Rear Wiper Mode Switch Circuit Short to Ground
Diagnostic trouble code B1614 indicates that the Body Control Module (BCM) has detected a short to ground in the signal circuit of the rear wiper mode selector switch. This means the voltage on the switch input circuit is abnormally low (near 0 volts) when the BCM expects a reference voltage or specific resistance based on the selected position (OFF, INT, LOW, HIGH, WASH). As a result, the BCM cannot accurately read the switch position, disabling proper rear wiper operation.
1. Commonly Affected Makes
2. Most Common Causes
- Internal short to ground within the rear wiper mode selector switch
- Wiring harness for the switch signal circuit chafed or pinched against the body (short to ground)
- Corroded, dirty, or shorted terminals in the switch or BCM connector
- Internal failure of the BCM (pull-up driver or ADC input)
3. Symptoms You Will Notice
- Rear wiper inoperative or stuck in one mode
- Rear wiper operates continuously regardless of switch position
- Rear washer function may not work
4. Step-by-Step Diagnosis
Check for technical service bulletins (TSBs) related to rear wiper issues
Visually inspect the rear wiper switch and wiring for damage, corrosion, or pinched wires
Disconnect the switch and measure voltage at the signal wire (should be ~5V or battery voltage with switch disconnected); if 0V, suspect short to ground or BCM fault
Test the switch resistance across terminals in each position; compare to specifications
If wiring and switch are good, suspect BCM failure and perform BCM self-test or replacement
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but the rear wiper and washer will not function properly. This may affect rear visibility in rain or snow.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the switch, wiring repair, or BCM replacement is needed.