B1824: Rear Wiper Park Switch Circuit High Voltage
The B1824 code indicates that the Body Control Module (BCM) or rear wiper control module has detected an abnormally high voltage on the park position sensor input circuit for the rear wiper. This sensor monitors the rest position of the rear wiper arm and sends a variable voltage signal to the control module. A 'short to battery' means the circuit is receiving battery voltage (approximately 12V) constantly or at an inappropriate time, instead of the expected variable signal. This prevents the system from correctly determining whether the wiper is in the park position.
1. Commonly Affected Makes
2. Most Common Causes
- Wiring in the park position sensor circuit shorted to battery voltage
- Rear wiper park position sensor damaged or with altered internal resistance
- Sensor connector corroded, oxidized, or with damaged pins
- Rear wiper control module or BCM with internal failure
- Faulty splice or electrical connection in the liftgate harness (area prone to flexing)
3. Symptoms You Will Notice
- Rear wiper does not park correctly or stops in random positions
- Rear wiper may not operate at all or operates intermittently
4. Step-by-Step Diagnosis
Scan for codes and verify B1824 is present
Inspect the rear wiper park sensor connector and wiring for corrosion, damage, or shorts to battery voltage
Check the sensor's resistance and voltage signal with a multimeter
Test the wiring harness in the liftgate area for breaks or shorts
If wiring and sensor are good, suspect a faulty BCM or rear wiper control module
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but the rear wiper may not function properly, which could reduce visibility in rain or snow. It is recommended to have it repaired soon.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the issue is a simple wiring repair or requires replacing the sensor or control module.