Introduction:

The B1611 diagnostic trouble code (DTC) indicates a malfunction within the rear wiper mode select switch circuit in a vehicle. This circuit is responsible for communicating the driver's desired rear wiper operation (e.g., intermittent, low, high, off) to the vehicle's body control module (BCM) or wiper control module. A failure in this circuit can result in the rear wiper not functioning correctly, or at all, potentially impacting visibility and safety, especially in inclement weather.

Comprehensive Table: B1611 Wiper Rear Mode Select Switch Circuit Failure

Aspect Description Possible Causes
Definition Indicates a problem with the electrical circuit connected to the rear wiper mode select switch. Specifically, the BCM or wiper control module detects an unexpected voltage level or signal from the switch circuit. Short circuit to ground or voltage: A wire in the circuit is making unintended contact with the vehicle chassis (ground) or a power source. Open circuit: A break in the wiring, preventing the signal from reaching the control module. Faulty Rear Wiper Mode Select Switch: The switch itself is malfunctioning internally. Corroded or Damaged Connectors: Oxidation or physical damage to the connectors in the circuit. BCM or Wiper Control Module Failure: (Rare) The control module responsible for interpreting the switch signal is malfunctioning. Wiring Harness Damage: Physical damage to the wiring harness, such as cuts, pinches, or abrasions. Software Glitch: (Rare) A temporary software issue within the BCM or wiper control module.
Symptoms Rear wiper not functioning at all. Rear wiper operating continuously regardless of switch position. Rear wiper operating erratically or intermittently. Rear wiper only functioning in one mode (e.g., only high speed). Check Engine Light or other warning lights illuminated. Other electrical issues in the vehicle (in rare cases, due to shared circuits). Same as Possible Causes, but viewed from the perspective of what the driver observes.
Diagnostic Steps Visual Inspection of Wiring and Connectors. Testing the Rear Wiper Mode Select Switch. Checking for Short Circuits and Open Circuits. Verifying Power and Ground to the Wiper Motor. Scanning for Other Diagnostic Trouble Codes. Consulting Vehicle-Specific Wiring Diagrams. Testing the BCM or Wiper Control Module (if other tests are inconclusive). N/A - These are the procedures used to identify the causes.
Possible Solutions/Repairs Repairing or Replacing Damaged Wiring. Cleaning or Replacing Corroded Connectors. Replacing the Rear Wiper Mode Select Switch. Replacing the Wiper Motor (if the motor itself is faulty). Replacing the BCM or Wiper Control Module (as a last resort). Clearing Diagnostic Trouble Codes. N/A - These are the actions taken based on the diagnosed cause.
Tools Required Multimeter. Wiring Diagram. Socket set and wrenches. Wire stripper and crimper. Connector cleaning tools. Scan tool (OBD II scanner). Test light. Digital Volt Meter (DVM). N/A
Severity Moderate. The rear wiper is important for visibility in inclement weather, making this a safety concern. N/A
Related DTCs Other DTCs related to the wiper system, such as those for the front wiper motor, washer pump, or BCM. N/A
Component Location Rear Wiper Mode Select Switch: Typically located on the steering column stalk or dashboard. BCM or Wiper Control Module: Varies by vehicle; consult a service manual. Rear Wiper Motor: Located on the rear hatch or liftgate. Wiring Harness: Runs along the vehicle's body, often under the headliner or along the door sills. N/A

Detailed Explanations:

Definition: The B1611 code specifically points to an issue within the electrical circuit that connects the rear wiper mode select switch to the vehicle's computer. The Body Control Module (BCM) or a dedicated wiper control module monitors the voltage or signal coming from this switch. When the signal is out of the expected range, the B1611 code is triggered, indicating a potential short, open, or faulty component within the circuit.

Symptoms: The symptoms of a B1611 code can manifest in several ways. The most common is a completely inoperative rear wiper. Alternatively, the wiper might run constantly, regardless of the switch position. You might also experience erratic or intermittent operation, or the wiper might be stuck in only one speed setting. In some cases, the check engine light or another warning light may illuminate on the dashboard. Rarely, the issue can cause other unrelated electrical problems due to shared circuits within the vehicle's electrical system.

Diagnostic Steps:

  1. Visual Inspection of Wiring and Connectors: Begin by thoroughly inspecting the wiring harness and connectors associated with the rear wiper circuit. Look for any signs of physical damage, such as cuts, abrasions, or pinched wires. Pay close attention to the connectors at the rear wiper mode select switch, the wiper motor, and the BCM or wiper control module. Check for corrosion on the connector pins, which can impede electrical conductivity.

  2. Testing the Rear Wiper Mode Select Switch: Use a multimeter to test the functionality of the rear wiper mode select switch. Consult the vehicle's wiring diagram to identify the correct terminals to test. Check for continuity in each switch position. The switch should have the correct resistance values in each position. If the switch fails this test, it is likely faulty and needs to be replaced.

  3. Checking for Short Circuits and Open Circuits: Use a multimeter to check for short circuits to ground or voltage within the wiring harness. Disconnect the switch and the control module to isolate the circuit. Check for continuity between each wire in the circuit and ground. There should be no continuity. Also, check for continuity between each wire and a known voltage source. Again, there should be no continuity. Use the multimeter to check for open circuits by testing the continuity of each wire in the circuit. There should be continuity between the two ends of each wire.

  4. Verifying Power and Ground to the Wiper Motor: Ensure that the rear wiper motor is receiving the correct power and ground signals. Use a multimeter to check the voltage at the motor's power terminal. The voltage should match the vehicle's battery voltage. Also, check the continuity between the motor's ground terminal and the vehicle's chassis. There should be good continuity.

  5. Scanning for Other Diagnostic Trouble Codes: Use an OBD II scanner to check for any other diagnostic trouble codes that might be related to the wiper system or the BCM. Other codes can provide valuable clues about the root cause of the problem.

  6. Consulting Vehicle-Specific Wiring Diagrams: Obtain a vehicle-specific wiring diagram for the rear wiper system. This diagram will provide detailed information about the wiring routing, connector locations, and component pinouts. This information is essential for accurate diagnosis and repair.

  7. Testing the BCM or Wiper Control Module (if other tests are inconclusive): This is usually the last step, as the BCM or wiper control module is the most expensive component. Before replacing the module, double-check all other components and wiring. If all other tests are negative, the module may be faulty. This often requires specialized diagnostic equipment and expertise.

Possible Solutions/Repairs:

  • Repairing or Replacing Damaged Wiring: If you find damaged wiring, repair it using proper splicing techniques and heat-shrink tubing. If the damage is extensive, replace the entire section of wiring.

  • Cleaning or Replacing Corroded Connectors: Clean corroded connectors with a specialized connector cleaner. If the corrosion is severe, replace the connector.

  • Replacing the Rear Wiper Mode Select Switch: If the rear wiper mode select switch is faulty, replace it with a new one.

  • Replacing the Wiper Motor (if the motor itself is faulty): If the wiper motor is not receiving power or ground, or if it is making unusual noises, it may be faulty and need to be replaced.

  • Replacing the BCM or Wiper Control Module (as a last resort): Replacing the BCM or wiper control module is usually a last resort, as it is the most expensive repair. Ensure all other components and wiring are tested before replacing the module. This may require programming after installation.

  • Clearing Diagnostic Trouble Codes: After completing the repairs, clear the diagnostic trouble codes using an OBD II scanner.

Tools Required:

  • Multimeter: Essential for testing voltage, continuity, and resistance.
  • Wiring Diagram: Crucial for understanding the circuit layout and identifying components.
  • Socket set and wrenches: For removing and installing components.
  • Wire stripper and crimper: For repairing or replacing wiring.
  • Connector cleaning tools: For cleaning corroded connectors.
  • Scan tool (OBD II scanner): For reading and clearing diagnostic trouble codes.
  • Test light: Can be used to check for power and ground.
  • Digital Volt Meter (DVM): Another name for a multimeter.

Severity: A B1611 code is considered a moderate severity issue. While it might not immediately disable the vehicle, a malfunctioning rear wiper can significantly reduce visibility in rain, snow, or other adverse conditions. This can compromise safety and increase the risk of accidents.

Related DTCs:

Several other DTCs might be related to the wiper system and could appear alongside B1611. These might include codes for the front wiper motor, washer pump, or the BCM itself. Addressing these related codes can provide a more comprehensive solution to the problem.

Component Location:

  • Rear Wiper Mode Select Switch: Typically located on the steering column stalk or dashboard, integrated with other wiper controls.
  • BCM or Wiper Control Module: Location varies significantly by vehicle; consult a service manual for specific placement. Often found under the dashboard or in the engine compartment.
  • Rear Wiper Motor: Located on the rear hatch or liftgate, directly connected to the wiper arm.
  • Wiring Harness: Runs along the vehicle's body, often under the headliner, along the door sills, or within the rear hatch.

Frequently Asked Questions:

  • What does the B1611 code mean? It indicates a problem with the electrical circuit of the rear wiper mode select switch. It means the BCM or wiper control module is not receiving the expected signal from the switch.

  • Can I drive with a B1611 code? Yes, but it's not recommended, especially in bad weather. A non-functional rear wiper can severely limit visibility.

  • Is the B1611 code easy to fix? It depends on the cause. Simple issues like a loose connector are easy to fix, while a faulty BCM is more complex.

  • How much does it cost to fix a B1611 code? The cost varies depending on the repair needed. A new switch might be inexpensive, while a BCM replacement can be costly.

  • Can I fix the B1611 code myself? If you have basic electrical knowledge and tools, you can attempt some of the diagnostic steps. However, complex issues might require a professional.

Conclusion:

The B1611 code signals a problem within the rear wiper mode select switch circuit, which can lead to impaired rear visibility. Systematic diagnosis, starting with simple checks and progressing to more complex testing, is crucial for identifying and resolving the issue effectively, ensuring safe driving in all weather conditions.