch inputs that allow the driver to select different rear wiper operating modes (intermittent, low, high, etc.) and has detected a break in continuity or lack of expected voltage signal. This prevents the BCM from receiving proper input signals to control rear wiper operation.
Common Causes
35%
Faulty rear wiper mode select switch with internal open circuit or worn contacts
30%
Broken or damaged wiring harness between BCM and rear wiper switch, including corroded or loose connector terminals
20%
Disconnected or loose electrical connector at the rear wiper switch or BCM
10%
Failed Body Control Module with internal circuit fault preventing proper switch signal monitoring
5%
Blown fuse or open fusible link in the rear wiper switch power supply circuit
Diagnostic Steps
1
Step 1: Perform visual inspection of the rear wiper switch assembly and all associated connectors for obvious damage, corrosion, or disconnected terminals. Check connector lock mechanisms are fully engaged and pins are not backed out or corroded.
2
Step 2: Using a digital multimeter, check for battery voltage at the rear wiper switch power supply terminal with ignition on. Verify proper ground continuity at the switch ground terminal (should read less than 0.5 ohms to chassis ground).
3
Step 3: Disconnect the rear wiper switch connector and measure resistance across the switch terminals while cycling through all wiper mode positions. Compare readings to manufacturer specifications (typically 0-5000 ohms depending on position, infinity when open).
4
Step 4: With switch disconnected, measure continuity of the signal wire from the switch connector back to the BCM connector. Should read less than 5 ohms. Check for short to ground (should read infinite resistance) and short to power (should read no voltage present).
5
Step 5: If all wiring and switch test good, inspect BCM connector terminals for corrosion, damage, or terminal tension issues. Test BCM by monitoring switch input signal voltage at BCM connector with switch connected and operated through all positions.
6
Step 6: After repairs, clear codes, cycle the rear wiper through all mode selections multiple times, and verify code does not return. Test rear wiper operation in all modes to confirm proper functionality.
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an open circuit in the rear wiper mode select switch circuit. The BCM monitors the switch inputs that allow the driver to select different rear wiper operating modes (intermittent, low, high, etc.) and has detected a break in continuity ...
The most common cause of B1612 (Wiper Rear Mode Select Switch Circuit Open) is: Faulty rear wiper mode select switch with internal open circuit or worn contacts
Typical repair costs for B1612 range from $75 to $450, 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 rear wiper functionality. Repair can be scheduled at convenience, though rear visibility may be compromised in wet conditions which could pose a safety concern during inclement weather.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1612 to identify the root cause.
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Quick Info
Category
Body
System
Body Control System / Rear Wiper System
Difficulty
Type
Manufacturer
Recommended Tools
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